计，然后根据结构计算进行验算，再作出适当调整。
复合衬砌是由初期支护和二次衬砌及中间加防水层组合而成的衬砌形式，复合衬砌设计应符合下列规定：
1) 初期支护宜采用喷锚支护，即由喷射混凝土、锚杆、钢筋网和钢架等支护形
式单独或组合使用，锚杆支护宜采用全长粘结锚杆。
2) 二次衬砌宜采用模筑混凝土或模筑钢筋混凝土结构，衬砌截面宜采用连接圆
顺的等厚衬砌断面，仰拱厚度宜与拱墙厚度相同。
3) 在确定开挖断面时，除应满足隧道净空和结构尺寸外，还应考虑初期支护并
预留适当的变形量，预留变形量的大小可根据围岩级别、断面大小、埋置深度、施工方法、和支护情况等，采用工程类比法预测。
具体参看衬砌方案图
围初期支护（喷射混凝土） 岩级厚度强度 部位 位置 别 （cm） Ⅴ C20 拱部、边墙 20 拱、墙 锚杆 间距长度（m） （m） 1.0 3.5 二次衬砌（钢筋混凝土） 部位 拱、墙、仰拱 厚度（cm) 60 钢筋网 刚架 拱、墙（双层） 拱、墙、@20×20 仰拱
2.2.4计算衬砌结构的内力
衬砌结构的内力计算按照荷载结构法进行计算，运用结构力学求解器（工程版）Vs2.0。深埋围岩的弹性抗力系数K=100Gpa，衬砌材料采用C40混凝土，弹性模量分别为33.5Gpa，容重分别为25 KN·m-3。
衬砌结构上的荷载图如下图：
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竖向围岩土压力弹性抗力水平压力地层反力
图2-1衬砌结构荷载图
荷载只考虑三种荷载：①围岩压力；②衬砌自重；③弹性抗力 衬砌结构的结构力学建模简图如下图：
( 28 )29( 27 )2827( 26 )26( 25 )25( 24 )24( 23 )23( 22 )22( 21 )21( 20 )20( 19 )19( 18 )( 29 )30( 30 )1( 1 )2( 2 )3( 3 )4( 4 )5( 5 )6( 6 )7( 7 )8( 8 )9( 9 )10( 10 )( 11 )11( 12 )1218( 17 )17( 16 )16( 15 )15( 14 )14( 13 )13
图2-2衬砌结构建模简图
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内力计算：
杆端内力值 ( 乘子 = 1)
杆端 1 杆端 2
----------------------------- ----------------------------
单元码 轴力 剪力 弯矩 轴力 剪力 弯矩
1 -1852.91532 161.091659 644.263799 -1879.94443 -267.179726 565.014878 2 -1903.46465 48.6917698 565.014878 -1980.80174 -361.168943 331.377845 3 -2032.82632 -42.7677187 331.377845 -2150.79333 -416.861876 -11.9415411 4 -2198.60501 -157.530807 -11.9415411 -2347.46378 -525.192670 -561.584506 5 -2421.46599 18.9159488 -561.584506 -2571.91589 -251.976105 -734.920990 6 -2599.93103 101.463674 -734.920990 -2714.88545 -83.4558220 -724.107679 7 -2681.53961 475.787823 -724.107679 -2777.12983 298.189787 -49.6307087 8 -2759.68391 230.548994 -49.6307087 -2788.51319 99.1620686 197.625001 9 -2793.08602 -95.1430225 197.625001 -2803.60165 -228.084579 -54.4694243 10 -2774.34774 -460.865830 -54.4694243 -2808.94563 -562.872753 -733.350147 11 -2685.31226 635.142444 -733.350147 -2735.32815 614.936926 316.249500 12 -2860.06632 53.4855438 316.249500 -2894.63170 42.4756396 383.122001 13 -2941.18495 -71.6458093 383.122001 -2966.78175 -76.5958277 264.445334 14 -2986.16631 -115.466585 264.445334 -3001.74257 -117.386083 90.2443798 15 -3021.27186 -41.5055013 90.2443798 -3026.49887 -41.7187773 27.9824674 16 -3026.51302 41.3720198 27.9824674 -3021.28601 41.1587438 89.7255458 17 -3001.70552 112.369294 89.7255458 -2986.12927 110.449796 256.420214 18 -2967.08832 72.2004619 256.420214 -2941.49151 67.2504436 368.059352 19 -2895.50627 -44.4156880 368.059352 -2860.94090 -55.4255922 298.482926 20 -2736.81922 -613.444142 298.482926 -2686.80334 -633.649660 -748.609959 21 -2801.24790 578.431566 -748.609959 -2766.65001 476.424643 -49.0939325 22 -2794.19789 234.493409 -49.0939325 -2783.68226 101.551853 212.997352 23 -2778.56716 -98.2491238 212.997352 -2749.73787 -229.636050 -32.8890930 24 -2767.02084 -296.965015 -32.8890930 -2671.43062 -474.563050 -705.231426 25 -2705.52516 76.7849372 -705.231426 -2590.57074 -108.134559 -724.056169 26 -2563.59363 244.047937 -724.056169 -2413.14373 -26.8441165 -562.512698 27 -2341.21038 515.548454 -562.512698 -2192.35162 147.886591 -28.3983493 28 -2145.82295 406.497941 -28.3983493 -2027.85594 32.4037841 299.438397 29 -1983.68844 371.680612 299.438397 -1906.35135 -38.1801011 548.794435 30 -1880.92213 278.036627 548.794435 -1853.89303 -150.234758 644.263799
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位移计算：
杆端位移值 ( 乘子 = 1)
杆端 1 杆端 2
----------------------------- ------------------------------ 单元码 u -水平位移 v -竖直位移 θ-转角 u -水平位移 v -竖直位移 θ-转角
1 0.00026456 -0.02538379 -0.00009158 0.00027115 -0.02427451 0.00153862 2 0.00027115 -0.02427451 0.00153862 0.00105140 -0.02106787 0.00277676 3 0.00105140 -0.02106787 0.00277676 0.00296216 -0.01684286 0.00328783 4 0.00296216 -0.01684286 0.00328783 0.00556942 -0.01259767 0.00265384 5 0.00556942 -0.01259767 0.00265384 0.00756410 -0.01052652 0.00113756 6 0.00756410 -0.01052652 0.00113756 0.00792070 -0.01014179 -0.00027851 7 0.00792070 -0.01014179 -0.00027851 0.00626619 -0.01046341 -0.00132214 8 0.00626619 -0.01046341 -0.00132214 0.00437038 -0.01050571 -0.00109724 9 0.00437038 -0.01050571 -0.00109724 0.00293886 -0.01024656 -0.00086738 10 0.00293886 -0.01024656 -0.00086738 0.00151682 -0.00963397 -0.00170898 11 0.00151682 -0.00963397 -0.00170898 0.00024911 -0.00609102 -0.00228188 12 0.00024911 -0.00609102 -0.00228188 -0.00042268 -0.00354166 -0.00147068 13 -0.00042268 -0.00354166 -0.00147068 -0.00057609 -0.00191823 -0.00060919 14 -0.00057609 -0.00191823 -0.00060919 -0.00049251 -0.00137599 -0.00016855 15 -0.00049251 -0.00137599 -0.00016855 -0.00034689 -0.00124680 -0.00002181 16 -0.00034689 -0.00124680 -0.00002181 -0.00019859 -0.00131047 0.00012430 17 -0.00019859 -0.00131047 0.00012430 -0.00010623 -0.00178143 0.00055434 18 -0.00010623 -0.00178143 0.00055434 -0.00023876 -0.00329698 0.00138517 19 -0.00023876 -0.00329698 0.00138517 -0.00086654 -0.00570830 0.00215843 20 -0.00086654 -0.00570830 0.00215843 -0.00204169 -0.00902236 0.00153954 21 -0.00204169 -0.00902236 0.00153954 -0.00323946 -0.00955853 0.00068708 22 -0.00323946 -0.00955853 0.00068708 -0.00440816 -0.00979639 0.00094378 23 -0.00440816 -0.00979639 0.00094378 -0.00610418 -0.00977273 0.00120861 24 -0.00610418 -0.00977273 0.00120861 -0.00761088 -0.00949399 0.00021645 25 -0.00761088 -0.00949399 0.00021645 -0.00720915 -0.00991043 -0.00117000 26 -0.00720915 -0.00991043 -0.00117000 -0.00518846 -0.01200579 -0.00267402 27 -0.00518846 -0.01200579 -0.00267402 -0.00255609 -0.01628907 -0.00333123 28 -0.00255609 -0.01628907 -0.00333123 -0.00059978 -0.02060850 -0.00288011 29 -0.00059978 -0.02060850 -0.00288011 0.00023436 -0.02401194 -0.00170168 30 0.00023436 -0.02401194 -0.00170168 0.00026456 -0.02538379 -0.00009158
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内力计算图：
-562.51-562.51-560.53-724.06-724.06-705.23-686.11-705.23-28.40299.44299.44331.38331.38548.79551.44565.01548.79569.23565.01644.26644.26682.86689.35-11.94-561.58-561.58-560.79-734.92-734.92-701.75-724.11-724.11-32.89213.00213.00-49.09298.48298.48368.06368.06256.42256.42-748.61y-748.6189.7327.9890.24264.45264.45316.25383.12316.25383.12-49.63197.63197.63-54.47-733.35-733.35x
图2-3结构弯矩图（单位KN·m）
-1852.92-1853.89-1903.46-1906.35-1880.92-1879.94-2032.83-1980.80-1983.69-2027.86-2198.61-2150.79-2145.82-2192.35-2341.21-2413.14-2563.59-2590.57-2671.43-2705.53-2749.74-2767.02-2783.68-2778.57-2421.47-2347.46-2599.93-2571.92-2681.54-2714.89-2759.68-2777.13-2788.51-2793.09-2766.65-2686.80-2774.35-2803.60-2860.94-2735.33-2685.31-2794.20-2941.49-2894.63-2860.07-2736.82-2986.13-2808.95-2966.78-3021.29-3001.74-2941.18-3026.50-2895.51-2986.17-2801.25-2967.09-3021.27-3001.71-3026.51yx图2-4结构轴力图（单位KN）
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