a4 jetty design report

Preliminary Jetty Design

Doris North Project, Hope BayNunavut, Canada

Prepared for:

Miramar Hope Bay LimitedSuite 300, 889 Harbourside Drive

North Vancouver, BC V7P 3S1Canada

Prepared by:

SRK Project No. 1CM014.006

October 2005

Preliminary Jetty Design, Doris North Project Hope Bay, Nunavut, Canada

Miramar Hope Bay Limited Suite 300, 889 Harbourside Drive

North Vancouver, BC V7P 3S1

SRK Consulting (Canada) Inc.

Suite 800, 1066 West Hastings Street Vancouver, B.C. V6E 3X2

Tel: 604.681.4196 Fax: 604.687.5532

E-mail: [email protected] Web site: www.srk.com

SRK Project Number 1CM014.006

October 2005

Author

Maritz Rykaart, Ph.D., P.Eng. Senior Engineer

Reviewed by

Cam Scott, P.Eng. Principal

SRK Consulting Preliminary Jetty Design, Doris North Project, Hope Bay, Nunavut, Canada Page 1

MR/spk PreliminaryJettyDesign.Report.1CM014 006.emr.20051001_FINAL-Oct21.2005.doc, Oct. 21, 05, 2:26 PM October 2005

Table of Contents

1 Introduction .................................................................................................................. 1 1.1 Background ......................................................................................................................... 1 1.2 Scope of Work..................................................................................................................... 1 1.3 Report Organization ............................................................................................................ 1

2 Sealift Off-Loading Alternatives ................................................................................. 3 2.1 Introduction ......................................................................................................................... 3 2.2 Sealift Types ....................................................................................................................... 3

2.2.1 Deep Draft Vessels (Cargo Ships) ..........................................................................................3 2.2.2 Shallow Draft Barges...............................................................................................................4

2.3 Alternative Barge Off-Loading Locations ............................................................................ 5 2.3.1 Existing Barge Landing Site ....................................................................................................5 2.3.2 Roberts Bay Deep Water Port Site .........................................................................................5 2.3.3 East Shore Peninsula (Jetty Site #2) ......................................................................................6 2.3.4 Southern Roberts Bay Shoreline Site (Jetty Site #1 - Preferred Location) .............................7

3 Investigations............................................................................................................... 8 3.1 Introduction ......................................................................................................................... 8 3.2 Barge Access ...................................................................................................................... 8 3.3 Bathymetry .......................................................................................................................... 8 3.4 Shoreline Erosion Processes .............................................................................................. 9 3.5 Geotechnical Foundation Conditions .................................................................................. 9

3.5.1 EBA (1997) Roberts Bay Port Site Geotechnical Investigation...............................................9 3.5.2 Jetty Foundation Drilling (SRK Phase I Investigation) ..........................................................10 3.5.3 In-Situ Vane Shear Testing (SRK Phase II Investigation).....................................................11

4 Conceptual Design Alternatives ............................................................................... 12 4.1 Introduction ....................................................................................................................... 12 4.2 Option 1: Continuous Rock Fill Jetty ................................................................................. 12 4.3 Option 2: Rock Fill Jetty with Arch Culverts ...................................................................... 13 4.4 Option 3: Rock Fill Buttressed Jetty with Prefabricated Decks ......................................... 13 4.5 Option 4: Conventional Piled Jetty with Prefabricated Decks ........................................... 14 4.6 Option 5: Cellular Sheet Pile Jetty .................................................................................... 14 4.7 Option 6: Rock Fill Jetty on In-Situ Frozen Ground........................................................... 15 4.8 Option 7: Bay Dredging & Rock Fill Jetty .......................................................................... 15

5 Preferred Design ........................................................................................................ 17 5.1 Selection of Preferred Design ........................................................................................... 17 5.2 Design Criteria .................................................................................................................. 17 5.3 Design Detail ..................................................................................................................... 19 5.4 Optimization Opportunities................................................................................................ 19 5.5 Construction ...................................................................................................................... 20 5.6 Maintenance...................................................................................................................... 21 5.7 Decommissioning.............................................................................................................. 21

6 References.................................................................................................................. 23



List of Tables

Table 1: Summary of Jetty Design Criteria..................................................................................... 18

List of Figures

Figure 1: Site Map Figure 2: Sealift Off-Loading Alternative Locations Figure 3: Roberts Bay Bathymetry (per Frontier Geosciences Inc.) Figure 4: Preferred Jetty Location Plan Figure 5: In-Situ Vane Shear Testing and Drill Hole Locations Figure 6: Inferred Jetty Centerline Profile Figure 7: Option 1: Continuous Rock Fill Jetty Plan Figure 8: Option 1: Continuous Rock Fill Jetty Section Figure 9: Option 2: Rock Fill Jetty with Arch Culverts Plan Figure 10: Option 2: Rock Fill Jetty with Arch Culverts Section Figure 11: Option 3: Rock Fill Buttressed Jetty with Prefabricated Decks Plan Figure 12: Option 3: Rock Fill Buttressed Jetty with Prefabricated Decks Section Figure 13: Option 4: Conventional Piled Jetty with Prefabricated Decks Plan Figure 14: Option 4: Conventional Piled Jetty with Prefabricated Decks Section Figure 15: Option 5: Cellular Sheet Pile Jetty Plan Figure 16: Option 5: Cellular Sheet Pile Jetty Section Figure 17: Option 7: Bay Dredging & Rock Fill Jetty Plan Figure 18: Option 7: Bay Dredging & Rock Fill Jetty Section Figure 19: Typical Plan of Continuous Rock Fill Jetty Figure 20: Typical Section of Continuous Rock Fill Jetty (Section A-A) Figure 21: Typical Section of Continuous Rock Fill Jetty (Section B-B) Figure 22: Typical Plan for Possible Optimized Jetty Figure 23: Typical Section for Possible Optimised Jetty

List of Appendixes

Appendix A MHBL Technical Memorandum Appendix B Roberts Bay Bathymetry Report (Frontier Geosciences Inc. 2003) Appendix C Summary of Roberts Bay Geotechnical Properties Appendix D Phase I Foundation Investigation (SRK 2004) Appendix E Phase II Foundation Investigation (SRK 2005) Appendix F Technical Memorandum Outlining Preliminary Jetty Design Calculations Appendix G Typical Geogrid Specifications



1 Introduction

1.1 Background

Miramar Hope Bay limited (MHBL) is the planning on developing a small gold mine on the Arctic coastline in the Hope Bay Belt, Nunavut, Canada. This project, the Doris North Project is situated approximately 4 km inland from Roberts Bay, is remote and all equipment and supplies can only be economically transported to site via annual sealift during a short open water season in the late summer.

Details of the project are documented in SRK (2005a), and stipulate the need for a sealift off-loading facility (jetty) in Roberts Bay (Figure 1). This report outlines preliminary engineering that has been completed in support of the jetty.

1.2 Scope of Work

The jetty design presented in the Preliminary Surface Infrastructure Design Report for the Doris North Project, SRK (2005a) was selected based on baseline data and engineering investigations since 1997. The bulk of the engineering work has been completed by SRK Consulting (Canada) Inc. (SRK) on behalf of MHBL from 2002 onwards. Significant portions of this later work have never been formally documented. MHBL subsequently contracted SRK to document all background data feeding into the design of a jetty in a single report. The report would culminate in the selection of a jetty alternative, complete with preliminary design details. The report therefore contains the following information;

Review of alternative sealift options; Summary discussion of all relevant baseline and geotechnical data; Review of alternative jetty designs; Complete preliminary design for the preferred jetty alternative.

This report is furthermore intended to provide the information necessary to satisfy additional information requests and technical concerns raised during the conformity review process and Technical Meetings held for the Project in Yellowknife in August 2005.

1.3 Report Organization

Section 2 of this report presents a discussion of the alternative sealift options that MHBL had considered for the Doris North Project. These alternatives consist of shallow draft barges mobilised from Hay River, Northwest Territories (NT), versus deep draft cargo ships mobilized from Montreal, Quebec.



MHBL has initiated a series of technical studies to collect baseline and engineering data pertaining to the design of a jetty at Roberts Bay. This data is summarized in Section 3 of this report, and in most cases, detailed supporting documentation referred to in this section has been included as Appendices.

Seven different alternative jetty designs have been proposed for the Doris North Project. Section 4 of this report describes these alternatives, and explains why a continuous rock fill jetty has been selected as the preferred alternative.

Section 5 concludes with details of the preliminary design of a continuous rock fill jetty for the Doris North Project. These details include design criteria, construction procedures and reclamation plans.



2 Sealift Off-Loading Alternatives

2.1 Introduction

This section of the report summarizes the sealift alternatives that were considered for the Doris North Project. The first factor that MHBL had to consider was the type of sealift that would be used, and the second was the preferred jetty location.

2.2 Sealift Types

2.2.1 Deep Draft Vessels (Cargo Ships)

Deep draft vessels (standard cargo ships) cruise annually into the Arctic to service various communities and industry. Canadian registered vessels are staged out of Montreal, Quebec, and travel down the St. Lawrence River, around the eastern coastline into the Arctic. These ships vary in size and can hold anything from 9 million to 50 million tonnes of fuel and deck cargo and carry their own barges onto which goods are reloaded for transfer to land.

The open water season for ships into Roberts Bay is usually a four to eight week period between August and September. The ships can travel significantly faster than barges, and the shipping time between Montreal and Roberts Bay would generally be less than four weeks. Assuming arrival in Roberts Bay by the last week in August implies that MHBL would have to have their supplies ready for shipping in Montreal by the end of July.

Montreal is a major international shipping port and most supplies and fuel can be sourced locally at competitive prices, with very little order and delivery lead time. This offers MHBL opportunities for saving, as well as further reducing the annual order lead time for re-supply.

The per tonne shipping rate for supplies and fuel on these large ships are significantly less than for the barges (see Section 2.2.2), provided MHBL secures the entire cargo load for the ship. The annual re-supply volumes that MHBL envisage, will, however not come close to the ship cargo capacity, and as such the cost benefit is lost.

The ships offload their cargo onto the barges with cranes. These cranes have a 13 tonne maximum capacity, and although this would be acceptable for normal operating re-supply, this restriction would preclude transportation of the construction equipment, and mill modules.

In summary, even though the increased procurement time, and better fuel price is advantageous to MHBL, these savings are weaned away as a result of MHBL not being able to take full advantage of the large cargo capacity of the ships. Furthermore, the crane capacity effectively precludes the use of ships for the initial two shipping seasons. This was therefore eliminated as a viable sealift alternative for the Doris North Project.



2.2.2 Shallow Draft Barges

The most common form of sealift in the Canadian Arctic, especially the western and central Arctic is shallow draft barges staged from Hay River, NT. These barge trains are pulled by tugs. There is not a lot of choice when it comes to the selection of a shipping company, with the Northern Transportation Company Limited (NTCL) being the only company operating barges (www.ntcl.com).

In order to take advantage of the short open water season, the fully loaded barges have to leave Hay River by early July every year. Off-loading of goods is done on a loose schedule which depends to a large extent of weather and ice conditions. Also, since barges often contain goods destined for more than one location, offloading is staged.

MHBL currently uses barges for the re-supply of their exploration activities in the Hope Bay Belt. On average the barges arrive in Roberts Bay by the second to third week of August. In order to meet this deadline, the barge shipping company usually requires all goods to be in Hay River by the end of June. That means that the average delivery time for goods to site, excluding delivery time to Hay River, is at least eight weeks.

Hay River is a large re-supply depot for the Arctic, but compared to Montreal, it is expensive and time consuming to get supplies and fuel to Hay River.

The biggest barge currently in use is the NT 1500 Series, with a fully loaded capacity of 2,190 tonnes. There are future plans to put a new NT 2000 Series barge in production. This barge will increase the cargo capacity by almost a factor of two.

With the aid of skilled tug skippers, the barges are highly manoeuvrable, and can be used in extremely shallow water. Often the barges are simply rammed onto the shoreline with the tugs with no need for offshore structures.

MHBL opted to continue using the barge and tug alternative for the annual sealift for the Doris North Project. Although the barges are more expensive per tonne of transported goods when compared with a fully laden ship out of Montreal, the annual re-supply tonnage for the Project is not sufficient to fill up the ships, and therefore MHBL cannot benefit from reduced shipping rates.

Furthermore, since there is no natural deep water dock to offload directly from a ship, all goods will have to be reloaded to barges before it can be moved closer to shore for final offloading. The offloading facilities that MHBL would have to construct would therefore be the same irrespective of which sealift option is selected.



2.3 Alternative Barge Off-Loading Locations

2.3.1 Existing Barge Landing Site

MHBL brings in an annual sealift to re-supply their exploration activities in the Hope Bay Belt. This sealift is via barges from NTCL staged out of Hay River. There are no permanent barge off-loading facilities in Roberts Bay. The barges are offloaded by pushing them directly onto a gravel beach located on the south western shore of the Bay (Figure 2).

This gravel beach and the surrounding soils are permafrost of marine origin, and based on aerial photography and other regional geotechnical investigations and thermal monitoring (EBA 1997; SRK 2005a, b) the soils are likely to be ice-rich. The beach itself measures approximately 30 x 30 m and provides a stable off-loading platform for the barges.

The benefits of continuous use of this site for the duration of the Doris North Project are clear. It is located on the western side of the Bay, which is well protected from the prevailing winds and it may not require the construction of a permanent off loading facility. In the event that the practice of beaching the barges is considered to pose potential significant environmental effects, a dock (jetty) could be constructed offshore; however, this structure would be relatively modest in size.

Therefore, to make this site functional as a permanent off-loading facility a dock (jetty) would have to be constructed to protect the beach and an off loading area away from the beach on a permanent pad would be required. This site is approximately 6 km from the camp/mill site (SRK 2005a), requiring an additional 1.5 km of permanent all-weather road, including a major stream crossing. Alternatively equipment can be off-loaded, secured and transported via winter road.

Based on all of these factors, MHBL decided not to pursue the use of this site as a permanent jetty location for the Doris North Project.

2.3.2 Roberts Bay Deep Water Port Site

Historic site development studies (EBA 1997) within the Hope Bay belt identified a preferred deep water sea terminal location on the west side of Roberts Bay (Figure 2). At that time the concept was to use deep water ships for the annual sealift, and to transfer goods to barges for offloading at the terminal.

The proposed port site is located in waters reaching 50 m depth with basalt rock outcrop on the west shore serving as terminal facility area. Bathymetry data from a local hydrographic survey showed that the sea bottom drops off steeply toward the east, reaching 35 m depth within 100 m offshore. The basalt outcrop is surrounded by permafrost marine-derived sediments on the west side.

Based on field investigations carried out in 1997 it was concluded that a balanced bedrock cut and fill would be required to grade the site by removing the top of the bedrock outcrop and filling the



marine lowland. This will create a portion of the site where support structures for the dock could be founded.

Two options for barge berthing were considered; (a) a steel sheetpile cellular structure and (b) a floating transition ramp using either a pontoon or small barge moored at the shore side.

The sheetpile cellular structure would require driving piles into bedrock (approximately 16 m below mean sea level) and replacing all internal clay sediment with rock fill. The floating transition ramp would require the construction of a fill structure to form an abutment in the shallow water. This fill structure would consist of engineered fill placed in layers to the desired final grade.

This site has the distinct advantage of deep water, and since it is on the west shore of Roberts Bay, adjacent to a steep cliff, it is well sheltered from the prevailing winds. It was however excluded as a preferred alternative for the Doris North Project, primarily due to its distance from the camp/mill site (approximately 9 km). The use of this site would required an additional 5 km of permanent all-weather road, and a major stream crossing, or alternatively summer storage with winter transport via a winter road.

2.3.3 East Shore Peninsula (Jetty Site #2)

Detailed bathymetry in Roberts Bay (see Section 3.2) suggests that there is a section of deep water immediately west of the peninsula jutting 700 m out into the Bay south of the main island (Figures 2 and 3). Barges could enter this section of the bay from west of the island and berth up to a 30 to 50 m long jetty.

Offshore geotechnical conditions were not evaluated in this zone, but from aerial photography and regional data (EBA 1997; SRK 2005a, b) the soil lithology is probably soft marine sediments overlying intact competent bedrock. The onshore terminus of this jetty would be on bedrock outcrop, which covers most of the peninsula. Although the creation of road access through the bedrock peninsula would require significant drilling and blasting, it would likely be cost effective, since the development of the project requires substantial volumes of quarried material.

The site was however not selected as a preferred alternative due to concerns about potential significant adverse environmental effects on aquatic life, specifically migrating Arctic Char which are known to spawn in Little Roberts Creek. MHBL was of the opinion that the narrow channel between the peninsula and island could cause conflict in the event that Char was moving towards the spawning area.

It should be noted that no specific studies were conducted to confirm if a jetty in this location would impact the Char; however, MHBL opted to err on the safe side.



2.3.4 Southern Roberts Bay Shoreline Site (Jetty Site #1 - Preferred Location)

The Bay bathymetry (see Section 3.2) indicated a section of deeper water leading up to the shallow shelf along the southern shoreline of Roberts Bay (Figures 2 and 3). This location suggested that constructing a 100 m long jetty would allow for the safe offloading of barges.

Shoreline geotechnical investigations (SRK 2005a) have confirmed the presence of ice-rich marine silt and clay permafrost between patches of exposed bedrock. In order to allow the use of this site, an all-weather road will have to lead from the jetty towards a lay-down area approximately 100 m inland from the shoreline (a self-imposed restriction set by MHBL).

Offshore geotechnical investigations (see Section 3.4) confirmed that the jetty will have to be constructed on deep soft marine sediments overlying bedrock, in shallow water.

Based on the evaluation of all the other alternative jetty locations, this site was selected as the preferred sealift offloading site for the Doris North Project. Although it is recognised that an approximately 100 m long jetty would have to be constructed on challenging foundation conditions, the proximity of the site to the camp/mill is advantageous and offers potential for cost saving. There are also no potential significant environmental effects associated with constructing the jetty at this location (see Section 3.4).



3 Investigations

3.1 Introduction

MHBL initiated a number of technical studies to obtain baseline data that can be used to design a jetty for the Doris North Project. These studies included confirming the feasibility of barges accessing the site, providing adequate bathymetry, evaluating potential shoreline processes, wind and wave heights etc., as well as confirming the jetty foundation conditions.

3.2 Barge Access

MHBL consulted with directly with NTCL on the feasibility of using the preferred jetty location as an offloading facility. A representative from NTCL personally inspected the site, reviewed ortho-photos, conducted an aerial reconnaissance of the site via helicopter, carried out a cursory bathymetric reconnaissance via small boat, and finally manoeuvred a tug into the area under consideration.

The findings of this consultation were documented in a Technical Memorandum (included as Appendix A) by MHBL, and confirmed that the site would be suitable as an offloading facility as seen from the perspective of the shipping company.

3.3 Bathymetry

Frontier Geosciences Inc. carried out an over water bathymetric survey at the southern extremity of Roberts Bay in September 2003 (Frontier Geosciences 2003, also included as Appendix B). The survey was completed with a marine depth sounder as recorded from a small boat. The depth sounder data was correlated with a GPS to accurately locate each data point.

The bathymetry (Figure 3) indicated the presence of an elongate, north-south trending channel defined generally by the 5 m water depth contour in the south, and water depths in excess of 30 m in the north. The channel was found to be relatively wide; however, at the southernmost point it narrows to approximately 150 m. A localized deeper water depression was also observed in the middle of the survey area and west of the main island in the northeast segment of the area. The area is bounded to the north, by a region of relatively shallow depths.

In the area of the jetty, water depths are shallow, in the order of 1 m, with a relatively steep drop off to 5 m depth at around 75 to 100 m offshore. Limited boat draft and boulder hazards in this shallow shelf precluded more detailed coverage of this area.

Subsequent to this bathymetric survey, SRK conducted a series of geotechnical investigations in the jetty location (Section 3.5). Measurements of water depth at the proposed jetty terminus by SRK engineers suggest that the water is shallower by approximately 1 m, than proposed by the



bathymetric survey by Frontier Geosciences. Should the measurements by SRK be accurate, it may offer optimization opportunities for the jetty construction, and therefore MHBL proposes to carry out an additional detailed bathymetric survey of the jetty location prior to proceeding with detailed design of the jetty (see also Section 5.4).

3.4 Shoreline Erosion Processes

A number of field investigations were completed by Golder Associates Ltd. (Golder) during the summer of 2004 to allow characterization of shoreline processes in Roberts Bay in the vicinity of the jetty (Golder 2005). These studies were an expansion of scoping level studies that were originally completed in June 2004 (Golder 2004). The field programmes included; (1) collection of wave height data, (2) collection of tidal data, (3) measurement of tidal currents, (4) characterization of shoreline substrate, and (5) wind measurement.

Using a numerical model, calibrated with the field data, it was concluded that the largest and most frequent waves at the jetty site come from the north, and the maximum waves are predicted to be 0.9 m in height.

The predominant force on long-shore transport of sediment in the foreshore zone of Roberts Bay was estimated to be wind waves during the short summer open water season.

The net transport of sediment is north to south along the west side of the Roberts Bay shoreline, and the area proposed for the jetty appears to be an area of low to zero long-shore transport.

Overall there is minimal material available for sediment transport in Roberts Bay. Cobbles and boulders characterize much of the shoreline, which are not transportable by the local waves. The bed of Roberts Bay, including shallow near shore areas, is comprised of marine clay. These clays appear to be mobilized during storm events, with subsequent deposition during calm periods.

It was concluded that sediment transport is an episodic process, with most transport occurring during summer months from the north. The mean wind speeds in the area are also too low to generate appreciable sediment transport.

Therefore, it was concluded that the presence of the jetty is not anticipated to cause significant potential adverse environmental effects on near- or long shore marine processes resulting in localized changes in sediment transport and deposition patterns.

3.5 Geotechnical Foundation Conditions

3.5.1 EBA (1997) Roberts Bay Port Site Geotechnical Investigation

EBA Engineering Consultants Inc. (EBA) carried out a geotechnical investigation in May 1997 (EBA 1997) to characterize onshore and offshore foundation conditions to develop preliminary



designs for a deep water dock along the western shore of Roberts Bay (see Figure 2 and Section 2.3.2 above).

The program consisted of six onshore geotechnical drill holes, four offshore geotechnical drill holes, eight offshore probe holes and 11 bathymetric check points. The onshore drill holes were completed in order to obtain geotechnical and permafrost data for preliminary design of foundation conditions for terminal facilities. Three 15 m thermistor strings were installed in three separate boreholes to provide ground temperature data.

The four offshore geotechnical drill holes provided lithology and soil samples of the ground conditions in an area where a sheet pile structure was considered to provide barge berth. The eight offshore probe holes provided data on the depth to seabed, depth to bedrock and lithology of the marine sediments for potential ship anchoring and mooring locations. The bathymetric check points provided depth to seabed along three lines extending east from the shoreline.

The onshore soils were found to be consistent with that observed during other later drilling programs (SRK 2005a). The soils are of marine origin and generally consist of a thin layer of organic peat overlying up to 5 m of silty clay of low plasticity with occasional sand laminae. A thin layer of sand and gravel underlies the silty clay and this rests on intact competent volcanic rock identified as basalt and rhyolite. Soil ice content was low to moderate. Soil pore water was saline, and although measured salinities indicated values greater than the salinity of seawater, the report concludes that the results may have been compromised by the brine used in the drilling fluid.

The offshore drill holes close to shore indicated a soil lithology consisting of silty clay of variable thickness (2 to 8 m) overlying competent bedrock of the same origin as onshore. In one hole a sand layer was found to underlie the silty clay. Laboratory measurements confirmed that the sediments have an undrained shear strength between 2 and 22 kPa, is very soft and compressible, with low plasticity.

Further offshore where water depths exceeded 50 m the lithology remains similar; however, the silty clay thickness increases to between 6 and 14 m.

Although these investigations are located a significant distance from the proposed jetty location (Figure 2), the general similarity of soil lithology that has been observed throughout the site (SRK 2005a, b) suggest that this data will be a useful indicator to support site specific jetty foundation data. Appendix C contains a summary of the pertinent geotechnical data on submarine sediments as extracted from these drill holes.

3.5.2 Jetty Foundation Drilling (SRK Phase I Investigation)

SRK completed a reconnaissance level geotechnical investigation in April 2004 (Appendix D) at the proposed jetty location (Figure 4). The intent of the drill program was to determine site specific information pertaining to the proposed alignment of the jetty.



Four drill holes were completed along the proposed centerline of the jetty (Figure 5), spaced approximately 25 m apart, extending out from the shoreline, to a maximum distance of approximately 100 m.

The investigation confirmed that the water depth at the jetty location varies between 0 to 5 m (Figure 6). Sea ice approximately 2 m thick develops in the winter and freezes to the bottom of the seabed for at least the first 55 m of the proposed approximately 100 m long jetty. The drilling results confirm sub-ocean permafrost to at least this location.

For the first 55 to 75 m from the shoreline, the jetty foundation consists of a 3 to 5 m thick layer of frozen marine silt and clay over 6 to 9 m of sand and gravel. The remainder of the jetty has deeper water and is underlain by unfrozen marine silt and clay, 8 to 12 m thick. The underlying basalt bedrock is intact and competent. Appendix C contains a summary of this data.

3.5.3 In-Situ Vane Shear Testing (SRK Phase II Investigation)

A second phase geotechnical foundation investigation to specifically measure the in-situ shear strength of the soft marine sediments at the proposed jetty location was conducted by SRK in April 2005 (Appendix E).

The testing consisted of six borings approximately 5 m deep using a Nilcon vane-shear apparatus. The six borings were all located at the terminus of the jetty where the proposed fill would be the maximum (Figure 5), and where drilling data has confirmed the sediment layer to be the thickest and thus potentially the most sensitive to excessive loading. At each boring location, vane shear tests were taken at 5 or 6 depths to determine a depth profile of shear strength.

Shear testing in these deeper marine sediments approximately 90 to 100 m from the shore confirmed that the upper 5 m of the marine sediments have peak shear strengths ranging between 14 and 28 kPa, with an average value of 21 kPa. Residual strengths ranged between 5 and 13 kPa with an average value of 9 kPa. Generally the strength was observed to increase with depth.



4 Conceptual Design Alternatives

4.1 Introduction

A number of alternative jetty designs were evaluated for the Doris North Project. Brief details of the conceptual alternatives are discussed in the following sections of this report. These alternatives were developed with the assistance and guidance of Westmar Consultants Inc. (Westmar), an engineering firm specializing in the design and construction of offshore infrastructure including large ports, docks and jetties.

4.2 Option 1: Continuous Rock Fill Jetty

The shallow water depths leading to the terminus of the jetty, suggest that a simple continuous rock fill jetty, 1 to 3 m thick would be a practical design alternative (Figures 7 and 8). The soft unfrozen marine sediments approximately 50 to 100 m offshore has low bearing capacity, and therefore special construction considerations have to be considered. Pre-loading would be one method of overcoming the bearing capacity problem. This would be done by initially placing approximately half the fill thickness, after which some time for settlement is allowed. Placement of the remainder of the fill would follow at an appropriate time. Pre-loading could be done over a few summer construction seasons, or alternatively the first fill could be placed in the winter (through the sea ice), with the final fill following six months later during the open water season.

The bearing capacity concerns can also be overcome by constructing the fill in layers, with each layer supported by geosynthetics (i.e. geogrids and geotextiles). These geosynthetics does not per se increase the bearing capacity, but prevents the pad from spreading laterally, as well as precluding the other possible failure mechanisms of a pad constructed on low strength ground. This technique of reinforcing pads is commonly used, as documented in Koerner (2005).

Spreading construction of the jetty over a number of seasons, in order to allow for preloading of the foundation would not be an acceptable approach to MHBL, and would result in the exclusion of this design alternative, since the proposed MHBL construction and production schedule for the Doris North Project would be compromised; however, preloading during the winter, with the remainder of the fill being placed during the immediately following summer, would be an acceptable approach.

Notwithstanding the possibility of preloading, the inclusion of geosynthetics in the design would be paramount to its acceptance, since that would ensure constructability. It is however likely, that even with the inclusion of geosynthetics, the jetty will undergo differential settlement and annual maintenance of the jetty will be required.

Preliminary cost estimates for this design alternative suggest, that construction would be less than $0.3 million. This cost is considered to be all inclusive, since construction can be carried out with a conventional construction fleet, by a suitably qualified and experienced earthworks contractor.



4.3 Option 2: Rock Fill Jetty with Arch Culverts

Prior to completion of the Golder (2005) shoreline processes study, one of the potential adverse environmental effects associated with the continuous rock fill jetty (Option 1) was that the presence of an impassable object jutting out 100 m from the shoreline may impede the passage of fish, and that it may effect near- and long-shore erosion processes.

In order to partially mitigate against this potential adverse effect, a modified continuous rock fill jetty was presented which includes a series of large diameter steel culverts (Figures 9 and 10). In concept these culverts should achieve the goal of allowing fish to pass through the jetty; however, the feasibility of keeping these culverts operational as differential settlement takes place may be problematic.

The cost of including the culverts would not be significantly more than for the continuous rock fill jetty; however, the cost of maintenance would be substantially increased if culverts had to be replaced over time.

Due to the marginal benefits that the culverts offer, the increased maintenance risk, and the fact that the presence of a rock fill jetty has been shown to not have any potential adverse environmental effect, this jetty design alternative was not given further consideration.

4.4 Option 3: Rock Fill Buttressed Jetty with Prefabricated Decks

In an attempt to minimize the amount of rock fill required, and to reduce the jetty footprint an alternative design was considered which entailed construction of rock fill islands or buttresses. These buttresses would be linked with prefabricated steel bridge decks or possibly pre-cast concrete decks (Figures 11 and 12).

Summer construction of this type of design would require specialized working barges, which would be cost prohibitive. Alternatively, winter construction would have to be carried out through the sea ice, which would once again pose significant challenges to ensure ice-free working conditions.

Preliminary cost estimates suggest that this type of structure (under winter construction conditions) would be approximately twice as expensive as a continuous rock fill jetty. This cost however has significant uncertainties associated with potential technical complications which may substantially increase the cost.

Finally, concerns with differential settlement of the buttresses and the associated deformation of the bridge deck or pre-cast slabs, has resulted in the exclusion of this as a viable alternative jetty design.



4.5 Option 4: Conventional Piled Jetty with Prefabricated Decks

An alternative jetty design to Option 3, which keeps the benefits of a reduced footprint but mitigate against the potential instability of the rock fill buttresses, would be to support the prefabricated bridge decks or pre-cast concrete slabs with piled foundations (Figures 13 and 14).

Pile supported wharf structures have been successfully used in Arctic conditions. Generally the arrangement would consist of steel pipe piles, cast in-place concrete pile caps and the prefabricated steel bridge deck or pre-cast concrete slab on top.

The pile supported structure will be subject to berthing loads from the barges, as well as significant sea ice pressures. Consequently, the piles will require socketing into the bedrock, and possible protection through placement of a rock fill shell around each pile. Rock socketing increases the cost of the structure, due to the need for specialized equipment, and the increased effort also substantially increases the construction time.

Preliminary cost estimates suggest that this jetty design alternative would be in excess of $2 million, excluding the cost of shipping specialized pile driving equipment to site. This jetty design alternative was subsequently excluded from further consideration.

4.6 Option 5: Cellular Sheet Pile Jetty

A sheet pile cell is a gravity type structure capable of withstanding high lateral loads from vessel or ice impact without sustaining damage.

A jetty design which includes the use of two 23 m diameter sheet pile cells is presented in Figures 15 and 16. These cells would be placed on the soft marine sediments approximately 50 to 100 m offshore to mitigate against the differential settlement that a continuous rock fill jetty (Option 1) would be subjected to. These sheet pile cells would be linked to the shoreline with a 40 m long continuous rock fill jetty which is founded on permafrost.

The sheet pile cells would have to be founded in bedrock, and the soft marine sediments within them would have to be replaced by rock fill. This would require the use of specialized equipment, and if permafrost is encountered, the sheet pile cells may not even penetrate the substrate.

Preliminary cost estimates for this jetty design were estimated at $7.4 million, excluding (1) transportation of specialized equipment and supplies from Hay River, NT to Roberts Bay, (2) cost of rock fill, and (3) fuel for construction equipment. An optimization was considered to the design whereby only a single sheet pile cell was to be used; however the cost of this alternative still came in at approximately $5 million.

Based on the cost of this design, it has been excluded as a viable alternative.



4.7 Option 6: Rock Fill Jetty on In-Situ Frozen Ground

The presence of submarine permafrost along a portion of the jetty alignment suggest that possibly the entire jetty foundation could be artificially frozen, to provide a stable foundation that would preclude differential settlement.

The layout would consist of placing a continuous rock fill jetty (similar to Option 1) on the frozen seabed. In advance of placement of the rock fill, the silt and clay stratum within the footprint of the jetty would be frozen using mechanical refrigeration. Mechanical refrigeration of this stratum would be achieved by installing a network of thermosyphons below the seabed using directional drilling techniques. The thermosyphons would then be connected to a refrigeration plant system which provides the means to freeze the soil.

Based on discussions with a ground-freezing contractor, installation of the thermosyphons would begin in the spring (May), with completion in the summer (July). Upon completion of the refrigeration system, it has been estimated that the silt and clay stratum would require 12 months in order to completely freeze. Consequently, placement of rock fill on the frozen seabed to form the jetty cannot begin until one year after the refrigeration system has been operational. Based on this schedule, the jetty would be ready for service two years following the start of ground freezing.

An order of magnitude cost estimate has been provided by a ground freezing contractor (Arctic Foundations of Canada Inc.) The supply and installation of the refrigeration system is estimated at $2.5 million and excludes (1) the supply of power to the refrigeration plants, (2) transportation of equipment from Hay River, NT to Roberts Bay, and (3) the cost of rock fill.

Based on the cost of installing the ground freezing system and the prolonged schedule to complete the jetty, ground freezing is not recommended at this site.

4.8 Option 7: Bay Dredging & Rock Fill Jetty

At the site of the jetty, the inshore seabed grade is shallow. In order to achieve water depths sufficient for clearance of the loaded draft of the barges, an arrangement comprised of dredging the seabed towards shore and placing a small rock fill jetty to the edge of the dredge pocket has been investigated (Figures 17 and 18).

The barges would be orientated longitudinal to the jetty in order to minimize dredge volume. The width of the dredge pocket would include an allowance on either side of the barge for a tug boat. The depth of the dredge pocket would provide an under keel clearance of 1 m for the loaded barge at lower low water level (LLWL). At the inshore side, below the footprint of the rock fill jetty, dredging would extend down to the sand and gravel layer to remove the silt and clay stratum. The dredged material would be side cast to locations within the vicinity of the site, subject to approval from regulatory authorities. This material may in fact have to be relocated to deep water, which would further increase costs.



The jetty itself would comprise a continuous rock fill structure founded on permafrost, similar to the jetty described for Option 1.

A preliminary cost estimate suggest that this design will cost approximately $1.9 million, excluding (1) transportation of equipment from Hay River, NT to Roberts Bay, (2) cost of rock fill, and (3) cost of fuel.

Although no baseline data is available to confirm what the potential adverse environmental effects of dredging would be, it is conceivable that these effects may be significant, and that fact combined with the projected capital cost, resulted in the rejection of this alternative.



5 Preferred Design

5.1 Selection of Preferred Design

As discussed in Section 4 of this report, all of the proposed alternative jetty designs were judged to be inappropriate for the Doris North Project, with the exception of the continuous rock fill jetty (Option 1).

The most significant technical issue associated with the continuous rock fill jetty is the low strength characteristics of the marine sediments, that will result in differential settlement of the jetty, and that may require the inclusion of geosynthetics to help support the structure. Notwithstanding the inclusion of the geosynthetics, and taking into account annual maintenance, the continuous rock fill jetty was deemed to be feasible, and preliminary cost estimates suggests that it would be economically justified for the Project.

The presence of an approximately 100 m long continuous rock fill jetty in Roberts Bay will have a potential adverse environmental effect; however, shoreline process studies have confirmed that these effects will not be significant (Golder 2005).

Therefore, the continuous rock fill jetty was selected as the preferred jetty design, and the following sections of this report documents the details of the proposed preliminary design.

5.2 Design Criteria

Design criteria for the jetty are summarized in Table 1. It should be noted that the jetty will only be used for a period of two to three weeks during the late summer (August) every year that it is in operation. Furthermore, for the Doris North Project, the jetty is only expected to be used for a period of four years. This includes two years of mining and two years of active decommissioning. Subsequent to active decommissioning the jetty will no longer be required, since further annual re-supply volumes are expected to be small and will be done via sealift to the existing barge landing site (see Section 2.3.1).

MHBL therefore proposes to design the jetty with a minimal design life, and accept the risks and consequences that this design criteria has. The risks include damage to the jetty due to large waves, storm surges and sea ice. Furthermore, annual settlement and frost heave could result in damage to jetty. MHBL will however implement the necessary maintenance actions to ensure safe operation of the jetty when the time requires (see Section 5.6). The physical consequences of damage to the jetty include addition of construction rock and an increased jetty footprint. MHBL acknowledges these facts and have made allowance for these consequences (see Section 5.3). Operational consequences for these damages include delays to the offloading of the barges, with associated increased operational costs for the mine.



Table 1: Summary of Jetty Design Criteria

Design Component Design Criteria

Service Life Approximately 4 years (two years of mine life + two years of active mine closure; traditional barge landing and winter road, or winter airstrip will be used for the post closure phase)

Vessels

Barge NT 1500 Series: 1,886 tonne dead weight; 76.2 m LOA; 17.1 m Beam; 0.97 m minimum freeboard; 3.05 m Draft Barge NT 2000 Series (Future): 3,870 tonne dead weight; 90 m LOA; 18.9 m Beam; 1.10 m minimum freeboard; 2.90 m Draft

Vehicles

Integrated Tool Carrier (TC-28) = 11,412 kg Wheel Loader Komatsu WA500-3; operating weight = 31,000 kg (Supplied by NTCL for off-loading only (Provisions for unloading mill modules for the mine at the jetty have not been included; these modules will be offloaded at the existing barge landing site)

Tides

Tide levels in Melville Sound (north of the site), as listed below, are taken from Canadian Hydro-graphic Service Chart 7780. EHWL and ELWL are based on tides at Cambridge Bay. Tides are referenced to local Chart datum. Extreme High Water Level (EHWL) = 0.5 m Higher High Water Level, Large Tide (HHWL) = 0.2 m Higher High Water Level, Mean Tide = 0.2 m Mean Water Level (MWL) = 0.0 m Lower Low Water Level, mean Tide = -0.1 m Lower Low Water Level, Large Tide (LLWL) = -0.1 m Extreme Low Water Level (ELWL) = -0.3 m This tide data is consistent with site specific data reported in Golder (2005) and Frontier Geosciences (2003).

Jetty Working Platform

Minimum Water Depth: Established to provide a minimum of 0.5 m keel offset for the Series 1500 barge below LLWL. Deck Height: Established to provide 1.0 m of freeboard above the HHWL.

Roadway Width 6 m

Barge Ramp

Barges are supplied with a 25 ft long ramp to span between the barge and the jetty structure. The maximum recommended grade of the ramp is 6%. Considering the freeboard range of the barges (fully loaded to empty), a permanent ramp at the jetty may be required. This will not affect the overall jetty footprint and well be fully evaluated at the final design stage.

Jetty Terminus Work Area

NTCL requires only 6 m of work space to offload the barges; however, they prefer a berthing face of at least 20 m wide. Barge unloading can be from barges orientated laterally or longitudinally to the jetty.

Wave Conditions Largest waves from North, with maximum wave height = 0.9 m Maximum sustained storm surge = 1.0 m.

Geotechnical Parameters

Existing Seabed: Unfrozen and frozen Silt and Clay; Saturated unit weight = 18 kN/m3; Peak Shear Strength = 15 kPa Existing Seabed: Frozen Sand and Gravel; Saturated unit weight = 18 kN/m3 Engineered Fill: Rock fill; Unit weight = 19.62 kN/m3

Engineered Fill

Bulk Fill, Sub Grade: Run-of-quarry rock (< 1,000 mm size fraction) Transition Zone, Select Grade; Crushed and screened quarry rock (< 200 mm size fraction) Surfacing Grade; Crushed and screened quarry rock (< 38 mm size fraction)



MHBL will be the only official user of the jetty. MHBL does however acknowledge that local communities may make use of the jetty whilst it is in operation. MHBL would not restrict access to the jetty unless, MHBL is of the opinion that the jetty is not safe to use. In such instances MHBL reserves the right to restrict access to the jetty.

5.3 Design Detail

Design details for the jetty are provided in Figures 19 through 21. Appendix F contains details of the preliminary engineering design of the jetty. The total footprint of the jetty is estimated at approximately 1,800 m2 (this is the base footprint, i.e. the surface area covered by the pad). The total amount of rock fill is estimated at approximately 5,600 m3 (11,600 tonnes). For planning purposes, and arbitrary allowance of 50% increase of this footprint and rock fill volume has been made (i.e. increase in footprint of 900 m2 and volume of 2,800 m3). This allowance caters for unforeseen settlement and slumping.

Discounting the required overlap, the surface area coverage of the primary geogrid layer (based on a single layer) is estimated at approximately 3,300 m2. This footprint exceeds the jetty footprint to ensure that all rock fill will be on the primary geogrid layer. Typical specifications of the geogrid are included as Appendix G.

5.4 Optimization Opportunities

Based on a fully laden NT Series 1500 barge draft of 3.05 m, and measuring from the LLWL, with a keel offset of 0.5 m, the minimum water depth at the jetty terminus needs to be approximately 3.6 m. The proposed preliminary jetty design shows a minimum water depth at the jetty terminus of just over 5 m, which effectively allows for a keel offset of just under 1.3 m (based on the bathymetry measured by Frontier Geosciences, see Section 3.3). As discussed in Section 3.3, there is some uncertainty associated with the bathymetry data, and therefore the preliminary jetty design has been based on conservative assumptions.

Prior to conducting the detailed jetty design, MHBL will carry out a detailed bathymetric survey of the jetty area. If in fact, there is sufficient water depth at the jetty terminus, as is suggested by the current bathymetric data, the jetty terminus will be moved closer inshore to coincide with a minimum water depth of 3.7 m. This will result in the total jetty length reducing to 60 m, with a subsequent reduction in footprint of 1,200 m2 and 50% less rock fill would be required (Figures 22 and 23). Under this scenario, the bulk of the jetty will be on more stable frozen marine sediments, and subsequently the construction and maintenance issues will be significantly improved.

As discussed in Appendix F, the size of the jetty terminus directly impacts the pressure that the jetty exerts on its foundation. Prior to conducting the detailed jetty design, MHBL will conduct further foundation testing at the jetty terminus, to confirm the optimal size of the jetty terminus, since it may be beneficial to reduce its size. Such a reduction would however result in a smaller jetty footprint and a smaller amount of construction rock being used.



Finally, a decision on the need to preload the jetty will be made after completion of further geotechnical testing at the jetty terminus. Since all the potential optimizations that will be considered at the detailed design stage will lead to a smaller jetty, with a reduced footprint and will require less construction rock, the preferred design tabled at this time is conservative and appropriate.

5.5 Construction

Construction of the continuous rock fill jetty will be carried out during the summer open water season in Roberts Bay. Construction will be suspended for a two week period in late July to not interfere with large numbers of capelin that move through the area during migration to their spawning grounds.

Construction will consist of end-dumping the engineered fill (quarry rock) from the shoreline towards the terminus of the jetty approximately 100 m offshore. After a few dump loads have been placed, a loader or dozer will be used to flatten the advancing front such that equipment can continue to end dump. In deeper water (more than 2 m depth) the initial rock fill be manually placed using an extended boom excavator. This will reduce the impact surcharge on the soft marine sediments and allow for more controlled placement of the fill.

Prior to placing any rock fill, a series of geosynthetics (at least two layers of geogrid) will be placed on the seabed. These geogrids will extend at least 5 m beyond the outermost edge of the final jetty footprint and will be at least 5 m ahead of the current fill being placed. The geogrid overlap will not be less than 2 m. The placement of the geogrid will be done by Arctic divers.

After completion of the bulk fill to the terminus of the jetty, the transition zone and jetty surfacing grade material will be placed once again moving from the shore advancing out towards the jetty terminus.

At the outset of the construction season the entire perimeter of the jetty construction zone will be encircled by a silt curtain, to effectively mitigate against the release of suspended solids as material is dumped onto the soft marine sediments.

As discussed previously, further geotechnical investigation in the jetty terminus area will confirm whether preloading of the jetty fill in areas that exceed 3 m in fill would be advantageous. If this is recommended, the first lift will be constructed during the winter, though the sea ice.

The jetty will be constructed from clean rock located in Quarry #1 (Figure 1). This rock has been geochemically tested to confirm that there would be no adverse environmental effects associated with its use (AMEC 2003). The quarry rock will not be washed prior to placement. Since there will be some blast residue on this rock when it is placed in Roberts Bay, SRK modelled the water quality in the Bay to confirm that there would be no adverse environmental effects as a result of this practice. The results of this calculation are documented as an Appendix to SRK (2005c).



5.6 Maintenance

It is expected that the jetty will continue to undergo differential settlement over its lifetime, although the rate of settlement will likely exponentially decrease as time progresses, consistent with consolidation theory. Considering the fact that the jetty will only be in use for two to three weeks in any year, this differential settlement can be managed with a program of annual maintenance.

Annual maintenance will consist of adding rock fill to the jetty surface, such that the traffic grade would be passable for barge off-loading equipment. Furthermore, the design freeboard of 1 m above the HHWL would be maintained. For planning purposes it has been assumed that the jetty surface would require an additional 50 cm of rock fill every year during its life. This means 350 m3 of additional construction rock will be required every year for four years.

During initial construction, a stockpile of additional crushed rock, specifically for jetty maintenance will be left in Quarry #1 (Figure 1). Every year this fill, as required, will be added to the jetty traffic surface by end-dumping and grading. If substantial fill is anticipated in deeper water, and there would be potential for large boulders to run down the side slopes and disturb sediments on the seabed, silt curtains will be deployed prior to undertaking any maintenance work. This will be to effectively mitigate against any possible increased turbidity in the Bay.

The barge operator, NTCL, requires that MHBL carry out a bathymetric survey of the channel leading up to the jetty every year prior to barge arrival. MHBL will extend this bathymetric survey to include the jetty footprint, such that accurate records of the jetty can be kept. This data will furthermore provide data with respect to the potential effect of the jetty on shoreline processes.

5.7 Decommissioning

The jetty will remain in operation for two years of active decommissioning after mining ceases. At that time all mooring hardware will be dismantled and removed from the jetty. The jetty will then be partially removed. Partial removal will entail lowering the jetty surface to 30 cm below LLWL. This will be achieved by pushing the excess material to either side of the jetty, without actually picking up and removing the material. This will result in an increase in the base footprint of the jetty.

Complete removal is not possible without removal of a substantial volume of natural marine sediments. This is due to the fact that the jetty will continue to settle into the marine sediments over its lifetime.

This preliminary jetty design is specifically for the two year Doris North Project. Should further exploration prove a larger project in the Hope Bay Belt, MHBL may decide to change the design of the jetty to accommodate a larger scale and longer duration project. Such a change will naturally result in a revised environmental review process; however, it should be noted that the jetty design as proposed in this report, may become the foundation of a larger scale jetty at this location.



This report, Preliminary Jetty Design, Doris North Project, Hope Bay, Nunavut, Canada, has been prepared by SRK Consulting (Canada) Inc.

Prepared by:

Maritz Rykaart, Ph.D., P.Eng. Senior Engineer

Reviewed by:

Cam Scott, P.Eng. Principal



6 References AMEC Earth & Environmental Ltd. 2003. ARD and Metal Leaching Characterization Studies in 2003, Doris North Project, November.

EBA Engineering Consultants. 1997. Boston Gold Project Geotechnical Investigation Proposed Roberts Bay Port. Report Submitted to BHP World Minerals, October.

Golder Associates Ltd., 2004. Supplementary Information on: Potential Impacts on Shorelines due to Construction of Jetty at Roberts Bay Miramar Doris North Project. Golder Associates Ltd. Report No. 04-1373-002.

Golder Associates Ltd., 2005. Potential impacts on shoreline due to construction of a jetty at Roberts Bay Miramar Doris North Project. Golder Associates Ltd. Report No. 04-1373-009-4100: 29 p. + 6 app.

Frontier Geosciences Inc., 2003. Report on Marine Bathymetry Survey, Proposed Roberts Bay Docking Facilities, Cambridge Bay Area, Nunavut. Report submitted to SRK Consulting, September 2003.

Koerner, R.M., 2005. Designing with Geosynthetics, Fifth Edition. Pearson Prentice Hall, N.J., 796 p.

SRK Consulting (Canada) Inc., 2005a. Preliminary Surface Infrastructure Design, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October, 2005.

SRK Consulting (Canada) Inc., 2005b. Preliminary Tailings Dam Design, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005.

SRK Consulting (Canada) Inc., 2005c. Water Quality Model, Doris North Project, Hope Bay, Nunavut, Canada. Report submitted to Miramar Hope Bay Limited, October 2005.

Figures

Roberts Bay Bathymetry(per Frontier Geosciences Inc.)

APPROVED: FIGURE:

3

DORIS NORTH PROJECTPreliminary Jetty Design

PROJECT:1CM014.006

DATE:Sept. 2005

MIRAMAR HOPE BAY LIMITEDEMR

File Ref: Fig 3_Prelim Jetty_Roberts B_20050526.ppt

[INCORRECTLY IDENTIFIED BY FRONTIER GEOSCIENCES]

CORRECT LOCATION OF PROPOSED DOCK

Appendix A MHBL Technical Memorandum

C:\Documents and Settings\mrykaart\My Documents\Barge Landing Investigation (Ted).doc 5/25/2005 6:21:11 PM

MIRAMAR HOPE BAY LTD.

311 West First Street, North Vancouver, B.C. V7M 1B5 Telephone: 604-985-2572 fax 604-980-0731

M E M O R A N D U M TO: B. Labadie Cc: FROM: E. Mahoney SUBJECT: Investigation of Barge Landing Area DATE: Sept. 15, 2002 Executive Summary Investigation was done into the suitability of the area proposed in the Scoping Study for a barge landing area with the assistance of Steven McKnight, master of the MV Edgar Kotokak, the tug delivering supplies to Roberts Bay. The presently proposed barge landing area would be suitable for use, provided that a causeway roughly 100m long were constructed with a landing area on the end of it. The MV Edgar Kotokak did a sea trial approach to this landing area to ensure that there would be sufficient manoevering room. As the causeway would be in water depths averaging 1m or less, construction costs of this should be manageable. Additional recommended work should include:

Actual measurements of tidal variation in Roberts Bay More detailed bathymetry in the southern area of Roberts Bay (several days in a

small boat equipped with a depth sounder and GPS). Investigation into the permitting issues related to construction of a causeway

from the shore

Details Investigation was done into the suitability of the area proposed in the Scoping Study for a barge landing area. Concerns included the shallow nature of the water close to shore and the room to manoever the barges and tug in somewhat restricted waters. The proposed site would be the optimal one to use if possible, as it would require minimal construction of all-weather road. Currently Proposed Site

2

The currently used barge offloading site is a very good location as there is deep water just off the shore, and it is in an area where Roberts Bay is quite open. In order to use this location during the mine operation (provided an all weather road is to be constructed) 2 km of all weather road and a bridge crossing of a stream would have to be constructed. The costs of this additional construction make it unattractive. Water Level Variations Roberts Bay has very low tidal variation, likely less than 0.5m, and it has been reported that a strong NW wind can increase water depths by 0.5m and a strong SE wind can decrease it a similar amount. Vessels Currently Used The tugs and barges employed by NTCL are shallow draft vessals, with the tugs drawing roughly 2m of water. A fully loaded series 1500 barge, carrying 1,500 tonnes of deck cargo and 1 million litres of fuel will draw 2m of water as well. A series 1500 barge is 250 ft. long and 55 feet wide. The MV Edgar Kotokak arrived at Roberts Bay on Sept. 15th, under the command of Steven McKnight. It was pulling a series 1500 barge, with significant deck cargo, but no fuel in its holds. It was pushed nose into the beach at the currently used barge landing site. The nose of the barge grounded in 1m of water and forklifts began to offload cargo. NTCL Assistance Mr. Gordon Norberg, of NTCL had previously informed us that the master of the tug which delivered supplies to Roberts Bay this year would be able to inform us of the suitability of a proposed landing site for their use. I discussed the potential offloading site, and a few alternatives, with Mr. McKnight, and we reviewed ortho photos of the area, topo maps, and the government navigation chart for Roberts Bay. We flew the area in a helicopter, looking at possible sites, then scouted it in an aluminum runabout. Mr. McKnight used a sounding pole from the runabout to check depths near shore in several locations. As a final check, the MV Edgar Kotokak disengaged from the barge, and was piloted in to the southern end of Roberts Bay to determine if there was sufficient manoevering room in that somewhat restricted area. Information Resulting from Investigation One thing that was apparent from all of this data, is that near the shore of the southern area of Roberts Bay the water is very shallow and the bottom slopes gently for a distance out to where there is a drop-off. On the accompanying air photo there is a very noticeable change in color in the water where this drop-off occurs. From the soundings taken, it appears that the water depth at the edge of this drop-off is 1.0 and 1.5m. It is unlikely that any barge could get much closer to shore than the edge of the drop-off. An examination of the southern area of Roberts Bay was done to see if there was a location more suitable than that proposed here, or where the required causeway could be shortened. It was concluded that the best location is that currently proposed.

3

Design Considerations for Causeway

Any causeway constructed would need to be wide enough for equipment to travel safely over in unloading the barge.

Bollards to attach the barge to, or pre-set anchor points on shore would need to be present.

It would be best if the unloading area at the end of the causeway were designed to allow for a barge to pull alongside. This would require a length of approximately 50 to 75 ft. (15 to 23m).

C:\Documents and Settings\mrykaart\My Documents\Barge Landing Investigation (Ted).doc 5/25/2005 6:21:11 PM

CausewayNot Suitable

Tank Farm LaydownArea

Roberts BayProposed Barge Landing CausewayLocation

Appendix B Roberts Bay Bathymetry Report

(Frontier Geosciences 2003)

STEFFEN, ROBERTSON & KIRSTEN (CANADA) INC.

REPORT ON

MARINE BATHYMETRY SURVEY

PROPOSED ROBERTS BAY DOCKING FACILITIES

CAMBRIDGE BAY AREA, NUNAVUT

by

Russell A. Hillman, P.Eng.

PROJECT FGI-727September, 2003______________________________________________________________

Frontier Geosciences Inc. 237 St. Georges Avenue, North Vancouver, B.C., Canada V7L 4T4 Tel: 604.987.3037 Fax: 604.984.3074

CONTENTS

64. SUMMARY

5 3.2 Discussion5 3.1 General53. GEOPHYSICAL RESULTS

4 2.2 Survey Procedure3 2.1 Equipment32. THE MARINE BATHYMETRY SURVEY

11. INTRODUCTIONpage

ILLUSTRATIONS

AppendixBathymetry Contour PlanFigure 2Page 2Survey Location PlanFigure 1

location

(i)

Frontier Geosciences Inc.

1. INTRODUCTION

In the period September 8 to September 13, 2003, Frontier Geosciences Inc. carried out anoverwater bathymetric survey for Steffen, Robertson and Kirsten (Canada) Inc., at RobertsBay, Nunavut. A Survey Location Plan of the area is shown at an approximate scale of1:5,000,000 in Figure 1. The investigation was carried out to determine water depths in anarea proposed for docking facilities.

The survey area is located at the southern extremity of Roberts Bay. The marinebathymetry survey covered an area approximately 2.4 km north-south by approximately 1km east-west.

1


2KILOMETRES

APPROXIMATE SCALE1:5,000,000

SRK CONSULTINGROBERTS BAY, NUNAVUT

HYDROGRAPHIC SURVEY

FRONTIER GEOSCIENCES INC.

SURVEY LOCATION PLAN

DATE: SEPT. 2003 FIG. 1

NORTHWESTTERRITORIES

NUNAVUTYUKON

SITELOCATION

0 50 100 150 200

115W

110W 105W100

60N

ARCTICCIRCLE

65N

2. THE MARINE BATHYMETRY SURVEY

2.1 Equipment

The overwater bathymetric survey was completed with a Marinetek, PCS-200 sounder. Thesystem was calibrated with respect to water temperature and water salinity and used abroadband output with a 200 kHz centre frequency. Power for the field computer andMarinetek Sounder was provided by a portable, 120 volt, AC generator set. The work wascarried out with a local, six metre, Lund aluminum survey boat powered by an outboardmotor.

Tidal fluctuations during the survey were monitored by a tide pole placed at low water, inthe southeast corner of the survey area. The tide pole location was surveyed in from acontrol point (SAS 35) established by the surveyor. This control point located at7,563,703.47N, 432,943.85E, is at an elevation of 14.18 m. The base of the tide pole wasdetermined to be at an elevation of -0.1 m. In the course of the survey, the tide pole waschecked two to three times a day with water level fluctuations noted to vary from -0.1 m to0.3 m. These increases in water level were subtracted from the data, thus correcting the datato the -0.1 m elevation at the base of the tide pole.

The GPS system utilised in the survey was a high resolution, DGPS (Differential GlobalPositioning System) Max. Differential GPS uses two receivers to cancel out atmosphericerrors and Selective Availability (SA). The additional receiver is placed at a knownlocation and makes the same measurements as the roving receiver. The base receivercompares its readings from its known position to that of satellites and creates a differencebetween the two. This difference is made available to the roving receiver as differentialcorrection information. This correctional information allows the roving receiver tocalculate its true location. Information for receiver locations and corrections was providedby the Omnistar system.

3


2.2 Survey Procedure

The bathymetric transducer was placed in the water at a depth of 0.15 metres on thestarboard side, 1 metre forward of the transom. The transducer location was carefullydetermined to facilitate the best operating environment for the transmission and reception ofsound pulses. In operation, the source transducer pulsed twice every second with asounding frequency of 200 KHz. The pulses emitted from the transducer were reflected bythe sea bottom, then digitally recorded and visually reviewed in real time on the highresolution display of the notebook computer. The digital record of the reflected signal wasstored in the notebook hard drive and played back to interpret the water depth.

The bathymetric data was correlated with the GPS data to accurately plot each pulseposition to be contoured for final data presentation. The bathymetry plan used thepositioning datum of NAD83 in UTM grid coordinates.

4


3. GEOPHYSICAL RESULTS

3.1 General

The results of the overwater bathymetric survey are shown in colour contour format at ascale of 1:7,500 in Figure 2. The bathymetry data was reduced to local datum, which wasthe base of a tide pole located at low water in the southeast corner of the survey area.

3.2 Discussion

The bathymetry data indicates the presence of an elongate, north-south trending channeldefined generally by the 5 m contour in the south and water depths in excess of 30 m, to thenorth. The channel is quite broad to the north but narrows to a width of about 150 m in thesouth. A localised, deeper water depression is also evident in the middle of the survey areaand west of the island in the northeast segment of the area. This area is bounded to thenorth however, by a region of relatively shallow water depths.

In the area of the proposed dock structure, water depths are shallow and are of the order of1 metre. Limited boat draft and numerous boulder hazards limited more detailed coverageof this area. Water depths of 2 metres are extant about 150 m northwest of the shoreline, atthe proposed dock location.

5


4. SUMMARY

An overwater bathymetry survey was carried out over a segment of Roberts Bay inNunavut. The survey area is the site of a proposed docking structure and approaches forocean-going vessels.

The information in this report is based upon acoustic measurements and field proceduresand our interpretation of the data. The results are interpretive in nature and are consideredto be a reasonably accurate presentation of the ocean bottom configuration within the limitsof the overwater bathymetry method.

For: Frontier Geosciences Inc.

Russell A. Hillman, P.Eng.

6


FIG. 2SCALE 1:7,500DATE: SEPT. 2003

FRONTIER GEOSCIENCES INC.

BATHYMETRY CONTOUR PLAN

HYDROGRAPHIC SURVEY

ROBERTS BAY, NUNAVUTSRK CONSULTING

METRES

431500E 431600E 431700E 431800E 431900E 432000E 432100E 432200E 432300E 432400E 432500E 432600E 432700E 432800E7563200N

7563300N

7563400N

7563500N

7563600N

7563700N

7563800N

7563900N

7564000N

7564100N

7564200N

7564300N

7564400N

7564500N

7564600N

7564700N

7564800N

7564900N

7565000N

7565100N

7565200N

7565300N

7565400N

7565500N

7565600N

0 100 200 300 400

0.0 1.9 3.8 5.7 7.7 9.6 12.6 17.1 23.0

DEPTH (m)

INSTRUMENT: MARINETEK PCS-200

DATUM: NAD83 UTM ZONE 13

NOTE: SHORELINE APPROXIMATE

APPROXIMATELOCATION OF

PROPOSED DOCK

ISLAND

Appendix C Summary of Roberts Bay Geotechnical Properties

UU Triaxial (kPa)

Vane (kPa)

SRK45 15-16.4 m CL 34.8 42 24 18 94.5 49 0.37SRK46 4.7 - 6.2 m CL 56.8 39 22 17 94.8 43 0.40SRK47 2.1 - 3.6 m CL 37.2 34 18 16 93.7 27 0.59

SRK49 14.1 - 17.1 m CL 58.6 38 22 16 96.4 39 0.41SRK49 5.1 - 8.1 m CL 32.6 22 15 7 76.7 20 0.35

EBA BH-12 2.44 - 2.59 m CL 47.3 40.5 22 18.5 44.2 39.8 16 0 84 35 0.53EBA BH-15 3.96 - 4.57 m CL 67.5 41 18 23 52.5 43.2 4.3 0 95.7 43 0.53 1.8 14 5.5EBA BH-18 4.27 - 4.57 m CL 43 42 20 22 54.8 38.6 6.6 0 93.4 45 0.49

EBA BH-19 0 - 0.61 m CL 34.4 26 14 12 61.5 34.4 3 1.1 95.9 49 0.24 1.82 8.5 5EBA BH-28 3.81 - 4.42 m CL 40.8 30 16 14 46.4 29 23.4 1.2 75.4 32 0.44EBA BH-29 2.59 - 2.74 m CL 63.3 43 25 18 46.8 44.6 8.6 0 91.4 37 0.49

EBA BH-15 3.05 - 3.2 m CH 74.8 52.5 29 23.5 56.1 41 2.9 0 97.1 41 0.57EBA BH-26 3.05 - 3.66 m CH 70 56 23 33 17.5 47.3 35.2 0 64.8 11 3.00 1.78 3

EBA BH-11 0.91-1.07 m CL-ML 26 21 14 7 28 26.5 45.5 0 54.5 22 0.32

SRK46 12.3 - 13.8 m SP 20 np np np 7.7 0 npEBA BH-24 6.10 - 6.86 m SP 26.4 11.1 6 82.9 0 17.1 9EBA BH-28 9.91 - 10.52 m SP 28.4 84.9 0.1 15

EBA BH-18 0 - 0.61 m 31.5 1.86 27.5 12EBA BH-24 2.74 - 3.35 m 31.6 1.25 2EBA BH-26 3.96 - 4.57 m 94.6 1.58 5EBA BH-30 4.57 - 5.18 m 45.9 2.08 7.6

NOTES: np = non plasticYellow cells indicate there is no data available

Passing 2micron

(%) - READ from PSD Activity

15

Liquid Limit (%)

Plastic Limit (%)

Plasticity Index (%)

Passing #200 (%)

Bulk Density in Tube (Mg/m3)

Summary of Lab & In-Situ Data Available for Roberts Bay Marine Sediments (SRK 2004 drill program & EBA 1997 drill program)

% Clay % Silt%

Sand%

Gravel

Undrained Shear Strength

Sample IDLab Soil

Classification

Water Content

(%)

Appendix D Phase I Foundation Investigation (SRK 2004)

Phase I Foundation Investigation Proposed Roberts Bay Jetty Location, Doris North Project, Nunavut, Canada

Prepared for

Miramar Hope Bay Limited

Prepared by

April 2004

Phase 1 Foundation Investigation Proposed Roberts Bay Jetty Location, Doris North

Project, Nunavut, Canada

Miramar Hope Bay Limited Suite 300, 889 Harbourside Drive

North Vancouver, BC V7P 3S1

SRK Consulting (Canada) Inc.

Suite 800, 1066 West Hastings Street Vancouver, B.C. V6E 3X2

Tel: 604.681.4196 Fax: 604.687.5532

E-mail: [email protected] Web site: www.srk.com

SRK Project Number 1CM014.02

April 2004

Author

Dylan MacGregor, M.A.Sc., G.I.T.

Reviewed by

Maritz Rykaart, Ph.D., P.Eng. Senior Geotechnical Engineer

SRK Consulting Phase 1 Foundation Investigation Proposed Roberts Bay Jetty Location Page i

MR/spk Phase1FoundationInvestigation.Report.1CM014.02.MR.Rev02.doc, May. 26, 05, 3:10 PM April 2004

Table of Contents 1 Introduction .................................................................................................................. 1

1.1 Background ......................................................................................................................... 1 1.2 Summary of Drill Program................................................................................................... 1

2 Methodology................................................................................................................. 2 2.1 Drilling ................................................................................................................................. 2 2.2 Laboratory Testing .............................................................................................................. 2

3 Results .......................................................................................................................... 3 3.1 Drilling Hole Locations ........................................................................................................ 3 3.2 General Drilling Conditions ................................................................................................. 3 3.3 Foundation conditions ......................................................................................................... 4

3.3.1 SRK 47 ....................................................................................................................................4 3.3.2 SRK 46 ....................................................................................................................................4 3.3.3 SRK 45 ....................................................................................................................................5 3.3.4 SRK 49 ....................................................................................................................................5

3.4 Laboratory Testing Results ................................................................................................. 5

4 Discussion.................................................................................................................... 6

5 References.................................................................................................................... 8

List of Tables

Table 1: Initial Laboratory Testing Program for Samples from Roberts Bay Geotechnical Drilling, Winter 2004 ........................................................................................................................ 2

Table 2: As-built Drillhole Coordinates, Roberts Bay Geotechnical Drilling, Winter 2004................ 3 Table 3: Results of Initial Laboratory Testing Roberts Bay Geotechnical Drilling, Winter 2004....... 6

List of Figures Figure 1: Proposed Jetty Layout Figure 2: Drill Hole Locations Figure 3: Inferred Jetty Centerline Profile

List of Attachments Attachment A: Drill Logs Attachment B: Laboratory Test Results

SRK Consulting Phase 1 Foundation Investigation Proposed Roberts Bay Jetty Location Page 1

MR/spk Phase1FoundationInvestigation.Report.1CM014.02.MR.Rev02.doc, May. 26, 05, 3:10 PM April 2004

1 Introduction

1.1 Background

An eleven day visit to Miramars Doris North Project was made by Dylan MacGregor (GIT) of SRK Consulting during the period of April 10-20, 2004. The primary purpose of this work was to conduct a geotechnical drilling program at the south end of Roberts Bay. The drilling program targeted foundation conditions in the footprint of the proposed jetty (Figure 1) described in the preliminary surface infrastructure design repor