地下工程课程设计

《地下工程》课程设计——新奥法隧道二次衬砌结构设计姓名：班级：学号：指导老师：华中科技大学土木工程与力学学院2015年12月2目录1、设计任务书.......................................................32.1基本设计资料................................................32.2设计要求....................................................42.3参考资料....................................................42、计算工况.........................................................52.1参数.........................................................52.2围岩压力.....................................................52.3拟定二次衬砌截面尺寸.........................................53、衬砌结构内力.....................................................64、衬砌结构配筋....................................................1231、设计任务书1.1基本设计资料（1）工程概况某三心圆带仰拱隧道，隧道内净空的高度为8.8m，内净空宽度为11m，建筑限界和内净空的横断面形状和尺寸如图2-1所示，地表至隧道内净空顶部H=20~60m。拟采用新奥法复合式支护结构，二次衬砌采用C25钢筋混凝土，混凝土弹性模量Ec=29.5GPa，泊松比μc=0.2，钢筋采用HRB335，钢筋抗拉强度标准值为340MPa。（2）围岩性质假设隧道所在土体为黏性土，围岩级别为Ⅴ级，平均γ=18~20kN/m3，平均黏聚力c=30~60kPa，内摩擦角φ=20~30°，泊松比为0.33~0.37，变形模量E为15~30MPa。图1-10衬砌横断面尺寸（单位：cm）41.2设计要求（1）确定具体计算工况，包括选定隧道埋深、土体黏聚力、内摩擦角、变形模量等指标。（各位同学之间不得雷同）。（2）根据经验，初步拟定二次衬砌截面尺寸。（3）确定隧道埋深条件（深埋或浅埋），并计算围岩压力。深埋隧道采用普氏理论进行计算，浅埋隧道采用岩柱理论或太沙基松动理论进行计算，超浅埋隧道采用土柱理论进行计算。（4）采用荷载-结构模型(假定抗力计算模型或弹性地基梁计算模式)计算二次衬砌内力，计算中只考虑围岩压力和二次衬砌结构自重，直接按照标准值进行组合，无需考虑荷载组合分项系数。（5）验算截面承载力，优化截面尺寸，并进行配筋设计。验算中，只需进行正截面抗拉、抗压、抗弯验算，无需进行正截面和斜截面抗剪验算、裂缝验算、变形验算等。（6）编写设计计算书。1.3参考资料（1）公路隧道设计规范(JTGD70-2004)；（2）《公路隧道设计细则》JTGTD70—2010。52、计算工况2.1参数围岩性质：围岩级别V级，平均重度γ=18kN/m3，平均粘聚力c=50kPa，内摩擦角ϕ=20°，泊松比μ=0.35，变形模量E=25Mpa，地表至隧道内净空顶部H=50m。宽度影响系数：𝑤=1+𝑖×(𝐵−5)=1+0.1×(11−5)=1.6坍落拱高度：ℎ𝑞=0.45×2𝑠−1𝑤=0.45×25−1×1.6=11.52𝑚H𝑝=2.5ℎ𝑞=2.5×11.52𝑚=28.8𝑚𝐻=50𝑚𝐻𝑝=28.8𝑚故隧道为深埋，采用普氏理论计算围岩压力。2.2围岩压力洞顶竖向压力：𝑞=𝛾ℎ𝑞=18𝑘𝑁/𝑚3×11.52𝑚=207.36𝑘𝑁/𝑚2侧向压力：𝑒1=𝑞𝑡𝑎𝑛2(45°−𝜙2)=207.36𝑘𝑁/𝑚2×𝑡𝑎𝑛2(45°−20°2)=101.67𝑘𝑁/𝑚2𝑒2=(𝑞+𝛾𝐻′)𝑡𝑎𝑛2(45°−𝜙2)=(207.36𝑘𝑁/𝑚2+18𝑘𝑁/𝑚3×(5.5𝑚+2.034𝑚))×𝑡𝑎𝑛2(45°−20°2)=168.16𝑘𝑁/𝑚22.3拟定二次衬砌截面尺寸参考《公路隧道设计细则》JTGTD70—2010的表13.2.3整体式衬砌设计参数，初步拟定二次衬砌截面厚度为50cm。二次衬砌采用C25钢筋混凝土，弹性模量Ec=29.5Gpa，泊松比μc=0.2，钢筋采用HRB335，钢筋抗拉强度标准值为340MPa。63、衬砌结构内力利用ANSYS软件，采用弹性地基梁模型计算衬砌结构的内力，计算流程如图3.1所示。确定模型单元剖分将荷载换算为等效节点力用ANSYS建立模型（带仰拱）计算并判断是否取消弹簧输出计算结果结束拟定衬砌截面尺寸判断埋深选取合适方法计算荷载是否确定计算工况，选定相关参数图3.1衬砌结构内力计算流程图编程命令流：!(1)创建物理环境fini/clear/TITLE,TunnelSupportStructuralAnalysis!进入前处理器/PREP7!定义单元ET,1,BEAM3!定义梁单元ET,2,COMBIN14!定义弹簧单元!定义材料属性MP,EX,1,2.95E10!混凝土衬砌弹性模量MP,PRXY,1,0.2!凝土衬砌泊松比MP,DENS,1,2500!混凝土衬砌密度!定义实常数R,1,0.50,0.50*0.50*0.50/12,0.50,!衬砌面积,惯性矩,厚度!(2)建立几何模型!创建隧道衬砌支护关键点!定义曲率中心点7K,1,0,11.7,!L1曲率中心K,2,4.1824,-1.6607,!L2曲率中心K,3,0,0,!L3/L4曲率中心K,4,-4.1824,-1.6607,!L5曲率中心K,5,-4.4811,-2.615,!由节点坐标生成关键点K,6,4.4811,-2.615,K,7,5.1118,-2.0297,K,8,0,5.5,K,9,-5.1118,-2.0297,!创建隧道衬砌支护线LARC,5,6,1,15!由2个端点及曲率中心加半径生成弧线LARC,6,7,2,1LARC,7,8,3,5.5LARC,8,9,3,5.5LARC,9,5,4,1!(3)划分网格，生成隧道衬砌支护单元lsel,s,line,,1,5,1!选择线L1-L5LATT,1,1,1!给所选的线赋予材料特性lsel,s,line,,1LESIZE,all,,,8!设置网格划分份数为4lsel,s,line,,2,5,3LESIZE,all,,,1lsel,s,line,,3,4,1LESIZE,all,,,10,lsel,allLmesh,all!线网格划分，生成支护单元!(4)添加弹簧单元/PNUM,NODE,1!打开节点号开关!生成30根弹簧单元!弹簧节点号，弹簧刚度，弹簧相对位置psprng,1,tran,101355000,-0.2987,-0.9544psprng,3,tran,113760000,-0.2255,-0.9742psprng,4,tran,113760000,-0.1511,-0.9885psprng,5,tran,113760000,-0.0757,-0.9971psprng,6,tran,113760000,0.0000,-1.0000psprng,7,tran,113760000,0.0757,-0.9971psprng,8,tran,113760000,0.1511,-0.9885psprng,9,tran,113760000,0.2255,-0.9742psprng,2,tran,98075000,0.2987,-0.9544psprng,10,tran,107200000,0.9309,-0.3652psprng,12,tran,107200000,0.9840,-0.17828psprng,13,tran,107200000,0.9999,0.0155psprng,14,tran,107200000,0.9780,0.2087psprng,15,tran,107200000,0.9192,0.3938psprng,16,tran,107200000,0.8256,0.5643psprng,17,tran,107200000,0.7009,0.7133psprng,18,tran,107200000,0.5497,0.8354psprng,19,tran,107200000,0.3777,0.9260psprng,20,tran,107200000,0.1914,0.9815psprng,11,tran,107200000,0.0000,1.0000psprng,22,tran,107200000,-0.1954,0.9807psprng,23,tran,107200000,-0.3815,0.9244psprng,24,tran,107200000,-0.5531,0.8332psprng,25,tran,107200000,-0.7038,0.7104psprng,26,tran,107200000,-0.8279,0.5608psprng,27,tran,107200000,-0.9208,0.3900psprng,28,tran,107200000,-0.9788,0.2046psprng,29,tran,107200000,-1.0000,0.0113psprng,30,tran,107200000,-0.9832,-0.1823psprng,21,tran,98075000,-0.9294,-0.3691!(5)保存模型allsSAVEFINISH!(6)施加约束和荷载/SOL!施加约束NSEL,S,NODE,,31,60,1!选择隧道支护线上所有节点d,all,uy,0!对所选择节点约束X方向位移d,all,ux,0!对所选择节点约束Y方向位移!施加重力加速度allselACEL,acely,0,9.8,0,!施加围岩压力allself,11,fx,0$f,11,fy,-2.209E+05f,20,fx,-2.136E+04$f,20,fy,-2.167E+05f,19,fx,-4.299E+04$f,19,fy,-2.044E+05f,18,fx,-6.500E+04$f,18,fy,-1.842E+05f,17,fx,-8.717E+04$f,17,fy,-1.571E+05f,16,fx,-1.089E+05$f,16,fy,-1.240E+059f,15,fx,-1.291E+05$f,15,fy,-8.625E+04f,14,fx,-1.465E+05$f,14,fy,-4.522E+04f,13,fx,-1.595E+05$f,13,fy,-1.204E+04f,22,fx,2.136E+04$f,22,fy,-2.167E+05f,23,fx,4.299E+04$f,23,fy,-2.044E+05f,24,fx,6.500E+04$f,24,fy,-1.842E+05f,25,fx,8.717E+04$f,25,fy,-1.571E+05f,26,fx,1.089E+05$f,26,fy,-1.240E+05f,27,fx,1.291E+05$f,27,fy,-8.625E+04f,28,fx,1.465E+05$f,28,fy,-4.422E+04f,29,fx,1.595E+05$f,29,fy,-1.204E+04f,12,fx,-1.665E+05f,10,fx,-8.414E+04f,30,fx,1.665E+05f,21,fx,8.414E+04!(7)求解分析修改模型!进入求解器all