Question 1

The loadbearing capacity of a soil is mainly influenced by its&#10;A) Density&#10;B) Porosity&#10;C) Angularity&#10;D) Toxicity&#10;E) Plasticity

Accepted Answer

The loadbearing capacity of a soil mainly depends on its density because denser soil can bear more load than less dense soil. Porosity, angularity, toxicity, and plasticity can affect other properties of the soil but not its load-bearing capacity.

Question 2

Settlement in soils is mainly caused by&#10;A) A chemical reaction between the soil particles&#10;B) An upward expansion of soil due to heating&#10;C) A downward compression of soil due to loading&#10;D) A lateral sliding of soil due to freezing&#10;E) A swelling of soil due to water pressure

Accepted Answer

Settlement in soils is mainly caused by a downward compression of soil due to loading. This could be due to the weight of a building or any other structure built on the soil. The weight of the structure compresses the soil particles, causing settlement over time.

Question 3

The primary function of a foundation is to provide&#10;A) A base for the external wall&#10;B) A means for the building loads to be transferred to the ground&#10;C) Stability to the ground&#10;D) An entry point for services to the building&#10;E) A partition between different types of soil

Accepted Answer

The primary function of a foundation is to transfer the weight of the building to the ground and provide stability, making option B the best choice. The other options may be secondary functions of a foundation, but the primary function is load transfer and stability.

Question 4

Strip foundations are generally placed a minimum of 750mm below ground level because they are:&#10;A) Less affected by climatic conditions at this level&#10;B) Less affected by atmospheric conditions at this level&#10;C) Less affected by biological conditions at this level&#10;D) Less affected by chemical conditions at this level&#10;E) Less affected by environmental conditions at this level

Accepted Answer

Strip foundations are placed at a minimum of 750mm below ground level to avoid the effects of frost heave and other climatic conditions that can affect the stability of the foundation.

Question 5

A raft foundation is generally used when&#10;A) A strip foundation would be too narrow&#10;B) A short bored pile foundation would be too shallow&#10;C) The soil is too heavy to excavate&#10;D) The soil is too light to excavate&#10;E) The soil bearing capacity is very low

Accepted Answer

A raft foundation is used when the soil bearing capacity is very low, as it spreads the load over a large area to reduce pressure on the soil.

Question 6

A short bored pile foundation works by transferring the building load&#10;A) To a good loadbearing strata&#10;B) To a poor loadbearing strata&#10;C) To the water table&#10;D) Over a wide area of the site&#10;E) From a non-cohesive to a cohesive soil

Accepted Answer

Short bored pile foundation works by transferring the building load to a good loadbearing strata. This is achieved by drilling a borehole into the ground, inserting a steel reinforcement cage, and then filling the borehole with concrete. The load is then transferred from the building to the pile and then to the good loadbearing strata.

Question 7

The thickness of a 600mm wide strip foundation supporting a 250mm wide loadbearing wall should be&#10;A) 145mm&#10;B) 150mm&#10;C) 160mm&#10;D) 175mm&#10;E) 200mm

Accepted Answer

The answer of The thickness of a 600mm wide strip...

Question 8

The width of a strip foundation supporting a load of 35 KN/m on a soil with a loadbearing capacity of 120 KN/m² and having a factor of safety of 1.5, should be A) 194mm B) 292mm C) 343mm D) 437mm E) 515mm

Accepted Answer

To find the width of the strip foundation, use the formula: Width = Load / (Safe bearing capacity). The safe bearing capacity is the loadbearing capacity divided by the factor of safety: 120 KN/m² / 1.5 = 80 KN/m². Therefore, Width = 35 KN/m / 80 KN/m² = 0.4375 m or 437 mm.

Question 9

A wide strip foundation can be prevented from failing under load by adding&#10;A) Steel reinforcement in the bottom&#10;B) Steel reinforcement in the top&#10;C) A greater amount of sand to the concrete mix&#10;D) A greater amount of water to the concrete mix&#10;E) A greater amount of lime to the concrete mix

Accepted Answer

Steel reinforcement in the bottom of the foundation adds strength and stability, preventing failure under load. Adding steel reinforcement to the top would not provide the same level of support, and adding more sand, water, or lime to the concrete mix would not directly address the issue of load-bearing capacity.

Question 10

Trees growing close to buildings can be a problem because the roots&#10;A) Can grow into the foundations&#10;B) Can destroy the foundations by taking the nutrients from the concrete&#10;C) Take water from the soil around the foundations&#10;D) Produce chemicals that corrode the concrete in foundations&#10;E) Cause the concrete in the foundations to expand

Accepted Answer

The answer of Trees growing close to buildings can be...

Deck 5: Foundations