Construction Technology: Setting Out, Site Investigation, Excavation, and Foundations

Vocabulary flashcards covering building setting-out, site investigation desk and field studies, mechanical earthmoving equipment, trench timbering terminology, soil types, and foundation design principles.

Setting Out

The process of establishing and marking the exact physical boundaries, alignment, and demarcations of a proposed building on a site prior to construction.

Building Line

An imaginary boundary line established by the local authority beyond which the outer face or frontage of a building cannot extend toward a road or highway.

3:4:5 Principle

A geometric method using linear measurements in ratios of 3:4:5 (or multiples such as 6:8:10) to establish precise right-angled corners during site setting-out.

Profile Board

A temporary framework consisting of a horizontal timber rail secured to two driven vertical posts, used to mark excavation trenches, foundation centerlines, and wall positions.

Traveller

A T-shaped wooden sight rail cut to a specific length, used alongside profile boards and sight lines to verify and maintain uniform excavation depth along a trench.

Aspect

A site evaluation criterion that assesses the visual appearance, natural features, and overall habitability of a plot.

Prospect

A site selection criterion assessing future planned activities, environmental growth, and the likelihood of successful development on a given site.

Site Investigation

The systematic collection, recording, and reporting of ground and subsoil data needed to ensure safe, functional, and economical structural design and construction.

Desk Study

The preliminary non-intrusive phase of site investigation involving the review of Ordnance Survey maps, geological maps, mining history, utility locations, and planning records.

Field Study

The intrusive physical phase of site investigation involving surface appraisals, soil sampling, trial pits, boreholes, and in-situ ground testing.

Stationary Earth Moving Machines

Excavation machinery designed to operate from a fixed position, including face shovels, back actors, draglines, grabs, and trenching machines.

Mobile Earth Moving Machines

Heavy machinery capable of excavating or leveling earth while traversing across a site, including bulldozers, graders, scrapers, and loaders.

Planking and Strutting

A temporary system of timber or steel supports (also known as trench timbering) installed to prevent trench walls from collapsing during excavation.

Poling Boards

Vertical timber boards installed directly against the exposed soil surfaces of an excavation to prevent soil collapse.

Waling

Horizontal structural timbers running along the length of an excavation support system to hold poling boards in place and receive support from struts.

Struts

Horizontal timber or adjustable steel bracing members placed across the width of a trench to brace opposing walings or sheeting in position.

Bearing Capacity

The maximum load per unit area that subsoil can safely support without structural failure or excessive settlement, expressed in units like $kN/m^2$.

Cohesive Soils

Fine-grained subsoils such as clays and silts that expand when wet, shrink upon drying, and experience frost heave when pore water freezes.

Non-Cohesive Soils

Coarse-grained subsoils such as sands and gravels whose unconfined particles shear over each other at an angle of internal friction ($\Phi$).

Strip Foundation

A continuous shallow foundation type used to distribute load-bearing wall forces safely to underlying subsoil layers.

Deep Strip Foundation

A trench-fill strip foundation used at depths exceeding $1.2\,m$, filled with concrete nearly to ground level to eliminate the need for trench shuttering or timbering.

Pad Foundation

An isolated reinforced concrete foundation block designed to carry concentrated loads from individual structural columns.

Raft Foundation

A large continuous reinforced concrete slab spanning across the entire or partial footprint of a building to distribute structural loads over poor or variable subsoils.

Minimum Clearance of Damp-Proof Course (DPC) Above Ground

The standard requirement specifying that the damp-proof course (DPC) in external walls must be positioned at least $150\,mm$ above the finished ground level to prevent rising damp.

Cavity Concrete Fill Depth in Foundation Walls

The maximum height up to which mass concrete is poured inside a cavity wall trench, which must stop at least $225\,mm$ below the wall's damp-proof course (DPC).

Wall Damp-Proof Course (DPC) and Damp-Proof Membrane (DPM) Connection

The detail where the floor slab damp-proof membrane (DPM) is lapped over and sealed directly to the wall damp-proof course (DPC) on the inner leaf to form a continuous barrier against moisture.

Cavity Wall Substructure Construction

A wall type consisting of an inner leaf and an outer leaf separated by an air space, supported by strip foundations, and designed to support floor and roof loads while preventing moisture transmission.