围岩压力计算方法课件
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1围岩压力计算1围岩压力计算深埋和浅埋情况下围岩压力的计算方式不同,深埋和浅埋的分界按荷载等效高度值,并结合地质条件、施工方法等因素综合判断。
按等效荷载高度计算公式如下:HP =(2~2.5)qh式中: Hp——隧道深浅埋的分界高度;hq ——等效荷载高度,qh=qγ;q——垂直均布压力(kN/m2);γ——围岩垂直重度(kN/m3)。
二次衬砌承受围岩压力的百分比按下表取值:表4.1 复合式衬砌初期支护与二次衬砌的支护承载比例围岩级别初期支护承载比例二次衬砌承载比例双车道隧道三车道隧道双车道隧道三车道隧道ⅠⅡ100 100 安全储备安全储备Ⅲ100 ≥80 安全储备≥20 Ⅳ≥70 ≥60 ≥30 ≥40 Ⅴ≥50 ≥40 ≥50 ≥60 Ⅵ≥30 ≥30 ≥80 ≥85浅埋地段≥50 ≥30~50≥60 ≥60~801.1 浅埋隧道围岩压力的计算方法隧道的埋深H 大于hq 而小于Hp 时,垂直压力Q B B t tq H==γH(1-λθ)浅浅tan 。
表4.3 各级围岩的θ值及0φ值围岩级别Ⅲ ⅣⅤθ0.90φ (0.7~0.9)0φ (0.5~0.7)0φ 0φ60°~70°50°~60°40°~50°2(tan 1)tan tan tan c cc ϕ+ϕβϕ+ϕ-θc tan =tan 侧压力系数()tan tan tan tan tan tan tan tan cc c β-ϕλ=β1+βϕ-θ+ϕθ⎡⎤⎣⎦作用在支护结构两侧的水平侧压力为:e 1=γh λ ; e 2=γ(h+Ht)λ 侧压力视为均布压力时:Ⅴ级围岩的等效荷载高度hq=0.45×24×[1+0.1×(10-5)]=10.8m Hp=2.5hq=27m,H<Hq,故为浅埋。
取φ0=45°,θ=0.6φ0=27°,h=20m ,tan β=3.02,λ=0.224,tan θ=0.51, 计算简图:()212+1e =e e垂直压力q=19×20(1-0.224×20×0.51/10)=293.18KN/mPg=πdγ=π×0.4×25=31.4KN/m地基反力P=324.58KN/me1=γhλ=19×20×0.224=85.12e2=γ(h+Ht)λ=19×(20+8.17)×0.224=119.89水平均布松动压力e=(e1+e2)/2=102.51KN/mⅤ级围岩二衬按承受50%围岩压力进行计算,则垂直压力为q×50%=146.59KN/m地基反力为P×50%=162.29KN/m水平压力为e×50%=51.255KN/m2衬砌结构内力计算表4.7 等效节点荷载节点号X Y Fx FY1 2072.742591 1544.439864 31304.66167 2146.3194733 2072.757146 1543.972843 26425.97397 4953.6865524 2072.800753 1543.507634 26256.11233 9886.1615315 2072.873244 1543.046044 25973.81825 14776.30132 2 2072.974338 1542.589864 24195.36508 23664.97654 7 2073.219875 1542.146273 20103.90754 40260.144586 2073.651412 1541.88012 14076.90744 57497.450139 2074.154041 1541.73685 8935.043764 69728.9710410 2074.661668 1541.61244 6853.524396 83279.0729311 2075.173585 1541.507065 5880.169138 84021.8174612 2075.689079 1541.42087 4898.834757 84650.5451413 2076.20743 1541.353977 3910.852859 85164.4039714 2076.727917 1541.306479 2917.564275 85562.6960915 2077.249814 1541.27844 1920.316498 85844.8859416 2077.772394 1541.269902 920.4626612 86010.5840317 2078.294929 1541.280875 80.64000409 86059.5712718 2078.81669 1541.311344 -1081.63324 85991.7746219 2079.33695 1541.361267 -2081.158789 85807.2914620 2079.854984 1541.430575 -3077.860187 85506.3814621 2080.37007 1541.51917 -4070.385072 85089.4259922 2080.88149 1541.626929 -5057.386718 84557.009323 2081.388532 1541.753702 -6037.525576 83909.86178 2081.890488 1541.899313 -7009.471578 83148.84332 25 2082.285648 1542.168245 -9244.515303 74199.42618 24 2082.510844 1542.589864 -14047.47015 52646.5891327 2082.611937 1543.046044 -19236.06506 36865.6479128 2082.684429 1543.507634 -23588.83673 22476.6373729 2082.728036 1543.972843 -25973.81825 14776.30132 26 2082.742591 1544.439864 -26256.11233 9886.16153130 2082.706135 1545.042547 -26425.97397 4953.68655231 2082.5973 1545.636442 -31304.66167 2146.31214432 2082.417672 1546.212888 -35817.57933 -13486.3166533 2082.169871 1546.76348 -34895.66231 -26741.8859834 2081.85751 1547.280188 -33376.67067 -39539.8892835 2081.485145 1547.755477 -31286.59479 -51661.3504136 2081.058204 1548.182418 -28661.19683 -62898.8811837 2080.582915 1548.554783 -25545.39795 -73060.1921438 2080.066207 1548.867144 -21992.50975 -81971.412939 2079.515615 1549.114945 -18063.32375 -89480.0825240 2078.939169 1549.294573 -13825.06958 -95457.7295441 2078.345274 1549.403408 -9350.264619 -99802.0707842 2077.742591 1549.439864 -4715.473839 -102438.770543 2077.139908 1549.403408 0 -103322.708244 2076.546013 1549.294573 4715.473839 -102438.763145 2075.969566 1549.114945 9350.264619 -99802.0707846 2075.418975 1548.867144 13825.06984 -95457.7368747 2074.902267 1548.554783 18063.324 -89480.0898548 2074.426978 1548.182418 21992.50975 -81971.412949 2074.000037 1547.755477 25545.39769 -73060.1848150 2073.627672 1547.280188 28661.19683 -62898.8811851 2073.315311 1546.76348 31286.59505 -51661.3504152 2073.06751 1546.212888 33376.67067 -39539.8819553 2072.887882 1545.636442 34895.66205 -26741.8859854 2072.779047 1545.042547 35817.57908 -13486.32398表4.8 轴力、剪力、弯矩详细数据节点号轴力弯矩剪力1 -8.92E+05 -13456 -109952 -8.83E+05 -8352.6 -638913 -8.73E+05 21398 -1.19E+054 -8.61E+05 76686 -1.72E+055 -8.69E+05 1.57E+05 -252076 -7.80E+05 1.69E+05 3.16E+057 -2.08E+06 7906.2 339838 -2.06E+06 -11168 325749 -2.05E+06 -29519 2963810 -2.04E+06 -46347 2539511 -2.03E+06 -60967 2007312 -2.02E+06 -72813 1390913 -2.02E+06 -81442 7144.714 -2.02E+06 -86540 26.68815 -2.02E+06 -87920 -7193.616 -2.02E+06 -85526 -1426717 -2.02E+06 -79433 -2094718 -2.03E+06 -69844 -2698819 -2.04E+06 -57093 -3214820 -2.05E+06 -41637 -3619121 -2.07E+06 -24058 -3889122 -2.08E+06 -5056.4 -4002923 -7.88E+05 14553 -3.07E+0524 -8.72E+05 1.60E+05 1869325 -8.67E+05 1.51E+05 1.61E+0526 -8.78E+05 75321 1.12E+0527 -8.89E+05 22802 6085928 -8.97E+05 -5736 1042929 -9.06E+05 -10643 -1582730 -9.04E+05 -976.56 -1884631 -8.96E+05 10731 -2262932 -8.82E+05 24936 -2597333 -8.61E+05 41366 -2494434 -8.33E+05 57370 -1258435 -7.99E+05 66092 2076436 -7.60E+05 54844 4538037 -7.22E+05 28879 5781438 -6.87E+05 -4468.5 5896639 -6.58E+05 -38409 5047240 -6.38E+05 -67143 3459441 -6.27E+05 -86237 1407042 -6.26E+05 -92913 -8065.143 -6.37E+05 -86224 -2867644 -6.57E+05 -67117 -4472845 -6.85E+05 -38371 -5348046 -7.19E+05 -4418.2 -5266647 -7.57E+05 28940 -4064448 -7.94E+05 54916 -1651049 -8.29E+05 66173 1653250 -8.56E+05 57316 2859051 -8.76E+05 40997 2930652 -8.90E+05 24050 2556953 -8.98E+05 9154.2 2115954 -8.99E+05 -3292.6 17015内力图分析(1)轴力:由ANSYS建模分析围岩衬砌内力得出轴力图如图,最大轴力出现在仰拱段,其值为626.383kN。