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BSS502BSS502CONSTRUCTION TECHNOLOGY 1CONSTRUCTION TECHNOLOGY 1

PURPOSEPURPOSETo determine the site’s suitability for building and the nature and the extent of preliminary work that will be needed

Why it is important?It will shows the detailed to many physical aspect such as subsoil composition, demolition and the legal aspect such as planning permission, right of access and preservation order

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OBJECTIVESOBJECTIVES• To assess the general suitability of

the site with the proposed works• To help produce a design which is

adequate and economic• To help overcome possible

difficulties & delays that may arise during construction period due to ground and other local conditions

• To predict possible changes that may occur/cause of all changes in site condition

• To maximize potential of the site

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DESCRIPTIONDESCRIPTION

A combination process which range from looking at published information such as maps to arrange laboratory test on the soil

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Information required from a site Information required from a site investigation:investigation:a. Information affecting the design

of the structure: shear strength and compressibility of the soil

b. Information affecting the construction of the works: the extent and properties of material to be excavated, or to be used for fill or for road bases or concrete aggregates

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Information required from a site Information required from a site investigation:investigation:c. Information on ground water

conditions: the level and seasonal variation of the water table, the pressures in the soil water, and the permeability of the soil.

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Planning an investigation:Planning an investigation:• In the earlier stages of an

investigation, the information available is often inadequate to allow a detailed plan to be made.

• The investigation must therefore proceed in 3 stages:

1. Desk study2. Site reconnaissance3. Detail Examination of Tests and

Programs

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK

1. Site Location Nearest town and city Schools, emergency services,

entertainment, recreation, shops, transport and employment

Distance from head office (client & builders) & traveling time

Distance from nearest railway station to the site

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK2. Accessibility Approach and site access roads,

width, gradient, bends, sharp corners, condition and construction relative to transport heavy plant and equipment

Bridges, strength, width and clearance height

Temporary roads, rolled metal tracts or consider preparing sub base for new roads as temporary access

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK3. Availability of spaceSite offices, canteen, stores and

compoundMaterial storage areas and

handlingConstruction area and assembly

areasPlant location

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK4. Services Water, drainage, electricity, gas

& telephoneLocation will be determined from

maps by consultation with the appropriate local authorities

An estimate of buildings usage is also for ascertaining the demand on sewers and drains

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK5. Ground composition Boreholes are required to

determine :Changes in strataStrength of subsoilToxicity of subsoilStability of excavationWater table (depth below

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECK6. Site clearance and demolition

A plan of the site should indicate trees, shrubs and existing buildings and a site survey will reveal the extent of necessary leveling Demolition and excavation

Method and costEffect of trees and structural

prevention orders

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INFORMATION/ISSUES TO INFORMATION/ISSUES TO CHECKCHECKReuse of materialsProtection of adjacent buildingSpecial insurance requirementCompensation payment and

liability for damageDistance to spoil tips and charge

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IN GENERAL…IN GENERAL…• Dealt with local planning authority to

ascertain whether there are special/significant restrictions which could adversely affect the development of site building line position

• Survey should include details of neighboring development, future development and the position with regard to facilities in the area

• Should enquire the existence of any restrictive covenants such as right of way, light & drainage which may restrict the development

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THE PROCESSTHE PROCESS• Desk Study• Site Reconnaissance/ Walk over

survey• Preliminary report or feasibility study• Preliminary Ground Investigation -

Planning of main Preliminary report• Main Ground Investigation• Laboratory testing• Financial Report (Return of

Investment)• Final report

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DESK STUDIESDESK STUDIES• It is important to collect all

available information about the site before starting work.

• A desk study is the collation and review of information already available about a site, and is carried out at an early stage of site appraisal to inform and guide the remainder of the site investigation.

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DESK STUDIESDESK STUDIES• Collect as much material as

possible about the site such as-Maps (geological, ordinance

survey, etc)Air photographGeological books & journalMining records & reports of

previous site investigationLibrary, news paper, adjacent

buildings, etc.

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DESK STUDIESDESK STUDIES

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SITE RECOINAISSANCE / WALK SITE RECOINAISSANCE / WALK OVER SURVEYOVER SURVEY

The initial document search should be followed by a walk-over survey of the site and its surroundings.

This should be a methodical examination of the site, based on defined classes of information, which complements the desk study and typically provides valuable information on matters such as:

Topography: indications of slope instability, spoil heaps or signs of ground subsidence resulting from mining.

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SITE RECOINAISSANCE / WALK SITE RECOINAISSANCE / WALK OVER SURVEYOVER SURVEY

Geology: exposures of soils and rocks which can be examined and sampled.

Surface water and ground water: signs of flooding; springs; water logging

Vegetation: signs of vegetation die-back or restricted vegetation as a result of

contamination of the ground; presence of invasive species such as Japanese Knotweed; trees which may cause shrinkage and swelling of clay soils.

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SITE RECOINAISSANCE / WALK SITE RECOINAISSANCE / WALK OVER SURVEYOVER SURVEY

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The invasive root system and strong growth can damage foundations, buildings, flood defences, roads, paving, retaining walls and architectural sites. It can also reduce the capacity of channels in flood defenses to carry water

SITE RECOINAISSANCE / WALK SITE RECOINAISSANCE / WALK OVER SURVEYOVER SURVEY

Ecology: indicators of protected species, newts, badgers, bats, nesting birds.

Contamination: indications of spills, disturbed ground, areas of fill or spoil heaps, old fuel or oil tanks.

Structures: settlement of existing structures or the use of asbestos; indicators of archaeological value.

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SITE RECOINAISSANCE / WALK SITE RECOINAISSANCE / WALK OVER SURVEYOVER SURVEY

Local Knowledge: anecdotal information on past uses of the site or past problems in the area.

Access & services: information such as access for site equipment and location of buried or overhead services

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DETAIL EXAMINATION OF DETAIL EXAMINATION OF TESTS AND PROGRAMS/ TESTS AND PROGRAMS/ DETAILED EXPLORATIONDETAILED EXPLORATION

The principal objectives of the detailed soil

test/investigation are as follows:a. To determine in detail the geological

structure of the site, including the thickness, sequence and extent of the strata.

b. To determine the ground water conditions

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c. To obtain disturbed and undisturbed samples for identification and laboratory testing

d. To carry out tests to determine the mechanical properties of the soil insitu

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DETAIL EXAMINATION OF TESTS DETAIL EXAMINATION OF TESTS AND PROGRAMS/ DETAILED AND PROGRAMS/ DETAILED EXPLORATIONEXPLORATION

There are two principal methods of investigating the ground conditions, trial pits and boreholes

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DETAIL EXAMINATION OF TESTS DETAIL EXAMINATION OF TESTS AND PROGRAMS/ DETAILED AND PROGRAMS/ DETAILED EXPLORATIONEXPLORATION

GROUND INVESTIGATIONGROUND INVESTIGATIONTrial Pits Trial pits are shallow excavations

going down to a depth not greater 6m.

The trial pit as such is used extensively at the surface for block sampling and detection of services prior to borehole excavation.

Can be dug by hand or mechanical excavator

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GROUND INVESTIGATIONGROUND INVESTIGATIONTrial Pits Only suitable in dry area as they

allow hand cut samples to be taken which minimize the disturbance of sample

Most suitable use in exploring back filled area and sites overlain by variable natural deposits

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GROUND INVESTIGATIONGROUND INVESTIGATION

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GROUND INVESTIGATIONGROUND INVESTIGATION

Boreholes• A borehole is used to determine the

nature of the ground (usually below 6m depth) in a qualitative manner

• Recover undisturbed samples for quantitative examination. Where this is not possible, for in gravelly soils below the water table, in-situ testing methods are used.

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GROUND INVESTIGATIONGROUND INVESTIGATION• Obviously the information gained from

a borehole is an extremely limited picture of the subsurface structure. It is therefore essential to compare the results obtained with those that could have been expected from the desk study. The greater the number of boreholes the more certain it is possible to be of the correlation and thus to trust in the results.

• The two principal types of boring machine used for Site Investigation which is light percussive and drilling machines.

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GROUND INVESTIGATIONGROUND INVESTIGATION

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TASK 1Your team are appointed as a project leader to a proposed mix development project in Sri Iskandar, Perak. The site is located on existing 300 acre of ex-mining area. You are required to conduct the site exploration according to phase by phase. Assumption can be made to suit to your project and site.(1 hour task, 30 minutes for presentation)