Lecture 10: CE Applications Flashcards
CE applications of Geology
• Foundation • Excavation • Tunnelling • Dams and Reservoirs • Construction Materials • Slope Stability (Discussed in Geol Hazards as application and hazard)
COARSE GRAINED SOIL
– it means that majority of its particles are
bigger or on the coarser range of soil sizes
FINE GRAINED SOIL
– majority of the particles are on the finer side
COHESIONLESS SOIL
it means that the soil does not “stick”
together and cannot oppose pulling forces (think sand, if you try
to pull sand apart, there is no resistance and it just pulls apart)
COHESIVE SOIL
it means that the soil can oppose pulling forces
think clay, you can try to pull apart clay but it has resistance
The bottom part of a structure that serves to transfer the load of the structure to the Earth
Foundation
The soil/rock directly beneath the
foundation
Foundation Bed
The goal of a foundation
to transfer the load safely to the ground (ground does not give or collapse) and without too much
deformation (too much deformation means that the
purpose of the structure is no longer served efficiently)
2 limits in Designing Foundation
1 Strength Limit
2 Serviceability Limit
the limit when one part breaks due to
too much load.
Strength Limit
the limit related to the function
or useability of an object.
Serviceability Limit
For foundations, the relative parameters for strength limit and serviceability limits are
1 Foundation Capacity
2 Settlement
the maximum load that the foundation, based on its dimensions and soil supporting it, can carry
FOUNDATION CAPACITY
the amount of “sinking” that will happen to a
foundation (and hence the structure) once the loads of the structure are in place.
SETTLEMENT
2 Types of Settlement
1 Typical
2 Differential
settlement is the same for all points
of structure, hence the structure simply “sinks”.
Typical Settlement
settlement is different for different points of the structure, hence it may seem to “sink” and “rotate” at the same time.
Differential Settlement
Settlement that can lead to distortion damages to the structure
Differential
Settlement is not much of a limiting value when the foundation sits on_________
Rock
2 Parts of Settlement Foundation
1 Immediate
2 Consolidation
settlement that happens while
it is being constructed or immediately after
Immediate
settlement that happens over a long period of time. Way after the structure has been constructed, settlement still happens. This happens due to clays not allowing water to be expelled quickly, hence, it loses water over time, and as it does, it settles more.
Consolidation
DENSELY packed soils will allow __________ to happen compared to loosely packed soils.
less settlement
Is the ability of cay soils to hold water a good or a bad thing?
this is bad since it can take years before the building is able to force the water out in between clay minerals and this will result to settlement of clay over a long
period of time. This means that if your building is on clay, after a few years, you will find your building still sinking into the ground.