chapter 5: soil particles, soil fabrics amd soil structures Flashcards
____ is the superficial unconsolidated mantle of disintegrated and decomposed rock material which is capable of supporting rooted plants.
soil
____ is a non-indurated aggregation of mineral and/or organic particles with air and/or water filled voids.
soil
_____ are primarily classified on the basis of a particle size.
soil
_____ is an easy parameter to measure and controls many aspects of the engineering are…
particle size
_____ is the dip in any direction from zero in the direction of strike to a maximum in the direction of true dip.
apparent dip
The measurement pf these properties by geologists is in terms of strike, measured as a whole compass bearing from north.
apparent dip
_____ are pronounced as bend or warped especially in sedimentary rocks.
folds
What are the three geometrical varieties of folds? ____
anticlines, synclines, monoclines
______ is the study of the form of the earth’s surface and the processes which sculpture it.
geomorphology
The external load or stress can produce on of three basic stress conditions acting on a unit cube of earth material: _____
compressive, shear, tensile
What are the seven types of retaining supports for rock slopes? _____
- concrete pedestal
- rock bolts
- concrete straps
- cable anchors
- wire meshes
- concrete impact walls
- shotcrete
- gunite
______ are used to support overhangs.
concrete pedestal
_____ are used to reinforce jointed rock masses.
rock bolts
_____ are used to support loose or soft rock zones.
concrete straps
_____ are used to reinforce thick rock masses.
cable anchors
_____ are restricted to falling blocks to movement along the face.
wire meshes
_____ are constructed along lower slopes to contain falling or sliding blocks.
concrete impact walls
_____ are used to reinforce loose fractured rock.
shotcrete
______ are similar to shotcrete except that the aggregate is smaller.
gunite
_____ are rapid to very rapid movement of incoherent mass of rock or soil-rock debris wherein the original structure of the formation is no longer discernible, occurring along an ill-defined surface.
avalanches and landslides
_____ are characterized by soil or soil-rock debris moving as a viscous fluid or slurry usually terminating at distances far beyond the failure zone.
flows
______ are characterized by a slow, imperceptible downslope movement of slope materials under low stress levels, which normally affects only the shallow portion of the slope, but it can be deep-seated where a weak zone exists.
creep
Construction of piers will generally be carried out by one of the three main methods: _____
- the use of cofferdam
- the use of open dredging caissons
- the use of compressed air-air caissons
Of the three main methods of construction of piers, ____ are most often used.
cofferdams
The common _____ consist of a single continuous wall on interlocking pilings, driven into the foundation strata.
cofferdam
The ____, aside from supporting part of the load that the piers of the bridge have to carry, shall often resist the earth pressure against the face and wing walls of the abutment structure.
abutments of a bridge
When no rock is available to serve as abutments foundation, the abutment shall be designed as a _______.
combination bridge piers and retaining walls
The seven requisite condition for reservoir site and dam site: ____
- water tight basin of ample size
- narrow outlet requiring a relatively small and economical dam having safe foundation
- opportunity for building a spillway to dispose the surplus water
- available materials for the construction of the dam
- assurance that the basin will not split up in too short time
- sufficient supply of water
- adequate reason to justify the cost of the project
The ____ is usually fixed as to convenience and economy rather than the character of the foundation.
location of a bridge
Accurate knowledge of subsurface at a building site include all information regarding the _____.
properties of the soil encountered
As a general rule, exploratory work of the foundation should be carried to a depth which at least _____ the width of the structure.
twice
Foundation loads may be transmitted to unconsolidated strata inn two ways: ____
- by constructing a continuous raft or spread footing or a system of isolated footings which rest directly on the surface stratum
- by forcing piles into the soil and joining uses structurally to the bearing column at the structures
The design of building foundation, and of all other foundations, consist of three essential steps: ___
- calculating the loads to be transmitted by the structure to the strata supporting
- determining the nature of the foundation beds that are to act as support
- designing the foundation structure to fit the conditions of loading and capacity of foundation beds
_____ are rarely due to faulty design of the foundation structure but rather to failure of the foundation beds to carry the loads put upon it.
foundation failures