Exam 11: Soils and Excavations

Two methods are used to support earth pressure on a basement wall. In one of these, the basement wall supports the earth pressure and is commonly used where the site is much larger than the building's footprint to allow open excavations. The second method is used on a tight site, where the building's footprint covers the entire site or most of it. What type of excavation support system is used in the second method?

In one of the methods of constructing cantilevered soldier piles for excavation support, the (outer)face of the wall is covered with welded wire reinforcement (WWR)on which concrete is pressure sprayed. In another method, WWR and concrete are replaced by an alternative material. What is that material?

Which of the following is not used for excavation supports?

Of the four types of soils-gravel, sand, silt, and clay-which of them are considered cohesive soils and which are considered noncohesive soils?

The bearing capacity of a soil is generally expressed in terms of

Explain what engineered fill is.

What is the essential difference between contiguous bored piles (CBP)and secant piles as the excavation support system?

In terms of design and construction, secant piles are related to

Using sketches, explain the difference between cantilevered soldier pile and anchored soldier pile excavation support systems.

Explain where self- supporting basement excavation may be used.

If the bearing capacity of the soil is high, the footing area required is large.

In the soldier pile and lagging system, the lagging generally consists of

Explain why clayey soils are unstable.

Explain the difference between how a stiff, dense soil and a soft, loosely compacted soil perform during an earthquake.

Cohesive soils are those in which the dry soil particles tend to separate from each other when mixed with a small amount of water.

Construction site investigation consists of two parts: (i)surface investigation and (ii)subsurface investigation. Is investigating the site's natural drainage system and the site's likelihood to incur flooding a part of surface investigation or subsurface investigation?

The expansiveness of a soil is determined from the values of

Name two items of information that a subsurface investigation of site provides to determine the cost incurred in excavating for foundations and basements.

Explain why the wall and column footings must be placed below the frost line.

In which situation will the cantilevered soldier piles (as excavation supports)be provided with tieback anchors?