《鐵路工程測(cè)量》 課件 第27講（2） 地形圖的應(yīng)用

子項(xiàng)目6地形圖測(cè)繪地形圖測(cè)繪-----地形圖的應(yīng)用地形圖的應(yīng)用主要內(nèi)容場(chǎng)地平整土(石)方量的計(jì)算2場(chǎng)地平整土(石)方量計(jì)算的意義1重點(diǎn)：場(chǎng)地平整土(石)方量計(jì)算的意義和方法難點(diǎn)：場(chǎng)地平整土(石)方量的計(jì)算地形圖測(cè)繪-----地形圖的應(yīng)用比例尺1：10005250494851十、場(chǎng)地平整的土（石）方估算1、設(shè)計(jì)成水平場(chǎng)地的土石方量計(jì)算擬在圖上將原地面平整成某一高程的水平面，使填、挖土(石)方量基本平衡。右圖為1:1000比例尺地形圖，其步驟如下：比例尺1：10005250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D5方格的方向盡量與邊界方向、主要建筑物方向或施工坐標(biāo)方向一致。一般方格的邊長(zhǎng)以10m或20m為宜。圖中方格為20m×20m。各方格點(diǎn)的點(diǎn)號(hào)注于方格點(diǎn)的左下角，如圖中的A1A2…E3E4等。（１）繪制方格網(wǎng)ⅠⅡⅢⅣⅤ50.5比例尺1：10005250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.851.151.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.048.248.247.7（２）求各方格網(wǎng)點(diǎn)的地面高程利用求任意點(diǎn)的高程的方法在圖上求出各方格網(wǎng)點(diǎn)的地面高程Hi。并注記于方格網(wǎng)的右上角。ⅠⅡⅢⅣⅤ（３）計(jì)算設(shè)計(jì)高程用加權(quán)平均值法計(jì)算出場(chǎng)地原地形的平均高程，即為場(chǎng)地平整成水平面時(shí)填、挖方量保持平衡的設(shè)計(jì)高程。（當(dāng)場(chǎng)地較平坦時(shí)可用算術(shù)平均值）即：其中：H設(shè)——場(chǎng)地設(shè)計(jì)高程。Pi——方格網(wǎng)點(diǎn)的權(quán)。Hi——方格網(wǎng)點(diǎn)的地面高程。一般以各方格網(wǎng)點(diǎn)的高程影響土方量計(jì)算的方格的個(gè)數(shù)作為確定“權(quán)”的標(biāo)準(zhǔn)。如果該方格網(wǎng)點(diǎn)的高程只影響一個(gè)方格的土方量計(jì)算，則定權(quán)為1，影響2個(gè)則權(quán)為2，依此類推。如A1點(diǎn)的權(quán)為1；C1點(diǎn)處的權(quán)為2；D4點(diǎn)處的權(quán)為3；D2等點(diǎn)處的權(quán)均為4。即每個(gè)方格網(wǎng)點(diǎn)的權(quán)即為該點(diǎn)處四周方格的個(gè)數(shù)。52504951

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.850.551.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.248.247.750.050.050.050.050.050.050.050.050.050.050.050.050.050.050.0H設(shè)=[1×（52.0+50.5+48.0+47.7+48.0）+2×(52.3+51.8+51.1+49.7+48.8+48.2+48.2+49.2+50.0+51.1)+3×48.5+4×(51.5+51.1+50.3+50.5+50.2+49.3+49.4+49.2)]÷(1×5+2×10+3×1+4×8)=50.0m51.148.050.050.050.050.050.050.050.050.050.0ⅠⅡⅢⅣⅤ485250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.851.150.551.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.048.248.247.750.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.0+2.0+2.3+1.8+1.1+0.5+1.1+1.5+1.1+0.3-0.3+0.0+0.5+0.2-0.7-1.2-2.0-1.5-0.8-0.6-0.8-2.0-1.8-1.8-2.3（４）計(jì)算方格網(wǎng)點(diǎn)填、挖值hi（量）各方格網(wǎng)點(diǎn)地面高程與設(shè)計(jì)高程之差，即為該點(diǎn)填、挖數(shù)值：將計(jì)算出的填挖量注于相應(yīng)方格網(wǎng)點(diǎn)的左上角，如方格Ⅰ中的52.0-50.0＝+2.0等。h為“+”表示挖深，為“-”表示填高。hi=H地-H設(shè)ⅠⅡⅢⅣⅤ（５）確定填挖邊界線在地形圖上根據(jù)等高線，用目估法或比例內(nèi)插法確定出高程為設(shè)計(jì)高程的高程點(diǎn)，即填挖邊界點(diǎn)，也叫零點(diǎn)。零點(diǎn)位置的確定有目估法和比例內(nèi)插法兩種。填挖邊界點(diǎn)：填挖邊界線：連接相鄰零點(diǎn)的曲線(圖中50米的等高線)即為填挖邊界線。高于填挖邊界線高程的區(qū)域?yàn)橥诜絽^(qū)域，反之為填方區(qū)域。5250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.851.150.551.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.048.248.247.750.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.0+2.0+2.3+1.8+1.1+0.5+1.1+1.5+1.1+0.3-0.3+0.0+0.5+0.2-0.7-1.2-2.0-1.5-0.8-0.6-0.8-2.0-1.8-1.8-2.3ⅠⅡⅢⅣⅤab（６）計(jì)算填、挖土（石）方量計(jì)算填、挖土(石)方量有三種情況：現(xiàn)以方格B2C2C3B3、C2D2D3C3、D2E2E3D3為例，說(shuō)明計(jì)算方法：①方格B2C2C3B3全為挖方，則三是既有挖方，又有填方的方格，如方格C2D2D3C3。二是整個(gè)方格為填方，如D2E2E3D3；一是整個(gè)方格為挖方，如圖中方格B2C2C3B3；5250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.851.150.551.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.048.248.247.750.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.0+2.0+2.3+1.8+1.1+0.5+1.1+1.5+1.1+0.3-0.3+0.0+0.5+0.2-0.7-1.2-2.0-1.5-0.8-0.6-0.8-2.0-1.8-1.8-2.3ab其中A填應(yīng)按曲邊梯形（或近似梯形）的面積計(jì)算。即：代入得②方格C2D2D3C3既有挖方、又有填方，則③方格D2E2E3D3全為填方，則5250494851

E1E2E3E4A1A2A3A4A5B1B2B3B4B5C1C2C3C4C5D1D2D3D4D552.052.351.851.150.551.151.551.150.349.750.050.550.249.348.849.249.449.248.548.048.048.248.247.750.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.050.0+2.0+2.3+1.8+1.1+0.5+1.1+1.5+1.1+0.3-0.3+0.0+0.5+0.2-0.7-1.2-2.0-1.5-0.8-0.6-0.8-2.0-1.8-1.8-2.3ab根據(jù)各方格的填、挖土（石）方量，可求得整個(gè)場(chǎng)地的總填、挖土（石）方