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II/ <br /> Mining and Elements of Production <br /> Earthmoving •Volume Measure • Swell <br /> • Load Factor • Material Density <br /> Volume Measure— Material volume is defined Bank=Loose_(1 +Swell)_ <br /> according to its state in the earthmoving process.The 1000 LCM-(1 +0.25)=800 BCM <br /> three measures of volume are: 1308 LCY_(1 +0.25)= 1046 BCY <br /> BCM(BCY) —one cubic meter(yard)of material Load Factor—Assume one bank cubic yard of <br /> as it lies in the natural bank state. material weighs 3000 lb. Because of material char- <br /> LCM(LCY) —one cubic meter(yard)of material acteristics,this bank cubic yard swells 30%to 1.3 loose <br /> which has been disturbed and has cubic yards when loaded,with no change in weight. If <br /> swelled as a result of movement. this 1.0 bank cubic yard or 1.3 loose cubic yards is com- <br /> CCM(CCY)—one cubic meter(yard)of material pacted,its volume may be reduced to 0.8 compacted <br /> which has been compacted and cubic yard,and the weight is still 3000 lb. <br /> has become more dense as a Instead of dividing by 1 + Swell to determine bank <br /> result of compaction. volume,the loose volume can be multiplied by the load <br /> In order to estimate production, the relationships factor. <br /> between bank measure,loose measure, and compacted If the percent of material swell is known, the load <br /> measure must be known. factor(L.F.)may be obtained by using the following <br /> Swell—Swell is the percentage of original volume relationship: <br /> (cubic meters or cubic yards)that a material increases 100% <br /> L.F. _ <br /> when it is removed from the natural state. When exca- 100%+%swell <br /> vated,the material breaks up into different size particles Load factors for various materials are listed in the <br /> that do not fit together,causing air pockets or voids to Tables Section of this handbook. <br /> reduce the weight per volume. For example to hold the To estimate the machine payload in bank cubic <br /> same weight of one cubic unit of bank material it takes yards, the volume in loose cubic yards is multiplied by <br /> • 30%more volume(1.3 times)after excavation. (Swell the load factor: <br /> is 30%.) <br /> Loose cubic volume Load(BCY)=Load(LCY) x L.F. <br /> for a given weight The ratio between compacted measure and bank <br /> 1 +Swell = measure is called shrinkage factor(S.F.): <br /> Bank cubic volume for <br /> the same given weight S F = Compacted cubic yards(CCY) <br /> Loose Bank cubic yards(BCY) <br /> Bank = (1 +Swell) Shrinkage factor is either estimated or obtained from <br /> Loose=Bank X (1 +Swell) job plans or specifications which show the conversion <br /> from compacted measure to bank measure. Shrinkage <br /> Example Problem: factor should not be confused with percentage com- <br /> paction(used for specifying embankment density,such <br /> If a material swells 20%,how many loose cubic meters as Modified Proctor or California Bearing Ratio[CBR]). <br /> (loose cubic yards)will it take to move 1000 bank cubic Material Density—Density is the weight per unit <br /> meters(1308 bank cubic yards)? volume of a material. Materials have various densities <br /> Loose=Bank X (1 +Swell)= depending on particle size,moisture content and varia- <br /> 1000 BCM x (1 +0.2)= 1200 LCM tions in the material.The denser the material the more <br /> 1308 BCY X (1 +0.2)= 1570 LCY weight there is per unit of equal volume.Density estimates <br /> How many bank cubic meters(yards)were moved if are provided in the Tables Section of this handbook. <br /> a total of 1000 loose cubic meters(1308 yards)have Weight = kg(lb) <br /> o Density= <br /> been moved?Swell is 25%. Volume m3(yd3) <br /> Weight= Volume X Density <br /> • 25-2 <br />