某水庫(kù)除險(xiǎn)加固工程的穩(wěn)定分析及計(jì)算案例1.1壩坡抗滑穩(wěn)定計(jì)算工況加僻水庫(kù)設(shè)計(jì)正常蓄水位18m，設(shè)計(jì)洪水位為18.37m，校核洪水位為18.53m，死水位為16.41m。根據(jù)《碾壓式土石壩設(shè)計(jì)規(guī)范》的規(guī)定，土壩壩坡穩(wěn)定性的計(jì)算應(yīng)考慮水庫(kù)運(yùn)行過(guò)程中各種不利的工作條件。結(jié)合加僻水庫(kù)的具體情況，確定水庫(kù)大壩壩坡穩(wěn)定計(jì)算的工況為：1、水庫(kù)正常蓄水位18m與下游相應(yīng)的水位時(shí)下游壩坡穩(wěn)定最不利的情況；2、水庫(kù)設(shè)計(jì)洪水位18.37m與下游相應(yīng)的水位時(shí)下游壩坡穩(wěn)定最不利的情況；3、水庫(kù)校核洪水位18.53m與下游相應(yīng)的水位時(shí)下游壩坡穩(wěn)定最不利的情況；1.2計(jì)算斷面過(guò)對(duì)大壩壩體地基的地質(zhì)情況分析與勘測(cè)我們?cè)趬误w最高處做剖面，以此剖面為代表對(duì)對(duì)大壩進(jìn)行滲流分析。根據(jù)曾經(jīng)專(zhuān)家給出的的安全調(diào)查與評(píng)價(jià)的結(jié)果，大壩邊坡入滲線的脫險(xiǎn)點(diǎn)較高。在這次的加僻水庫(kù)除險(xiǎn)加固設(shè)計(jì)中我們計(jì)劃把壩頂?shù)膶挾扔稍瓉?lái)的四米增加一米也就是拓寬為5.0m，并且增加壩坡的坡比以達(dá)到增加壩體厚度的目的并下游設(shè)置棱體排水，降低浸潤(rùn)線。在壩體滲流計(jì)算中土層主要為填土，壩基為不透水壩基。加僻水庫(kù)的壩體穩(wěn)定性計(jì)算的土層劃分示意圖1所示。1.2.1計(jì)算參數(shù)根據(jù)已知資料我們可以查詢出各層巖土的物理力學(xué)參數(shù)，如下表。巖土名稱及編號(hào)天然密度ρo(g/cm3)飽和密度ρsat(g/cm3)凝聚力c(kPa)內(nèi)摩擦角φ(°)承載力特征值fak(kPa)備注填土①層1.91.951621120試驗(yàn)值粉質(zhì)粘土②-11.61.6310470經(jīng)驗(yàn)值細(xì)砂②-21.81.82032140經(jīng)驗(yàn)值1.2.2瑞典圓弧法應(yīng)用簡(jiǎn)單實(shí)用的條分法——瑞典圓弧法，假定滑裂面是一個(gè)圓柱面（在剖面上是一個(gè)圓弧），安全系數(shù)定義為土條在滑裂面上所提供的抗滑力矩和滑動(dòng)力矩之比，為了再進(jìn)一步簡(jiǎn)化計(jì)算，將可能滑動(dòng)面以上的土體劃分為若干鉛直土條，不考慮土條間相互作用的切應(yīng)力和正應(yīng)力等的影響，可以計(jì)算出作用于土條底面的法向力和切向力。將安全系數(shù)直接等于各個(gè)土條底部中點(diǎn)所受抗滑力之和與滑動(dòng)力的比值。穩(wěn)定安全系數(shù)計(jì)算公式為：在計(jì)算抗滑力矩時(shí)浸潤(rùn)線以上以天然容重計(jì)，對(duì)浸潤(rùn)線以下、下游水位以上的部分取浮容重；在計(jì)算滑動(dòng)力矩時(shí)，浸潤(rùn)線以上以天然容重計(jì)，浸潤(rùn)線以下、下游水位以上的部分取為飽和容重、下游水位以下的以浮容重計(jì)。1.3計(jì)算過(guò)程工況一土條號(hào)傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)834.0000.59379.35216.0000.3670.6005.8860.81036.38344.3731.4491444730.0000.52484.36416.0000.3671.0009.8100.85038.44542.182625.0000.43687.53416.0000.3671.40013.7340.87039.78636.993521.0000.36792.53616.0000.3671.60015.6960.91042.23933.162417.0000.29789.91616.0000.3671.80017.6580.93041.58426.289313.0000.22787.97416.0000.3671.80017.6580.95041.66519.79028.0000.14083.4216.0000.3671.90018.6390.96040.20211.61014.0000.07077.39116.0000.3671.90018.6390.97038.2155.39900.0000.00068.98416.0000.3671.70016.6770.97035.7910.000-1-4.000-0.07059.07816.0000.3671.70016.6770.97031.933-4.121-2-8.000-0.14047.33116.0000.3671.70016.6770.96027.206-6.587-3-13.000-0.22734.79316.0000.3671.60015.6960.95022.490-7.827-4-17.000-0.29725.40416.0000.3671.20011.7720.93020.003-7.427-5-21.000-0.3676.33716.0000.3670.9008.8290.91013.747-2.271土條號(hào)傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)758.0001.01215.59116.0000.3670.0000.0001.01019.33113.2221.3869316650.0000.87355.24416.0000.3670.0000.0001.23033.31142.319542.0000.733101.10916.0000.3670.0000.0001.42051.56367.655434.0000.593133.76716.0000.3670.2001.9621.59066.81274.802325.0000.436149.12216.0000.3670.9008.8291.73073.69663.022217.0000.297151.78316.0000.3671.40013.7341.83075.35044.37719.0000.157139.68316.0000.3671.50014.7151.89072.52321.85101.0000.017113.13916.0000.3671.40013.7341.92064.0211.975-17.0000.12274.32916.0000.3671.30012.7531.90049.4189.058-215.0000.26225.60116.0000.3670.7006.8671.85034.2166.626工況二傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)34.0000.59378.92616.0000.3670.9008.8290.81035.33244.1351.405489630.0000.52484.45816.0000.3671.40013.7340.85037.19642.22925.0000.43687.6616.0000.3671.70016.6770.87038.84737.04721.0000.36790.74316.0000.3672.00019.6200.91040.22632.51917.0000.29790.02516.0000.3672.10020.6010.93040.57326.32113.0000.22788.03516.0000.3672.30022.5630.95039.89919.8048.0000.14083.60416.0000.3672.30022.5630.96038.82611.6354.0000.07077.06916.0000.3672.20021.5820.97036.9965.3760.0000.00069.18616.0000.3672.20021.5820.97034.0420.000-4.000-0.07059.2716.0000.3672.20021.5820.97030.180-4.134-8.000-0.14047.48716.0000.3672.10020.6010.96025.819-6.609-13.000-0.22735.30916.0000.3672.00019.6200.95021.252-7.943-17.000-0.29719.70916.0000.3671.60015.6960.93016.512-5.762-21.000-0.3677.02416.0000.3671.30012.7530.91012.622-2.517傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)58.0001.01215.59116.0000.3670.0000.0001.01019.33113.2221.354726450.0000.87355.24416.0000.3670.0000.0001.23033.31142.31942.0000.733100.80116.0000.3670.0000.0001.42051.47567.44934.0000.593132.39816.0000.3670.5004.9051.59064.58074.03625.0000.436149.21816.0000.3671.30012.7531.73071.12463.06217.0000.297152.84516.0000.3671.70016.6771.83073.67344.6889.0000.157140.01816.0000.3671.80017.6581.89070.51521.9041.0000.017113.4116.0000.3671.80017.6581.92061.2331.9797.0000.12274.60316.0000.3671.70016.6771.90046.6619.09215.0000.26225.73816.0000.3671.0009.8101.85032.1776.661工況三土條號(hào)傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)834.0000.59379.43416.0000.3671.10010.7910.81034.88444.4191.3758418730.0000.52484.47416.0000.3671.50014.7150.85036.88142.237625.0000.43687.72816.0000.3671.90018.6390.87038.21637.075521.0000.36790.78916.0000.3672.10020.6010.91039.90032.536417.0000.29791.35816.0000.3672.30022.5630.93040.36226.710313.0000.22787.99416.0000.3672.40023.5440.95039.52619.79428.0000.14083.53316.0000.3672.50024.5250.96038.07611.62614.0000.07071.02216.0000.3672.40023.5440.97033.9504.95400.0000.00068.17216.0000.3672.30022.5630.97033.2870.000-1-4.000-0.07057.87816.0000.3672.30022.5630.97029.282-4.037-2-8.000-0.14047.96616.0000.3672.20021.5820.96025.640-6.676-3-13.000-0.22735.23416.0000.3672.00019.6200.95021.224-7.926-4-17.000-0.29721.52216.0000.3671.80017.6580.93016.477-6.292-5-21.000-0.3677.17616.0000.3671.40013.7340.91012.334-2.572土條號(hào)傾角alpha傾角alpha(弧度)土條重W(kN)粘聚力c(kPa)內(nèi)摩擦角(弧度)條塊孔隙水深h條塊孔隙水壓u條塊底長(zhǎng)度l抗滑力T滑動(dòng)力S安全系數(shù)758.0001.01215.59116.0000.3670.0000.0001.01019.33113.2221.3319643650.0000.87355.24416.0000.3670.0000.0001.23033.31142.319542.0000.733101.54616.0000.3670.0000.0001.42051.68867.947434.00