20 June.2016.Building Tech-Chapter 5 Preliminaries

20 June 2016, Monday, 900am. Building Tech 1, Chapter 5 : Primilinaries

Topic : PRELIMINARIES

Preliminary inspection and survey of site, setting out of building.

Accommodation, storage and security

shallow excavation and timbering

The reconnaissance phose of a site investigation

• this site investigation is done through a site visit or walk over survey
• important evidences to look for are site lay out, surface condition, climate and hazards water levels.

Preliminary Investigation 
Preliminary investigation is aimed at predicting the geological stuctures, soil profiles and the position of ground water table by geophysical method or by making a few boreholes.
The investigation should give information on the existence on ground structures that may need closer examination : for example

• the extent of disturbed strata
• the location and extend of natural cvities and mine workings
• fractures and river crossing or alluvial areas that may have buried soft material or pet, their liability to cause subsidence, surface movements or instability
• information on suitability of solid for fills work, ground water condition and the possibility of flood should be provided at this stage

why water turn green?

Detailed investigation
at this stage, the extent of the tes, number and depth of boreholes, selectoin of appropriate qeuipmen for filed testing and the choic of laboratory testing are made.

solid exploration consists of 3 steps

1. boring and in-situ testing
2. sampling
3. laboratory testing

Monitoring

• motoring during construction and maintenance period is required whether the expectations of the proceeding investigation have been realize
• no one can ensure that the soil parameters used for design is the most representative of the soil conditions at the site unless the response is observed
• field observation can help for earlry diagnosis and redemption of any problem that might be encounters during construction
• among the measurement made during the monitoring stage are the settlement, displacement, deformation, inclination and pore water pressure.

Boring
soild boring s are the most common method of subsurface exploration in the field. A bore hold is used to determine the nature of the ground in a qualitative manner and then revocer disturbed and undisturbed samples for quantitative examination.

some types of borings are hand or mechanical auger borings, wash borings, percussion drilling, rotary drilling and core borings An auger is screw like tool used to bore a hold

some augers are operated by hand : others are power operated.

Boring Log

Contractors responsibility after being given possession and site layout plan and details drawings necessary

Commencing tasks

•  clearing the site
• setting out the building
• establishing a datum level 

http://www.dailymail.co.uk/news/article-3525219/Chinese-five-star-hotel-built-inside-quarry-100-yards-beneath-ground-level-Shanghai.html

some country require developer do day light analysis before the plan approved.

in the eye of fire engine, property owner should left 1 meter

Setting Out The Site
set up profile board after the main building lines

• should set up clear of the foundations tranceh positions to locate the trench, foundations and walls
• required at all trench and wall intersections