Foundation Types and Considerations
24 Questions
11 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the formula for calculating average load per meter run of wall?

  • Height/Total load
  • Total load/Height
  • Total load/Area
  • Perimeter/m (correct)

Which factor is most crucial for ensuring the foundation does not experience shear failure?

  • Width of the foundation (correct)
  • Depth of the foundation
  • Type of concrete used
  • Site location

What initial operation should be performed at the construction site before foundation work begins?

  • Lay the concrete foundation
  • Clear existing structures
  • Secure the site (correct)
  • Begin wall construction

When excavating trenches for foundations, which equipment is typically used?

<p>Excavator (A)</p> Signup and view all the answers

How should the site engineer ensure the foundation lines are accurately set before excavation?

<p>Employ profiles and string lines (D)</p> Signup and view all the answers

What should be securely established to safeguard the construction site?

<p>Lockable gates (A)</p> Signup and view all the answers

What is a primary consideration when determining the concrete finish for foundations?

<p>Finish accuracy for level (D)</p> Signup and view all the answers

Which type of foundation is appropriate for buildings with shallow depth requirements?

<p>Strip foundation (A)</p> Signup and view all the answers

Which of the following is the primary purpose of a foundation?

<p>To safely transfer the load of the building to the subsoil (D)</p> Signup and view all the answers

What is one of the critical factors to consider in foundation selection related to ground conditions?

<p>Bearing capacity of the ground (A)</p> Signup and view all the answers

What kind of soil presents the most challenges in foundation construction?

<p>Clay (B)</p> Signup and view all the answers

In assessing site conditions for foundation design, what type of survey is typically conducted?

<p>Site and soil survey (D)</p> Signup and view all the answers

How does the depth of good strata influence foundation design?

<p>It affects the structural load capacity (D)</p> Signup and view all the answers

What is a consideration when evaluating the construction near trees?

<p>Distance to grow roots affecting foundation stability (D)</p> Signup and view all the answers

What is the average loading for a two-storey domestic dwelling constructed traditionally?

<p>30 – 50 kN/m (A)</p> Signup and view all the answers

Which of the following factors does NOT influence the selection of a foundation type?

<p>Type of insulation used (D)</p> Signup and view all the answers

Which type of foundation is primarily used for areas with poor soil conditions?

<p>Raft foundations (B)</p> Signup and view all the answers

What is a major reason for using pile and beam foundations?

<p>Low bearing capacity of subsoil (D)</p> Signup and view all the answers

When would mass concrete foundations be considered uneconomical?

<p>When building loads are high (A)</p> Signup and view all the answers

What foundation type is ideal when differential settlement might occur?

<p>Raft foundation (B)</p> Signup and view all the answers

How far should buildings near trees be positioned according to NHBC Standards?

<p>At least 1.5 times the height of the tree (D)</p> Signup and view all the answers

What is the primary benefit of using trench blocks in substructure walls?

<p>Improved structural integrity (B)</p> Signup and view all the answers

What indicates that substructure walls are ready for backfill?

<p>Cavity fills are completed and voids for services are noted (A)</p> Signup and view all the answers

What should be evaluated when considering the bearing capacity of soil for foundation design?

<p>Presence of compressible layers (D)</p> Signup and view all the answers

Flashcards

Strip Foundation

A type of foundation used for supporting walls, typically on firm ground like rock, gravel, or dense sand.

Pile Foundation

A foundation using piles driven deep into the ground, suitable for soft soil or large loads.

Bearing Capacity

The maximum pressure the soil can withstand without failing.

Foundation Design

The process of choosing and designing a foundation based on the soil type, structure, and location.

Signup and view all the flashcards

Pad Foundation

A foundation used primarily for columns with concentrated loads.

Signup and view all the flashcards

Raft Foundation

A large, continuous foundation used when soil bearing capacity is low or differential settlement is a concern.

Signup and view all the flashcards

Pile and Beam Foundation

A foundation using piles supported by a horizontal beam, often used in challenging soil conditions.

Signup and view all the flashcards

High Water Table

A water level close to the ground surface.

Signup and view all the flashcards

Construction Site Preparation

Protecting boundaries, removing topsoil for later use.

Signup and view all the flashcards

Two-Storey Domestic Dwelling

Average foundation load for a typical two-storey house. Usually between 30–50 kN/m2

Signup and view all the flashcards

Seasonal Movement

Fluctuations in soil levels due to moisture changes (e.g., clay)

Signup and view all the flashcards

Clay Soil

Soil type that experiences significant, seasonal movement.

Signup and view all the flashcards

Hardcore

Strong base material (e.g., MOT 1/2) used in foundation construction.

Signup and view all the flashcards

Subsoil

The layer of soil below the surface.

Signup and view all the flashcards

Ground Conditions

The characteristics of the soil, influencing the appropriate type of foundation.

Signup and view all the flashcards

Foundation Levels

Checking the horizontal accuracy of excavated foundations before pouring concrete.

Signup and view all the flashcards

Trench Blocks

Building blocks for substructure walls within excavated trenches.

Signup and view all the flashcards

Excavate Trenches

To dig trenches for foundations using appropriate equipment.

Signup and view all the flashcards

Mass Concrete Foundations

Concrete foundations used for supporting high building loads

Signup and view all the flashcards

Tree Proximity

Distance from a building to trees, especially considering soil type and tree size (NHBC guidelines).

Signup and view all the flashcards

Minimum Tree Distance

Building should be 1.5 times the tree's height away from trees in rows.

Signup and view all the flashcards

Study Notes

Foundation Types

  • Strip foundations are commonly used on firm ground like rock, gravel, dense sand, or stiff clay
  • Wider strip foundations are needed on softer ground like clay or sandy clay
  • Pile foundations are used when traditional foundations are not suitable due to low bearing capacity, made-up ground, high water table, high moisture movement, or compressible soil layers

Foundation Considerations

  • The average load for a traditional two-storey domestic dwelling is between 30 - 50 kN/m2
  • Foundation design depends on ground conditions, structure, location, and cost
  • Factors related to ground conditions that impact foundation selection include bearing capacity, depth of good strata, composition of the ground, ground level, and gradients

Construction Sequence

  • Secure the construction site and establish clear boundaries
  • Strip the topsoil and store it for landscaping at project completion
  • Deliver hardcore (MOT type 1 or 2) to the site
  • Spread and compact base material for a working surface
  • Set out foundation lines using string lines, profiles, or coordinates
  • Excavate trenches using appropriate equipment
  • Inspect foundation levels before pouring concrete
  • Substructure walls can be built with trench blocks or cavity blockwork

Foundation Problems

  • Foundations cast on clay must account for seasonal movement caused by moisture content changes in the clay

Pad Foundations

  • Pad foundations are often used for columns.
  • Mass concrete foundations may be used where building loads are high.
  • If loads are high, reinforcement is needed.

Raft Foundations

  • Raft foundations are used when the bearing capacity of the soil is low or differential settlements may occur.

Pile and Beam Foundations

  • Pile and beam foundations are used where traditional strip foundations are not suitable, particularly in the cases of:
    • Low bearing capacity of the subsoil
    • Made-up ground
    • High water table
    • High moisture movement of the subsoil
    • Presence of highly compressible layers such as peat.

Building Near Trees

  • Building near trees can cause problems with foundations, especially in clay soils.
  • The NHBC Standards provide recommendations for identifying hazards and ensuring satisfactory foundation construction.
  • Where trees are in rows, the minimum distance from the building should be 1.5 times the height of the tree.

Learning Outcomes

  • Understand the different types of foundations
  • Understand the relationship between ground conditions and types of foundations
  • Appreciate the considerations for building near trees

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Foundations PDF

Description

Explore the various types of foundations used in construction, including strip and pile foundations. Understand the considerations involved in foundation design based on ground conditions and structural loads. This quiz covers essential construction sequences and factors affecting foundation selection.

More Like This

Types of Foundation in Construction
12 questions

Types of Foundation in Construction

SumptuousRainbowObsidian avatar
SumptuousRainbowObsidian
Types of Shallow Foundations - Spread Footings
30 questions
Concrete Frame Structures Foundations
8 questions
Use Quizgecko on...
Browser
Browser