外文翻译2土木工程.doc

Planimeter A planimeter is a mechanical device that is used to move a tracing point around the perimeter of the plotted area.It provides a value that is then multiplied by the square scale of the figure to calculate the figures area.A planimeter can be used on any figure no matter how irregular the figures shape might be.测面器，求积仪测面器是一个机械设备,用来移动围绕一个跟踪点绘制周边地区。它提供了一个值，这个值就是由该图的平方乘以比例值来计算出图形的面积。求积仪可以用于计算任何图形的面积，无论这个图形的面积有多么的不规则。 Trapezoidal Computations The mathematics of the area computations is often based on dividing the cross section drawing into parts.The computer can easily subdivide a cross section drawing into a large number of strips,calculate the area of each strip,and then sum the individual area to arrive at the area of a section.If the calculations must be made by hand,the area formula for a triangle and a trapezoid are used to compute the volume.梯形计算 数学上对于一个面积的计算通常是基于把整体分成若干份的剖面，计算机可以很容易地划分成若干条大跨剖面图，计算出每个条带区域，然后总结出每个地区到达的截面面积。如果计算必须由手工进行，那么可以使用三角形和梯形的面积计算公式。 Area of a triangle = 1/2 hw 4.1where h = height of the triangle w = base of the triangle 三角形面积=1/2 h * w h =三角形的高 W=三角形的底长 Area of a trapezoid = ( h1 + h2 )/2 * w 4.2where (see Fig.4.6) w = distance between the two parallel sides h1 and h2 = the lengths of the two parallel sides梯形的面积 = ( h1 + h2 )/2 * w W=两条平行边之间的距离h1和h2=两条平行边的长度The general trapezoidal formula for calculating area is Area = ( h0/2 + h1 + h2 + + h n-1 + h n/2 ) * w 4.3where (see Fig.4.6) w = distance between the two parallel sides h0hn = the lengths of the indivedual adjacent parallel sides 梯形面积的一般计算公式是 面积 = ( h0/2 + h1 + h2 + + h n-1 + h n/2 ) * w The precision achieved using this formula depends on the number of subdivisions,but is about ±0.5%.In the case of hillside construction,there can be both a cut area and a fill area in the same cross section (Fig.4.7).When making area computations,it is always necessary to calculate cut and fill areas separately.根据大量的实验证明，该公式的精度的误差大约是±0.5%.至于山坡施工，既可以是一个最大面积的梯形也可以是一个横截面积相同的梯形。当进行面积计算时，始终是挖填区分开计算。Average End Area The average-end-area method is most commonly used to determine the volume bounded by two cross sections or end areas.The principle is that the volume of the solid bounded by two parallel,or nearly parallel,cross sections is equal to the average of the two end areas times the distance between the cross sections along their centerline (see Fig.4.8).平均端面积法平均端面积法是最常用来确定两个截面或截面范围内的地区面积。其原理是固体量由两个平行，或近于平行，截面界等于高端领域的两个时间的平均值之间的横截面沿其中心线的距离来确定的。The average-end-area formula is Volume net cubic yards(cy) = (A1 + A2)/2 * L/27 4.4 where (see Fig.4.8).A1 and A2 = area in square feet(sf) of the respective end areas L = the length in feet between the end areas平均端面积公式 体积网立方码 = (A1 + A2)/2 * L/27 A1和A2 =高端领域的平方英尺的面积L为长度在高端领域之间的脚 The principle is not altogether true because the average of the two end areas is not the arithmetic mean of many intermediate areas.The method gives volumes generally slightly in excess of the actual volumes.The precision is about ±1.0%.其原理是不完全正确的，因为这两个高端领域的平均不一定是算术平均数的中间领域。该方法给出了一般略有过剩的实际数量的计算方法，精度为± 1.0。 Although cross sections can be taken at any conservative interval along the centerline,judgment should be exercised,depending particularly on the irregularity of the ground and the tighness of curves.In the case of tight curves,a spacing of 25 ft is often appropriate.StrippingThe upper layer of material encountered in an excavation is often topsoil(organic material),resulting from decomposition of vegetative matter.Such organic material is commonly referred to as stripping.This material is unsuitable for use in an embankment,and usually it must be handled in a separate excavation operation.It can be collected and disposed of off the project,or stockpiled for later use on the project to plate slopes.If the embankments are of limited height,the organic material below the footprint of the fill sections must be stripped before embankment placement can commence(see Fig.4.9).In the case of embankments over 5 ft in height,most specifications allow the organic material to remain if its thickness is only a few inches.When calculating the volume of cut sections,this stripping quantity must be subtracted from the net volume,as it cannot be used for embankment construction(Fig.4.10).In the case of fill sections,the quantity must be added to the calculated fill volume(Fig.4.10).剥离上层的材料中往往遇到表层（有机材料）的挖掘，从营养的有机物质分解产生材料.这通常被称为剥离。这种材料是不适用的，而且通常必须在一个单独的挖掘作业中进行处理。它收集和处理过的项目，以后或许可以在项目中使用斜坡板储存。如果堤防高度有限，下面的部分足迹的填充有机材料必须在破除之前开始填筑。在堤防高度超过5英尺的情况下，规范允许的有机物质其厚度必须保证有几英寸。在计算量减少的部分，溶出量必须减去净体积，因为它不能应用于路基施工中。在部分填充的情况下，必须增加填充的体积计算。Net VolumeThe computed volumes from the cross sections represent two different material states.The volumes from the fill cross sections represent compacted volume.If the volume is expressed in cubic yards,the notation is compacted cubic yards.In the case of cut sections,the volume is a natural in situ volume.The term bank volume is used to denote this in situ volume;if the volume is expressed in cubic yards the notation is bank cubic yards.If the cut and fill volumes are to be combined,they must be converted into compatible volumes.In Table 4.1 the conversion from compacted to bank cubic yards is made by dividing the compacted volume by 0.90.This value should be determined by soil testing of the actual material that will be hangdled.Earthwork Volume SheetAn eatthwork volume sheet,which can easily be constructed using a spreadsheet program,allows for the systematic recording of information and making the necessary earthwork calculations (see Table 4.1). Stations.Column 1 is a listing of all stations at which cross-sectional areas have been recorded. Area of cut.Column 2 is the cross-sectional area of the cut at each station. Usually this area must be computed from the project cross sections. Area of fill.Column 3 is the cross-sectional area of the fill at each station.Usually this area must be computed from the project cross sections.Note there can be both cut and fill at a station (see row 5,Table 4.1). Volume of cut.Column 4 is the volume of cut between the adjacent preceding station and the station.The average-end-area formula,Eq.4.4,is usually used to calculate this volume.This is a bank volume(bcy). Volume of fill.Column 5 is the volume of fill between the adjacent preceding station and the station.The average-end-area formula,Eq.4.4,is usually used to calculate this volume.This is a compacted volume(ccy). Stripping volume in the cut.Column 6 is the stripping volume of topsoil over the cut between the adjacent preceding station and the station.This volume is commonly calculated by multiplying the distance between stations or fractions of stations by the width of the cut.This provides the area of the cut footprint.The footprint area is then multiplied by an average depth of topsoil to derive the stripping volume.This represents a bank volume of cut material.Usually topsoil material is not suitable for use in the embankment.The average depth of topsoil must be determined by field investigation. Stripping volume in the fill.Column 7 is the stripping volume of topsoil under the fill between the adjacent preceding station and the station.This volume is commonly calculated by multiplying the distance between station or fractions of stations by the width of the fill.This provides the area of the fill footprint.To derive the stripping volume,the area of the embankment footprint is multiplied by an average depth of topsoil.The stripping is a bank volume,but it also represents an additional requirement for fill material,ccy of fill. Total volume of cut.Colume 8 is the volume of cut material available for use in embankment construction.It is derived by subtracting the cut stripping (col.6)from the cut volume(col.4)(see Fig.4.10).Total volume of fill.Column 9 is the total volume of fill required.It is derived by adding the fill stripping (col.7) to the fill volume(col.5)(see Fig.4.10).Adjusted fill.Column 10 is the total fill volume converted from compacted volume to bank volume.Algebraic sum.Column 11 is the difference between colunm 10 and column 8.This indicates the volume of material that is available(cut is positive) or required (fill is negative) within station increments after intrastation balancing.Mass ordinate.Column 12 is the running total of column 11 valuws from some point of beginning on the project profile.When the stations being summed are excavation sections,the value of this column will increase,while summing fill sections will result in a decrease of the column 12 values.Note that any material that could be used within a station length is not accounted for in the mass ordinate and therefore it is not accounted for in the mass diagram.The mass diagram accounts for only material that must be transported beyond the limits of the two cross sections that define the volume of material.Where there is both cut and fill between a set of stations,only the excess of one over the other is used in computing the mass ordinate.Cut material between two successive stations is first used to satisfy fill requirements between those same two successive stations before there is a contribution to the mass ordinate value.Likewise if there is a greater fill requirement between two successive stations than there is cut available,the cut contribution is accounted for first.Only after all of the cut material is used will there be a fill contribution to the mass ordinate value.The material used between two successive stations is considered to move at right angles to the centerline of the project and therefore is often termed crosshaul.The remaining material in either case represents a longitudinal haul along the length of the project(Fig.4.11).