CM 2113 WANG TEST 2 FINAL EXAM 2025

CM 2113 WANG TEST 2 FINAL EXAM 2025 Three basic components of soil - -solid particles, water and air (T/F) For bulk materials, volumetric measure varies with material's position in the construction process - -T (T/F) The same weight of a material will occupy different volumes as the material is handled on the project - -T Swell - -Reduction in density due to loosening the soil by digging Which soil volume is used to determine the volume capacity of excavating/hauling equipment? - -Loose Volume Soil density is a measure of ? per unit of volume. - -Weight What is soil's bank condition? - -Typical amount of soil in its natural state (T/F) 1 bank cubic yard is 1 cubic yard of material after it has been disturbed by a loading process - -F What are construction costs based on? - -(total quantity of the work to be done)*(the unit price of the work) Rolling Resistance - -resistance of a level surface to constant-velocity motion across it What does rolling resistance result from? - -friction of the driving mechanism, tire flexing and the force needed to push through or ride over the supporting surface (T/F) rolling resistance applied to both crawler-type and wheel-type mobile equipment - T (T/F) When a vehicle moves down a grade the force of gravity that assists the vehicle is also called grade assistance - -T (T/F)power required, total resistance and effective grade all denote the same thing - -T CM 2113 CM 2113 CM 2113 (T/F) The decision process for matching the best possible machine to the project task requires the engineer to take into account both the properties of the material to be handled and the mechanical capabilities of the machine - -T (T/F) The power to move a crawler type of tractor and load is called Rimpull - -F Bank Soil - -natural state, before being undisturbed used for performing quantity take offs Loose Soil - -has been excavated or loaded, used to determine the volume capacity of the excavating and hauling equipment Compact Soil - -after comparison, used to determine the volume of any structure such as a damn or a fill when excavated, a soil increases in ______________due to loosened soil grains and void spaces filled with air - -volume when a soil is ____________, some of the air is forced out of the soil's void spaces - compacted Total Resistance= - -grading resistance +rolling resistance Total Effective Grade= - - Moister content calculation - -(wet weight - dry weight) / dry weight Speed - -affects cycle time Cycle time - -drives production Production - -determines cost Grade Resistance Factor= - -(20 lb/tn) * (%grade) Coefficient of traction - -the ratio between the maximum amount of pull a machine exerts before slippage and the total weight on the drivers Usable Force - -(coefficient of traction) * (weight on powered running gear) Typical soil Volume Change During Earthmoving? - -Bank 1.0 Lose 1.25 Compacted 0.90 CM 2113 CM 2113 the primary factors thatdetermine the power available at the drive wheels (drawbar) of a machine are? - -Engine horsepower and operating gear Maximum usable tractive force= - -=F x CT (F= load on drive axles in pounds- CT = coefficient of traction) LCY= - -[Vc(1+%swell)]/(1-% shrinkage) BCY= - -Vc/(1-%shrinkage) BCY to LCY - -Vl=Vb(100%+%swell) Total Resistance Force= - -RRF+GRF (downhill=RRF-GRF) Total effective grade down= - --%grade + (RR factor/20) TEG up= - -%grade+ (RR factor/20) Usable Power depends on what? - -project conditions Underfoot conditions determine what? - -how much of the available power can be transferred to the surface to propel the machine To Increase or Decrease Moisture Content= - -water deficiency/ 8.34 Water Deficiency= - -(final %-initial %)(dry)(27) Truckload Haul Example= - -[Vb*(1+%swell)]/truck load capacity Earthmoving - -is the process of moving soil or rock from one location to another and processing it so that it meets construction requirements of location, elevation, density, moisture content, and so on. Ex: excavating,loading,hauling,spreading,compacting, and grading Three-link Earthwork System - -Excavate and load --> haul, dump, and return --> spread and compact Planning earthwork construction - -review contract documents, study the plans, plan the work, perform quantity take-off, determine costs After the site visit is completed, the planner determines the quantity. of materials that will have to be furnished or moved. - -takeoff or quantity survey Quantity takeoff - -must be as accurate as possible, and should be based on all available engineering design data CM 2113 CM 2113 During takeoff the planner must make decisions concerning - -equipment needs, sequence of operations, and crew size Density - -most common used parameter for specifying construction operations bc there is a correlation between a soil's physical properties and density Unit soil - -pounds per cubic foot, density:pounds per cubic yard,kg per cubic meters Soil gradiation - -the distribution in (%) by weight, of individual particle sizes Organic soils - -remove before building Non-cohesive soils - -well rounded, subangular, subrounded, angulatr, (bulk shaped soil grains) Cohesive - -platy shaped soil grains. (small grained <#200 mesh sieve Unit weight - -total weight/total volume (w/v) Dry unit weight - -weight of solids/total soil volume (ws/v) Water content - -weight of water in soil/weight of soil solids (ww/ws) Dry unit weight - -yd= y/(1+water content) Bank - -material in its natural state before disturbance (bcy) bank cubic yard Loose - -material that has been excavated or loaded (lcy) loose cubic yard Compacted - -material after compaction (ccy) compacted cubic yard Bank volume is used when - -determining the volume of material to be excavated. This is the unit of measure for quantity take off from drawings Loose volume is used - -to determine the volume capacity of excavating and hauling equipment Compact volume is used - -to determine the volume. Of any earth structure such as a dam or fill. It represents volume after the required compactive effort has been applied. Rolling resistance - -is a measure of the force (lb/ton) that must be overcome to rotate a wheel over the surface on which it makes contact. It is called by internal friction and tire flexing. Ex. A tire penetrating the surface CM 2113 CM 2113 Grade resistance - -represents that component of vehicle weight which acts parallel to an inclined ver run Gr factor - -20lb/ton Grade assistance - -gravity assists the machine when traveling down grade Totat resistance factor= - -RRF+GRF or RRF-GAF Primary factors for power - -engine horsepower and operating gear Horsepower - -33,000 ft-lb Drawbar pull - -the power to move a crawler tractor and load. Crawler tractor must generate more drawbar pull than total resisting force acting against it Rimpull - -power to move a wheeled piece of equipment and its load. Pushing force exerted by the tires against the ground surface Coefficient of traction - -factor that determines the maximum possible tractive force between the powereeed running gear of a machine and the surface of which it travels. If the coeeeficient of traction is sufficiently high - -there will be no slippage Usable power depends on - -haul road surface, condition, and temperature Most turbocharged engine machines will operate at altitude of what before they lose power? - -2500 Rolling resistance applies to both crawler-type and wheel-type of mobile equipment. - true When a vehicle moves down a grade, the force of gravity that assists vehicle movement is also called grade - -true Power required, total resistance, and effective grade all denote the same thing. - -true The power to move a crawler type of tractor and load is called rimpull. - -false Is a reduction in density due to loosening the soil by digging. - -swell Which of the following soil volume is used to determine the volume capacity of excavating and hauling equipment? - -loo