technical report r1

ASTALDI – ÖZKAR JV

Slope StabilizationTechnical Report

Astaldi – Ozkar JV (Oman)

P.O. Box 238 - PC. 103 - Bareeq Al Shatti

Office 45, 4th Floor; Al Masriq Building

Azaibah, Muscat, Sultanate of Oman

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Contents

1 INTRODUCTION:........................................................................................................................................................3

2 SLOPE STABILIZATION PLAN:..............................................................................................................................4

2.1 DATA FOR SLOPE STABILIZATION AS OF FEBRUARY 20TH.......................................................................................42.2 SLOPE STABILIZATION MEASURES AS OF FEBRUARY 20TH......................................................................................4

3 DEFINITIONS:..............................................................................................................................................................4

4 PROPOSED EQUIPMENT, ALREADY IN PROCESS OF DELIVERY MAINLY COMPOSED BY..............5

5 METHODOLOGY........................................................................................................................................................7

5.1 ALREADY EXCAVATED SURFACES TO BE MAPPED....................................................................................................75.2 ALREADY EXCAVATED AND MAPPED SURFACES TO BE STABILIZED........................................................................85.3 NEW SURFACES AFTER FUTURE EXCAVATIONS........................................................................................................85.4 ADDITIONAL MEASURES FOR FUTURE EXCAVATIONS...............................................................................................8

6 AREAS OF CONCERNS..............................................................................................................................................9





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1 Introduction:

The current project is named as Dualization of Bidbid – Sur Road, Section 1, Package 1-A. The route of Package 1-A

starts from Bidbid in Wilayat of Samail and reaches a point beyond Wadi al Aq. The total length of the package is 40

km.

Picture 1. Existing Bidbid – Sur Road and Projects Route

Cut slope details are given in drawing OM08071-1A-TD-TR-007, in table of “DETAILS OF CUT and FILL SLOPE

and THEIR LOACTIONS” (Appendix – 1). According to above mentioned table the cut angles are 0.25H:1V, if

depth<8.0m and 0.33H:1V, if depth>8.0m, with a berm width 4.0m at every 8.0m depth.

In excavation process both hydraulic jack hammer and blasting method are used. The methods are determined

according to strength of rock in the cut zones.

The determined slope stabilization methods and their details are given in drawings OM08071-1A-TD-G-003,004,005

and 006 (Appendix – 2,3,4 & 5)





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SAMAIL

BID-BID

NIDAB

LIZUGTH

DAHIYAH


1.1 Design for cut and slope stabilization as per contract documents.

Slope inclination parameters according to design





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Mainly slope protection measure in the contract are related to the rock support for excavated areas after cutting, cutting is done by mechanized equipment and with blasting, measures according to design involves rock bolting, wire mesh, shotcrete.





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1.2 Design for cut and slope stabilization as per contract documents

As per excavated areas and according to design parameters, the definition of the slope stabilization must be done by geotechnical department of AOJV and approved by Engineer.

1.2.1 Gathering Geological Data : Contractor’s Geologist and/or Geotechnical Engineer/s collect data from existing slopes for planar, wedge or toppling failure analysis. Also, data for rock mass classification such as color, weathering, strength etc. (Appendix – 6) and discontinuity surveying such as dip angle / dip direction, spacing, aperture, persistence etc. (Appendix – 7) are collected. Those data shall be used for kinematic analysis of existing slope surface.

Contractor’s Geologist and/or Geotechnical Engineer/s scan all existing slope surface and divide the slope

surface in chainages regarding to their conditions and characteristics. After that data collection work starts

chainage by chainage. Those sections are determined comparing with rock masses geological formation, joint

spacing and rate of weathering. Those data are filled in Rock Mass Data Sheet (Appendix – 6) and

Discontinuity Survey Data Sheet (Appendix – 7).

Actual site conditions are visualized with taken photos. Later on those photos shall be added to the geological

map of existing slope.

1.2.2 Analysis of Geological Data: In this process, collected data will be used for kinematic analysis of slope

surface against planar, wedge and toppling failure. Also documentation work is carried out.

The collected data and their results are mentioned and explained below:

Dip angle and dip direction of slope and discontinuities are plotted on stereonets to determine the

possibilities of planar, wedge and/or toppling failures.

Rock Mass Data Sheet is filled regarding to site study divided chainages.

Discontinuity Survey Data Sheet is filled regarding to site study for divided chainages.

Rock Mass Rating (RMR) value is calculated reference to rating table of RMR (Appendix – 8,

Beiniawski, 1989).

Reference to drawing OM08071-1A-TD-G-005, notes 17 (Appendix – 4); the type of rock determines as

listed below.

TYPE A : FRESH – SLIGHTLY WEATHERED ROCKS

A – 1: Fresh – Slightly weathered, blocky with widely spaced and/or tight joints and low frequency of daylighting on the slope.A – 2: Fresh – Slightly weathered rock mass and discontinuities are relatively more weathered than type – 1, moderately jointed and low frequency of daylighting on the slope.A – 3: Fresh – Slightly weathered with prominent and persistent hazardous discontinuity/ies daylighting onto slope with 20° of the cut azimuth.





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TYPE B: MODERATELY – SLIGHTLY WEATHERED (DOMINANTLY MODERALY WEATHERED)

B – 1: Moderately – Slightly weathered, widely spaced and/or tight joints with no major

hazardous daylighting onto slope.

B – 2: Moderately – Slightly weathered moderately – closely spaced jpints, less tight and/or

relatively more weathered than type – 1, with no major hazardous daylighting onto slope.

B – 3: Moderately – Slightly weathered with major hazardous discontinuity/ies daylighting onto

slope with 20° of the cut azimuth.

TYPE C: HIGHLY WEATHERED ROCK and DISCONTINUITIES

1.2.3 Type of slope stabilization measurements are decided reference to table on the drawing OM08071-1A-TD-G-005 (Appendix – 4).

ROCK TYPE STABILIZATION TYPE DISTRIBUTION

A1 - -

A2 BOLTS TYPE 1 or TYPE 2 D1

A3 BOLTS TYPE 2 or ANCHORING D2

B1 BOLTS TYPE 1 or TYPE 2 D1

B2 BOLTS TYPE 1 or TYPE 2 D1

B3 BOLTS TYPE 2 or ANCHORING D2

C BOLT TYPE 1 D1

D1: Spot Bolting of Unstable Rock Blocks. The Application of Bolt Types Shall Be Determined by the Engineer.

D2: Systematic Bolting of Zones with A Prominent Discontinuity Dipping onto Slope. The Systematic Bolting

Shall Be Applied to the Prominent Discontinuity, but Not to the Whole Rock Cut Face. The Engineer Shall

Determine the Zones Where Anchoring is Deemed Necessary.

1.2.4 Geological Mapping: The overall purpose of a geological mapping is to define a set or sets of discontinuities

or a single feature. Additionally, geological map has all sort of information which is required by Engineer.

Summary of data and information on the geological map is listed below:

Slope surface drawing. Dip angle and dip direction of slope and discontinuities Elevation of slope bottom and top levels. Rock Description. Discontinuity Data: Stereonets for planar, wedge and toppling failure. Rock Mass Rating (RMR) values and its determination. Rock Type (ref. OM08071-1A-TD-G-005, note 17) Recommended slope stabilization measures according to table in drawing OM08071-1A-TD-G-005 and

site conditions. Updated slope photos.





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1.2.5 Request For Inspection (RFI): Contractor submits a RFI for site inspection to determine the slope stabilization measures on existing slopes according to Engineer’s comments and instruction.

The geological map and all data sheets from site studies shall be attached to the RFI for site inspection.

Type, number and location of slope stabilization measures shall be determined and spotted in this site

inspection with the Engineer. The locations of rock bolts and/or rock anchors will be marked on site

according to Engineer’s decision. Also area of shotceting and wirenetting shall be marked on site.

Shop Drawings: According to reply and notes of Engineer, shop drawings will be prepared and submitted

with agreed documents for to get approve.

Request for Inspection (RFI) for Execution: As a last step, Contractor submits a RFI right before starting to

execution process. The Engineer shall inspect the materials and process of execution of slope stabilization

measures.

2 Process for application of slope stabilization measures

The process for approval of the slope stabilization measures, starting from the design from contractual documents,

technical specifications and constructions drawings.

AOJV has followed the procedure as per technical specifications for submission of all related document and

materials in order to get the approvals.

Starting from material submission, process that take more than 6 months just for the final approval of the materials

for all stabilization measures as shown in the following table:

S.R NO

Ref. No. Rev.Date of

Submission to DAR

Date of Reply

Description STATUS

Pending Days with

DAR

Total Pending

Days From first

SubmissionMaterial Approval

1AOJV/BBS/MAR_0055/00 0 6-Mar-12 14-Mar-12

Wire Mesh 6mm ø, 100mm x100mm Spacing (for Slope Protection)

Approved as noted

8 8

2AOJV/BBS/MAR_0069/00 0 18-Mar-12 28-Mar-12

Steel insert, For Fixing Wire Mesh Slope Protection Works

Revise & Resubmit

10 10

3AOJV/BBS/MAR_0070/00 0 18-Mar-12 28-Mar-12 High Early Strength Cement Grout for Fixing of Bolts

Approved as Noted

10 10

4 AOJV/BBS/MAR_0079/00 0 7-Apr-12 16-May-12 Shotcrete Mix Design Other 3953

5AOJV/BBS/MAR_0079/01 1 30-Jul-12 13-Aug-12 Shotcrete Mix Design

Approved as Noted

14

6AOJV/BBS/MAR_0080/00 0 8-Apr-12 16-Apr-12

Geoextile Non - Woven Filter Fabric - ALYAF XP Geotextile

Revise & Resubmit

812


Geoextile Non - Woven Filter Fabric - ALYAF XP Geotextile

Approved as Noted

4


Steel insert, For Fixing Wire Mesh (L Shaped Hook Bar-12mm Dia, Grade B500) Slope Protection Works

Approved as Noted

1 1

9AOJV/BBS/MAR_0087/00 0 4-May-12 12-May-12 Rock Bolt Type 1 and Type 2

Approved as Noted

8 8

10AOJV/BBS/MAR_0092/00 0 15-May-12 20-May-12 Geotextile non-Woven Typar SF 65 and Typar SF94

Approv ed as Noted

5 5

11 AOJV/BBS/MAR_0100/00 0 4-Jun-12 20-Jun-12 Rock Bolt Type 1 and Type 2 (Dia 26.5 mm - VSL SAS Approved as 16 16





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stress bar 950/1050, hot rolled, ribbed - right hand thread)

Noted

S.R NO


Submission to DAR

Date of Reply

Description STATUS

Pending Days with

DAR

Total Pending

Days From first

Submission

12AOJV/BBS/MAR_0106/00 0 19-Jun-12 16-Jul-12 Shotcrete Mix Design

Revise & Resubmit

2745

13AOJV/BBS/MAR_0106/01 1 28-Jul-12 15-Aug-12 Shotcrete Mix Design

Approved as Noted

18

14AOJV/BBS/MAR_0110/00 0 24-Jun-12 2-Jul-12

Meyco Flowcale Admixture for Post Tensioning Cable Grout

Approved as Noted

8 8

15AOJV/BBS/MAR_0114/00 0 25-Jun-12 30-Jun-12

Rock Bolt Type 2 ( dia 32mm - VSL stress bar 950/1050, hot rolled, ribbed right hand thread)

Approved as Noted

5 5

16AOJV/BBS/MAR_0115/00 0 27-Jun-12 2-Jul-12 Grout for Anchor Bolts, Slope Stablization

Revise & Resubmit

514

17AOJV/BBS/MAR_0115/01 1 2-Jul-12 11-Jul-12 Grout for Anchor Bolts, Slope Stablization

Approved as Noted

9

18AOJV/BBS/MAR_0130/00 0 4-Aug-12 14-Aug-12 Wire Netting for Slope Protection

Revise & Resubmit

1019

19AOJV/BBS/MAR_0130/01 1 10-Sep-12 19-Sep-12 Wire Netting for Slope Protection

Approved as Noted

9

20AOJV/BBS/MAR_0134/00 0 19-Sep-12 6-Oct-12 Rock Anchors

Revise & Resubmit

1720

21AOJV/BBS/MAR_0134/01 1 16-Dec-12 19-Dec-12 Rock Anchors

Approved as Noted

3

22AOJV/BBS/MAR_0138/00 0 13-Oct-12 16-Oct-12 Spikes for Wire Netting for Slope Protection

Approved as Noted

3 3

After the approval of the required material, the process continues with the approval of method statements, drawings,

geological mapping and recommendations for slope protection measures, process started on 2011 and still in progress:

S.R NO


Submission to DAR

Date of Reply

Description STATUS

Pending Days with DAR

Total Pending

Days From first

SubmissionMethod of Statement

1AOJV/BBS/MSS_0017/00 0 4-Aug-12 8-Aug-12

Method Statement for Rock Bolting Trial & Pullout Test.

Approved as Noted

4 4

2AOJV/BBS/MSS_0025/00 0 17-Oct-12 24-Dec-12 Method Statement for Geofoam Filling Over Culverts

Revise & resubmit

68 68

3AOJV/BBS/MSS_0027/00 0 2-Dec-12 5-Dec-12

Method Statement for Rock Anchors Installations (Note : Reffer Comment No. 4 on MAR-0134/00)

Revise & resubmit

38

4AOJV/BBS/MSS_0027/01 1 12-Dec-12 17-Dec-12

Method Statement for Rock Anchors Installations (Note : Reffer Comment No. 4 on MAR-0134/00)

Approved as Noted

5

5AOJV/BBS/MSS_0029/00 0 2-Feb-13 5-Feb-13 Method Statement for Shotcrete

Revise & resubmit

3 3

6AOJV/BBS/MSS_0029/01 1 19-Feb-13 24-Feb-13 Method Statement for Shotcrete

Approved as Noted

5 5

Transmittal of Drawings

1AOJV/BBS/TDW_0259/00 0 15-Aug-12 29-Aug-12

Slope Protection Detail at km 8+050 to 8+160,Slope Protection Detail at km 33+730 to 33+910

Revise and Resubmit

14

292

AOJV/BBS/TDW_0259/01 1 22-Sep-12 29-Sep-12 Slope Protection Detail at km 8+050 to 8+160 LHSRevise and Resubmit

7

3AOJV/BBS/TDW_0259/02 2 2-Oct-12 9-Oct-12 Slope Protection Detail at km 8+050 to 8+160 LHS

Revise and Resubmit

7

4AOJV/BBS/TDW_0259/03 3 8-Oct-12 9-Oct-12 Slope Protection Detail at km 8+050 to 8+160 LHS

Approved as Noted

1

5AOJV/BBS/TDW_0262/00 0 22-Aug-12 29-Aug-12 Slope Protection Detail at km 33+250 to 33+390

Revise and Resubmit

7 7

6AOJV/BBS/TDW_0265/00 0 25-Aug-12 29-Aug-12 Slope Protection Detail at km 33+620 to 33+730 LHS

Revise and Resubmit

4 4

SITE CLARIFICATION1 AOJV/BBS/SCR_0050 2-Jan-12 15-Jan-12 The transversal slope 2% toward the curbe is not clear 13 133 AOJV/BBS/SCR_0136 23-Jun-12 26-Jun-12 Cut Slope between Sta. 12+910 to Sta. 13+220 3 34 AOJV/BBS/SCR_0153 15-Aug-12 4-Sep-12 Slope Protection 20 20

Transmittal of Documents

1AOJV/BBS/TDC/0043/00 0 22-Oct-11 24-Oct-11

Preliminary Geotechnical Report for Completed Borhole to dates

Revise & Resubmit

2

65

2 AOJV/BBS/TDC/0043/01 1 13-Nov-11 24-Nov-11 Subsurface investigation sta. 0+225 to 8+990Revise & Resubmit

11

3 AOJV/BBS/TDC/0043/02 2 12-Dec-11 15-Jan-12 Subsurface investigation sta. 0+225 to 8+990Revise & Resubmit

34

4 AOJV/BBS/TDC/0043/03 3 15-Feb-12 22-Feb-12 Subsurface Investigation from (Sta. 0+255 to 8+990) Others 7

5 AOJV/BBS/TDC/0043/04 4 27-Mar-12 7-Apr-12Subsurface Investigation from (Sta. 0+255 to 8+990),

Text for Geotechnical Final ReportApproved as

Noted11





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6 AOJV/BBS/TDC/0068/00 0 21-Dec-11 21-Jan-12 Subsurface investigation from (Sta. 9+170 to 19+642) Revise & 31 39

S.R NO


Submission to DAR

Date of Reply

Description STATUS


Total Pending

Days From first

Submission

S.R NO


Submission to DAR

Date of Reply

Description STATUS


7 AOJV/BBS/TDC/0068/01 1 3-Apr-12 11-Apr-12Subsurface Investigation from (Sta. 9+000 to 19+642),

Text for Geotechnical Final ReportApproved as

Noted8

8 AOJV/BBS/TDC/0137/00 0 25-Mar-12 26-Mar-12Individual Test Reports Summary as per Approved

Laboratory Test Schedule up to Date (for Subsurface investigation submitted through TDC 0033/05)

Approved 1 1

9 AOJV/BBS/TDC/0138/00 0 26-Mar-12 27-Mar-12Individual Test Reports Summary as per Approved

Laboratory Test Schedule up to Date (for Subsurface investigation submitted through TDC 0033/05)

Approved as Noted

1 1

10 AOJV/BBS/TDC/0141/00 0 1-Apr-12 7-Apr-12Proposed Locations of Boreholes for subsurface soil

investigation under structures for Sta. 8+990Approved as

Noted6 6


investigation under structures Wadi Bridges Sta. 29+150 and Sta. 29+545

Revise & Resubmit

1

2


investigation under structures Wadi Bridges Sta. 29+150 and Sta. 29+545

Approved as Noted

1

13 AOJV/BBS/TDC/0150/00 0 4-Apr-12 7-Apr-12Updated Boreholes Locations for Subsurface Soil

Investigation Under StructureApproved as

Noted3

614 AOJV/BBS/TDC/0150/01 1 11-Apr-12 14-Apr-12

Updated Boreholes Locations for Subsurface Soil Investigation Under Structure (Piezpmeter Location

PM-10 changed at bridge 29+150)

Approved as Noted

3

15 AOJV/BBS/TDC/0157/00 0 8-Apr-12 15-Apr-12Updated Borehole Locations for subsurface

Investigation at Bridge 30+098.5Approved as

Noted7 7

16 AOJV/BBS/TDC/0175/00 0 18-Apr-12 22-Apr-12Proposed Locations of Boreholes for Subsurface Soil

Investigation for revised Box Culverts. (As per Site Clarification No. 094)

Others 4 4

17 AOJV/BBS/TDC/0177/00 0 22-Apr-12 7-May-12 Propose Slope Protection No. 1 at Km 8+100Approved as

Noted15 15

18 AOJV/BBS/TDC/0178/00 0 23-Apr-12 3-May-12 Propose Slope Protection No. 2 at Km 6+200Approved as

Noted10 10

19 AOJV/BBS/TDC/0182/00 0 28-Apr-12 7-May-12 Proposed Slope Protection No. 1 at KM 38+200Approved as

Noted9 9

20 AOJV/BBS/TDC/0191/00 0 6-May-1215-May-

12Subsurface Investigation Report for Overpass at Sta.

39+622 & Box culverts at Sta. 39+984Approved 9 9


12Subsurface Investigation Report for Underpass at

Sta.2+622 & Box Culvert at Sta. 2+695Approved 9 9


12Subsurface Investigation Report for Bridge at Sta.

36+600Approved 6 6

23 AOJV/BBS/TDC/0213/00 0 26-May-12 4-Jun-12Subsurface Investigation of Box Culverts at Sta.

8+474, 22+494, 22+580, 23+478 & 24+350Approved as

Noted9 9


12Geotechnical Investigation of new Bowrehole BH-19

Approved as Noted

0 0

25 AOJV/BBS/TDC/0217/00 0 28-May-12 2-Jun-12 Propose Slope Protection No. 1 at Km 33+800Approved as

noted5 5


noted5

727 AOJV/BBS/TDC/0218/01 1 14-Jul-12 16-Jul-12

Propose Slope Protection No.1 at Km 35+900Quality Measurement Sheet form Ch. 35+820 to Ch.

35+920Drawing No. AOJV-BBS-CS-03583 to 03593 (Rev.1)

Revise & Resubmit

2


noted5 5

29 AOJV/BBS/TDC/0223/00 0 3-Jun-12 20-Jun-12 Propose Slope Protection No. 1 at Km 33+300Approved as

noted17 17


noted16 16


noted2 2

32 AOJV/BBS/TDC/0237/00 0 24-Jun-12 2-Jul-12Subsurface Investigation Report of Bridge at sta.

31+750Revise & Resubmit

815

33 AOJV/BBS/TDC/0237/01 1 28-Jul-12 4-Aug-12Subsurface Investigation Report of Bridge at sta.

31+750Approved as

noted7

34 AOJV/BBS/TDC/0252/00 0 8-Jul-12 14-Jul-12 Proposed Slope Protection No.1 at Km 7+500Revise & Resubmit

6 6

35 AOJV/BBS/TDC/0259/00 0 10-Jul-12 14-Jul-12 Proposed Slope Protection No.1 at Km 35+250Revise & Resubmit

4 4

36 AOJV/BBS/TDC/0263/00 0 14-Jul-12 25-Aug-12Geotechnical Report for Foundations of Arch Bridge at

Station 11+256Others 42 42

37 AOJV/BBS/TDC/0264/00 0 14-Jul-12 25-Aug-12Geotechnical Report for Foundations of Arch Bridge at

Station 39+600Others 42 42

38 AOJV/BBS/TDC/0265/00 0 14-Jul-12 8-Sep-12Geotechnical Report for Foundations of Bridge at

Station 8+866 (Fugro)Others 56 56

39 AOJV/BBS/TDC/0281/00 0 22-Jul-12 24-Jul-12 Slope Stabilization Report for First Slope Cut at Km 8+200

Slope Stabilization Report for Second Slope Cut at Km

Approved as Noted

2 4





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8+200

S.R NO


Submission to DAR

Date of Reply

Description STATUS


Total Pending

Days From first

Submission

40 AOJV/BBS/TDC/0281/01 1 28-Jul-12 30-Jul-12Slope Stabilization Report for First Slope Cut at Km

8+200Approved as

Noted2

41 AOJV/BBS/TDC/0286/00 0 25-Jul-12 30-Jul-12Geotehcnical Report for Surface Investigation report of

Culverts and Trial Pits between Station 34+428 to 36+450

Revise & Resubmit

5 46

S.R NO


Submission to DAR

Date of Reply

Description STATUS


42 AOJV/BBS/TDC/0286/01 1 3-Sep-12 11-Sep-12Geotehcnical Report for Surface Investigation report of

Culverts and Trial Pits between Station 34+428 to 36+450

Revise & Resubmit

8

43 AOJV/BBS/TDC/0286/02 2 9-Oct-12 16-Oct-12Geotechnical Investigation Report for Subsurface of Culverts and Trial Pits between Station 34+428 to

36+450

Revise & Resubmit

7

44 AOJV/BBS/TDC/0286/03 3 10-Dec-12 5-Jan-13 Subsurface Investigation Report of Culverts and Trial

Pits between Station 34+428 to 36+450Revise & Resubmit

26

45 AOJV/BBS/TDC/0292/00 0 30-Jul-12 4-Aug-12Subsurface Investigation Report of Bridge at sta.

28+350Approved as

Noted5 5

46 AOJV/BBS/TDC/0293/00 0 30-Jul-12 8-Aug-12

Slope Stabilization Report for 2nd Slope Cut at Km 33+700, Slope Stabilization Report for 3rd Slope Cut

at Km 33+700, Slope Stabilization Report for 4th Slope Cut at Km 33+700, Slope Stabilization Report for 5th Slope Cut at Km 33+700, Slope Stabilization

Report for 6th Slope Cut at Km 33+700

Approved as Noted

9

47 AOJV/BBS/TDC/0312/00 0 22/Aug/12 2-Sep-12Subsurface Investigation Report of Bridge at Station


11

6748 AOJV/BBS/TDC/0312/01 1 24/Sep/12 10-Oct-12Subsurface Investigation Report of Bridge at Station


16

49 AOJV/BBS/TDC/0312/02 2 22/Oct/12 1-Dec-12Subsurface Investigation Report of Bridge at Station

29+150Approved 40

50 AOJV/BBS/TDC/0350/00 0 26/Sep/12 6-Oct-12Slope Stabilization Remedial Plan for Open Cut

SlopesRevise & Resubmit

10 10

51 AOJV/BBS/TDC/0384/00 0 7/Oct/12 29-Jan-13Geotechnical Investigation Report for Foundations of

Bridge at Station 36+600 , Foundation Recommendations for Bridge 36+600

Revise & Resubmit

114 114

52 AOJV/BBS/TDC/0389/00 0 9/Oct/12 3-Nov-12Geotechnical Investigation Report for Foundations of

Bridge at Station 30+098Revise & Resubmit

25

9053 AOJV/BBS/TDC/0389/01 1 9/Dec/12 24-Dec-12Geotechnical Investigation Report for Foundations of


15

54 AOJV/BBS/TDC/0389/02 2 31/Dec/12 19-Feb-13Geotechnical Investigation Report for Foundations of


50

55 AOJV/BBS/TDC/0400/00 0 17/Oct/12 30-Jan-13Geotechnical Investigation Report for Foundation of


105 105

56 AOJV/BBS/TDC/0428/00 0 2/Dec/12 15-Dec-12Slope Protection Details KM 33+730, LHS (Ref.

TDW_0265/00)Approved as

Noted13 13

57 AOJV/BBS/TDC/0429/00 0 2/Dec/12 4-Dec-12

Geotechnical Report No.1 for KM 33+050 & KM 32+850 Cut Slope attached Cross Sections from Station 32+850 to 32+960 Rev. 0A & 33+010 to

33+200 Rev. 0A (Ref. RFI_RD/01023 & RFI_RD/01027)

Revise & Resubmit

2

9

58 AOJV/BBS/TDC/0429/01 1 9/Feb/13 16-Feb-13

Geotechnical Report No.1 for KM 33+050 & KM 32+850 Cut Slope attached Cross Sections from Station 32+850 to 32+940 Rev. 0A & 33+010 to

33+150 Rev. 0A (Ref. RFI_RD/01023 & RFI_RD/01027)

Approved as Noted

7

59 AOJV/BBS/TDC/0472/00 0 31/Dec/12 9-Jan-13Geotechnical Investigation Report for Foundations of


914

60 AOJV/BBS/TDC/0472/01 1 4/Feb/13 9-Feb-13Geotechnical Investigation Report for Foundations of

Bridge at Station 29+545Approved as

Noted5

61 AOJV/BBS/TDC/0485/00 0 14/Jan/13 15-Jan-13Geotechnical Investigation Report for Foundation s of

Overpass at Sta. 22+720Revise & Resubmit

1 1

62 AOJV/BBS/TDC/0492/00 0 23/Jan/13 10-Feb-13

Slope Protection Details KM 31+040 to 31+080, Bench 6 RHS Shotcrete (Drw.No. AOJV-SK-0018),

Slope Protection Details KM 31+146 to 31+210, Bench 6b RHS Shotcrete (Drw.No. AOJV-SK-0019)

Slope Protection Details KM 31+160 to 31+200, Bench 7 RHS Shotcrete (Drw.No. AOJV-SK-0021)

Approved as Noted

18 18

63 AOJV/BBS/TDC/0499/00 0 28/Jan/13 10-Feb-13

Slope Protection Details KM 36+840 to 36+890, Bench 6 LHS Type-1 Rock Bolt & Shotcrete Sheet 1 of

6 (Drw.No. AOJV-SK-0015),Slope Protection Details KM 36+870 to 36+920,

Bench 7 LHS Type-1 Rock Bolt Shotcrete Sheet 1 of 5 (Drw.No. AOJV-SK-0016)

Slope Protection Details KM 36+946 to 36+990, Bench 8 LHS Type-1 Rock Bolt Shotcrete Sheet 1 of 2

(Drw.No. AOJV-SK-0017)

Approved as Noted

13 13





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64 AOJV/BBS/TDC/0501/00 0 29/Jan/13 9-Feb-13Slope Protection Details KM 31+050 to 31+066,

Bench 7 RHS Shotcrete (Drw.No. AOJV-SK-0020)Approved as

Noted11 11

S.R NO


Submission to DAR

Date of Reply

Description STATUS


Total Pending

Days From first

Submission


Slope Protection Details KM 34+010 to 34+070, Bench 6 LHS Type-1 Rock Bolt (Drw.No. AOJV-SK-

0013),Slope Protection Details KM 34+010 to 34+040,

Bench 7 LHS Type-1 Rock Bolt (Drw.No. AOJV-SK-0013)

Slope Protection Details KM 34+205.018 to 34+160, Bench 4 RHS Type-1 Rock Bolt, Shotcrete and

wiremesh (Drw.No. AOJV-SK-0014)

Approved as Noted

19 19

66 AOJV/BBS/TDC/0514/00 0 16/Feb/13 24-Feb-13Geotechnical Report No.2 for Km 35+000 Cut Slope, Attached Cross Sections from Sta. 34+820 to 35+000

Rev.0

Revise & Resubmit

8 8


Slope Protection Details KM 8+534 to 8+580, Bench 2 RHS (Drw.No. AOJV-SK-0026),

Slope Protection Details KM 8+530 to 8+580, Bench 2 LHS Type-1 Rock Bolt Shotcrete & Wiremesh

(Drw.No. AOJV-SK-0027)

Others 8 8

68 AOJV/BBS/TDC/0522/00 0 16/Feb/13 23-Feb-13Slope Protection Details KM 8+548 to 8+590, Bench 3 LHS Shotcrete & Wiremesh (Drw.No. AOJV-SK-0025)

Approved as Noted

7 7

69 AOJV/BBS/TDC/0523/00 0 16/Feb/13 23-Feb-13Slope Protection Details KM 38+040 to 38+090,

Bench 5 RHS (Drw.No. AOJV-SK-0024)Approved as

Noted7 7

AOJV/BBS/TDC/0527/000 18/Feb/13 25-Feb-13 Geo support Work Methodology (Form TEC-01)

Approved as Noted

7 7




Approved as Noted

3 3




Approved as Noted

5 5

72 AOJV/BBS/TDC/0539/00 0 25-Feb-13 1-Mar-13Slope Protection Stabilization No. 1 for Bench-5 from

Km 31+050 to 31+200

OUTSTANDING FOR

APPROVAL4 4

3 Slope Stabilization Plan:

The Contractor is planning to cover all the activities in relation with slope stabilization according to the requirement of

the project. For this it is necessary some measures in order to guaranty to sequence of the works according to the

update approved locations.

3.1 Data for slope stabilization as of February 20th:

Total estimated exposed surface for the project 822,264 sq m.

Total exposed surface according to site information: 170,872 sq m.

Total mapped surface according to geotechnical department: 38,168 sq m.

3.2 Slope stabilization measures as of February 20th:

Shotcrete 100 mm 1,765 sq m

Shotcrete 50 mm 4,735 sq m

Wire Netting 2,545 sq m

Rock Bolt Type 1 810 lin m





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Rock Bolt Type 2 36 lin m

4 Definitions:

According to defined quantities of work, AOJV is preparing a full program to increase the performance of the works

and also recover the uncovered areas.

With this, AOJV plans consider including more subcontractors for slope stabilization work, local companies that can

support the construction activities with equipment and labor for drilling of rock bolts, rock anchors and weep holes.

Also, for spaying shotcrete with wire mesh and concrete for leveling and protection of the berms.

AOJV is supporting the works for cleaning of the berms with a team of labors, this task results very hard to the people

on site, due to the difficulties for access and also for safety. The cleaning of the berms will continue in the same way,

additionally equipment will be used to support the jobs.

The cleaning of the berms also will be done with air compressed and light equipment.

At the same time, AOJV is acquiring additional equipment to complement the slope stabilization works, specific

equipment to give support at the operations of cleaning of berms, drilling for rock bolting and weep holes, shotcreting

and handling of materials.

The work for cleaning of the berms if followed directly from Geotechnical Department, this department is mobilizing

additional resources to complete the cleaning of the berms, also the safety of the personnel it is important for AOJV,

for this reason, the people for cleaning of berms use safety belt to be hanged of anchored life line in the slope.





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5 proposed equipment, already in process of delivery mainly composed by:

AOJV, in order to improve the methodology of works, looking for reduction of time to complete the works in the

exposed areas, is planning the delivery of additional equipment only to support all the tasks in relation with slope

protection, starting from cleaning, survey and application of slope stabilization measures:

JCB Mini 8025 (Excavator) for cleaning:

Baby Giraffe (Drilling Machine) For rock bolting, anchors & weep holes:





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Roto Merlo 40.3 (Telehandler) for supporting the activities on site:

AOJV has on site equipment for shotcreting, but is looking for additional solutions to reach the upper benches.

Meyco Oruga (Shotcrete machine) for spraying of shotcrete in upper benches:





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Meyco Suprema (Shotcrete Pump high capacity) for feeding of shotcrete machine in upper benches:





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With the support of the local companies as Bumi Engineering (Approved as subcontractor), Al Manar (Approved as

subcontractor) and Swiss Co (In process of approval), AOJV is planning to go forward for the stabilization measures

of the already approved locations.

In order to cover all exposed areas in the project, AOJV is planning to increase the productivity of the works for as-

built survey, geological mapping, kinematic analysis, discontinuity analysis and slope protection recommendations.

For this reason, AOJV submitted and had obtained the approval for a third specialized company for the collecting of

the data on site and post processing of the data with specialized people and specific software.

Geosupport Technical Offer was submitted to the consultant with the proposed methodology to realize the works in the

following sequence:

As a first step, Geosupport/AOJV will make the topographic survey in all exposed areas of rock due to cuts, after will

be completed the geological mapping in the surface of the exposed areas. Subsequently will be performed the general

mapping in the work area in order to determine the existence of major faults or global stability problems. Following

the process with expert geologist from both companies, the production of paper works for mapping and kinematic

analysis, including recommendations for slope stabilization measures, the work will be complemented with permanent

presence on site and updating information for data processing.





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Geosupport (Specialized Company for geological mapping, slope survey, monitoring and control of slopes, data

processing and kinematic analysis):

http://www.geosupport.cl

6 Methodology

AOJV has detected that the current process of slope stabilization measures take around of 8-10 days to be completed,

starting from geological mapping and approved shop drawings. This long period for the process is affecting the

sequence of the works and is creating delays in the application of the stabilization measures. In order to reduce the

time AOJV propose, the revision of the methodology of the works as follow:

6.1 Already excavated surfaces to be mapped:

1. For all open areas and exposed slopes as of date of this report, where the geological mapping still pending, the increasing of resources in order to complete the cleaning of the berms will be established immediately.

2. As-built topographical survey will be done after cleaning in order to get the actual conditions of the site and to allow at geological team take accurate information.

3. Geological mapping after cleaning and survey will continue using the traditional system with AOJV geologist, after the arrival of the specialized company, the mapping will start with the methodology as per Geosupport Technical Proposal.

4. The resulting geological mapping will be submitted to the consultant for approval, including kinematic analysis and slope protection measures.

5. After approval of mapping and slope protection measures, the application of the measures will be applied immediately on site.

6. The record of site works will be reflected in as-built drawings for billing purposes and consultant revision.

6.2 Already excavated and mapped surfaces to be stabilized:

1. The submitted documents must be approved after revision of Consultant, including slope stabilization measures.

2. The application of slope stabilization measures will be done after approval of geological mapping and stabilization measured as per approved documents.

3. The record of site works will be reflected in as-built drawings for billing purposes and the consultant revision.

6.3 New surfaces after future excavations:

1. Cleaning of the berms will be done after cleaning of the excavation of the immediately bottom level, including manual and mechanized cleaning.





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http://www.geosupport.cl/


2. As-built survey will be done after cleaning with 3d Laser Scanning Technology.3. Geological mapping will be made using 3D Laser Scanning Technology, visual inspection of surface by

expert Geology and data processing.4. The resulting data processing for geological mapping and as-built survey will be submitted to the consultant

for approval, including kinematic analysis, rock classification, slope stabilization measures as per technical specifications and construction drawings.

5. After approval of the geological mapping, the application of the measures will be applied immediately on site.6. The record of site works will be reflected in as-built drawings for billing purposes and the consultant revision.

6.4 Additional measures for future excavations:

1. General analysis of the surface must be done before to continue with the excavation in the open areas in order to establish the application of the design parameters according to the global stability of the zone. For this, expert geologist will do the visual inspection, surface mapping and geological analysis supported by high technology.

2. For new areas to be open for excavation, the complete analysis must be done as per above recommendation including ortho-photos, stratigraphic analysis and geological mapping.

3. Where the excavation needs to be done applying drill and blast methodology, geology department will do the study of the zone and will recommend the specific parameters to be used in the blasting design. Blasting must be done as per approved method statements and local authority permits.

4. Where the excavation needs to be done applying mechanical methodology, geology department also will recommend the necessary equipment to excavate according to approved method statements.

5. If the geological conditions require application of different measures, as increase of slope inclination, additional subsurface investigation, additional slope stabilization beyond the contract provisions. AOJV will submit to the consultant the proposal with the recommendations for analysis and approval.

7 Areas of concerns:

AOJV have identified some specific locations where the geological conditions of the ground require additional

measures.

1. Station 5+300 to Station 5+500, highly fractured stones in the surface of the hill and big boulders creating unsafely conditions for the road, slope stabilization measures must be submitted for approval.

Note: Additional works need to be done in this location with specific method statement and highly skilled people.





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Proposed solution will be applicable using escalators and specialized company to removal the big boulders and

cleaning of the hill. After this will be required the application of stabilization measures as per construction drawing

OM08071-1A-TD-G006 - Slope stabilization measures 5.

2. Station 6+200, rock characterization reporting unstable material, due to this, the recommendation for reshaping of slope is required.

Insert Cross Section

3. Station 12+500 to 13+500, highly fractured stones in the surface of the hill and big boulders creating unsafely conditions for the road, slope stabilization measures must be submitted for approval, including unforeseen works in the contract.





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Additional drainage system is needed in the hill in order to control the water in rainy season in small water courses shown in the above picture.

The proposed plan in this location will be the same as described for station 5+300 to station 5+500.

4. Station 23+500 to 23+800, share zone identified in the area with loose material and colluvium traces in the ground, change of slope inclination from the lower berm is required.

INSERTAR FOTO Y CROSS SECTION





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5. Station 30+000 to 31+000, trace of fault zone has been discovered in the upper benches, deeper analysis is required.


6. Station 31+000 to 33+000, big fault zone has been detected in the area, traces of sharing joints, highly fractured rock and sedimentary colluvium layers in the area require deeper analysis and redesign of the slope inclination from the lower benches.

This zone in particular must be treated very carefully, for this reason AOJV has prepared the following report

specifically for this stretch between station 31+000 to station 33+000

6.1 Deep Trenches between 31+000 and 33+000 km Bidbid – Sur

In the mountainous area of package 1 Bidbid-Sur, between 31+000 and 33+000 km, the highway’s carriage goes

through a very dramatic geological formation that, in ancient times, had been affected by powerful tectonic

movements.

Depending on their nature, rocks affected by strong tectonic stresses could present plastic deformations, which are

folded into themselves, or rigid deformations, characterized by fractures and cuts formations.

The igneous rocks present throughout the alignment are the Ophiolities type (gabbro, peridotite, dunite, harzburgite

etc.) and they have mainly rigid and fragile behavior, similar to vitreous material. The rocks responded to the tectonic





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stress, either with dislocations of big masses onto the sliding layers – fault planes-, either with a consistent fracturing

of dislocated rocks.

The overall shifts of rock’s portions hadn’t happened all at once but at intervals and with pushes and stresses having

discordant direction. This is the main reason why we have different typology “families” of fractures, each one groups

sub parallel fault planes, which are consequence of one tectonic event.

The composition of these “families” of fractures sub divides the rocks in smaller and smaller elements; the frequency

and orientation of the various fault planes, conditions the stability of the natural mountainous slopes, as well as the

excavated trenches.

There are zones particularly affected tectonically, where the degree of rock’s fracturing is so extreme that it transforms

the material into clusters of silted/sandy inconsistent conglomerated with boulders and stones of the original rocks,

and other zones where the rock’s fracturing is of minor intensity but still present.

Throughout geological time processes, the weathering agents had shaped the territory removing from mountainous

zones a great amount of material easily abradable, especially the once strongly affected tectonically. We could argue

that now days this natural process hasn’t been completed yet, as had been found vast zones where there are layers of

residually tectonically affected materials.

Trench Excavation

The consistent rock’s fracturing, which can be observed during a simple superficial relieve, has been found also

throughout the trench’s excavation. As previously argued tectonic stresses had affected dramatically this terrain but, as

easily guessable, not in homogenous manner.

Difference of rock’s fracturing it’s not showing on area distant apart but, in function of the position of the rocks or the

orientation of the fractures, could be observed alterations in the excavation of the same trench where the characteristics

of the slopes, right and left sides, could show relevant differences.

One of the elements that could characterize fracturing degree, and thus the stability, of the rocks are the coring marks

left by the “presplitting” of the slopes exposed during the excavation.

Thanks to the layout of the cores and the moderated blasting charge used, the presplitting, allows to divide rocks which

should stay in position from the other that have to be removed, limiting the propagation of the stress induced by the

blasting of the central part of the trench.

During the coring of the presplitting, executed by rotary-percussion drill, it’s not possible to evaluate the degree of

fracturing of the rocks, neither throughout time variation and advancement of the drill bit or other methods. The

degree of fracturing becomes evident only after the material from trench’s nucleus is removed and slopes are exposed.

More stable rocks, characterized by a moderated degree of fracturing, is evident the trace of the presplitting cores to

witness a correct excavation method; Very fractured rocks are less stable and trace of the presplitting cores is removed

with the removal of the unstable material from the slope.

As could be observed on the two following picture concerning approximately km 31+000, these two diverse situations

could occur concurrently on the slopes of the same trench. The left trench –although executed onto very fractured





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rocks- shows evidently traces of presplitting, while onto the right one – much more fractured- these traces are less

consistent.

Potentially critical zones

In the zone concerning the end of km 30 to km 34 there are the deepest trenches of the project’s alignment, with

excavation cuts reaching 140 m in depth.

The first excavations have exposed a very complex surface which shows important converging fault towards the zone

to be excavated, while the central part of the excavations has to be undertaken on a thick layer of debris of tectonic

origins characterized by clusters of silted/sandy inconsistent conglomerated with massive boulders and stones of the

original rocks.

What it’s possible to observe is that we are excavating a deep trench on the core of a dramatically tectonically affected

area.

Even If it would have been an excavation of small entity the matter would still pose risks to be analyzed in details, as

we are considering a very deep trench that concern increasing volumes of rocks, implies the necessity to have very

clear ideas of the depth and the characteristic of the rock cluster. First of all should be analyzed the stability of the

slope sides, then the slope protection to be used must be evaluated.

Concerning the overall stability of the slopes sides should be pointed out that given the rocky nature of the material

and the high degree of fracturing, could be forecasted very fast collapses and slides, only the knowledge of the

geotechnical parameter of the cluster – all of its constituents and development- would allow the evaluation of the

fault planes along which potential slides, of big or small dimensions, may occur.

Concerning superficial slope protection, should be abandoned empiric methods and subjective solutions currently

implemented, to adopt scientific methods for the classification of the slope sides (for instance “Geomechanics Rock

Classification of Bieniawski”), in order to identify a methodology and the appropriate actions to be applied to this

purpose.

7. Station 35+250, share zone identified in the area with loose material and colluvium traces in the ground, change of slope inclination from the lower benches is required.






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