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按下式近似计算:Ri'?(?i?1??i2)?Si外(6-31)

(3)抗力集中力与摩擦力的合力Ri

按下式计算:Ri?Ri'1??2,??0.2。(6-32) 则:Ri?1.0198Ri'

?其作用方向与抗力集中力Ri'的夹角??arctan??11.3099,由于摩擦阻力的方

向与衬砌位移的方向相反,其方向向上,Ri作用点即为Ri'与衬砌外缘的交点。将Ri的方向线延长,使之交于竖直轴,量取夹角?k,将Ri分解为水平与竖直两个分力:

?RH?Risin?i(6-33) ??RV?Ricos?i将计算结果列于表6.7。

表6.7弹性抗力及摩擦力计算表

截面 3 4 5 6 7 8 ?i 0 1 ?i?1??i2?Si外 0 Ri 0 0.446 1.273 1.564 1.192 0.454 ?i 0 61 73 85 98 110 sin?i 0 0.875 0.956 0.996 0.990 0.940 cos?i 1 0.485 0.292 0.087 -0.139 -0.342 RH RV 0 0.216 0.372 0.136 -0.166 -0.155 0 0 0.390 1.217 1.559 1.180 0.427 0.5388 0.2694 1.622 0.7694 1.622 0.8916 0.9458 1.622 0.5495 0.72055 1.622 0 0.27475 1.622 (4).计算单位抗力及其相应的摩擦力在基本结构中产生的内力弯矩: Mi0????Rjrji(6-34) 轴力:

Ni0??sin?i?RV?cos?i?RH(6-35) 计算结果如表6.8和表6.9。

0表6.8M?计算结果

截 面 R4?0.446?h r4i ?R4r4i R5?1.273?h r5i R6?1.564?h r6i R7?1.192?h R8?0.454?h r7i ?R5r5i ?R6r6i ?R7r7i r8i ?R8r8i 0 M?4 0.2324 -0.104 5 1.3202 -0.589 -0.104 -0.664 0.0594 -0.076

6 2.8746 -1.282 7 4.3452 -1.938 8 5.6382 -2.515 1.9477 -2.479 3.0469 -3.879 4.4881 -5.713 0.1402 -0.219 -3.981 -8.659 1.7012 -2.661 0.152 -0.181 3.2271 -5.047 1.6966 -2.022 0表6.9N?计算表

0.3273 -0.149 -15.446 截面 4 5 6 7 8 ? sin? cos? sin??RV0 RRcos??RH N? ?V?H 0.230 0.617 0.500 -0.335 0 -0.055 -0.074 0.214 0.891 0.403 53.948 0.808 0.589 0.216 0.39 0.175 67.435 0.923 0.384 0.588 1.607 0.543 80.922 0.987 0.158 0.724 3.166 0.715 94.409 0.997 -0.077 0.558 4.346 0.556 90 1 0 0.403 4.773 0.403 (5)单位抗力及相应摩擦力产生的载位移

表6.10单位抗力及相应摩擦力产生的载位移计算表

截面 4 5 6 7 8 0 M?1/I y/I 1?y 0M?/I 0M?y/I 0M?(y?1)/I -0.104 -0.664 -3.981 -8.659 -15.446 96 263.04 96 393.984 96 538.464 96 688.512 96 835.872 求和 3.74 5.104 6.609 8.172 -9.984 -63.744 -382.176 -831.264 -27.356 -261.605 -2143.625 -5961.825 -37.340 -325.349 -2525.801 -6793.089 -14393.695 -24075.275 9.707 -1482.816 -12910.879 -2769.984 -21305.291 ?1???s000M1M?M??S1.568 ds???I3.15?107?(?2769.984)??0.000137884EhIE?2???s000M2M?yM??S1.568 ds???(?21305.291)??0.00106053?7EhIEI3.15?10计算精度校核: ?1???2??0.001198?s?0(1?y)M??S1.568 ???(?24075.275)?0.001198?IEh3.15?107闭合差??0

6.3.4 墙底位移

单位弯矩作用下的转角:

??11??96?320?10?6(6-36) 6KIs0.3?10主动荷载作用下的转角:

00?ap?Msp?a??11324.778?320?10?6??3623928.96?10?6(6-37)

抗力及相应的摩擦力作用下的转角:

?a0??Ms0??a??15.446?320?10?6??4942.72?10?6(6-38)

6.4 解力法方程

计算力法方程系数为:

a11??11????(43.01?320)?10?6?363.01?10?6(6-39) a12??12?f???(137.56?8.707?320)?10?6?2923.8?10?6 a22??22?f2???(739.30?8.7072?320)?10?6?24999.09?10?6

0a10??1p??ap?(?1???a0?)?h??(238900?3623928.96?137.884?h?4942.72?h)?10?6 ??(3862828.96?5080.604?h)?10?60a20??2p?f?ap?(?2??f?a0?)?h??(1342700?8.707?3623928.96?1060.53?h?8.707?4942.72?h)?10?6 ??(32896249.45?44096.793?h)?10?6求解方程得:

X1?X2?a22a10?a12a20?731.7975?3.6475?h 2a12?a11a22a11a20?a12a10?1230.3096?2.1905?h 2a12?a11a226.5 计算主动荷载和被动荷载分别产生的衬砌内力

0?M?X?yX?Mp1p2pp?计算公式为:?(6-40) 0??Np?X2pcos??Np0??M??X1??yX2??M??0N?Xcos??N??2???(6-41)

表6.11主、被动荷载作用下衬砌弯矩计算表

截面 0 1 2 3 4 5 6 7 8 M0pX1p X?y [Mp]2p0 - -695.969 -211.348 520.807 0 M?X1? X2??y(?h)(?h)[M? ](?h)-452.862 531.7975 0 0 0 0 -3.6475 -3.6475 -3.6475 -3.6475 -3.6475 -3.6475 -3.6475 -3.6475 -3.6475 0 0.403 1.588 3.489 6.002 8.990 12.287 15.710 19.073 -3.648 -3.244 -2.059 -0.158 2.250 4.678 4.658 3.404 -0.021 -1201.389 731.7975 -226.377 -1835.119 731.7975 891.974 -2170.874 731.7975 1959.883 -2197.588 731.7975 3371.048 -1937.895 731.7975 5049.191 -1387.891 731.7975 6900.807 -766.960 731.7975 8823.780 -452.862 731.7975 10712.306 1905.258 -0.104 3843.094 -0.664 6244.714 -3.981 8788.618 -8.659 78.936 -15.446 表6.12主、被动荷载作用下衬砌轴力计算表

截面 0 1 2 3 4 5 6 7 8 0 NpX2pcos? 1230.960 ?N? p0 N?X2?cos? ?N?? 2.191 2.129 1.952 1.667 1.290 0.841 0.346 -0.169 -0.672 2.191 2.129 1.952 1.667 1.235 0.767 0.560 0.722 -0.269 0 1230.960 1721.300 1422.176 -10.596 -1371.325 2366.806 -51.889 1519.581 1230.960 0 0 0 0 -0.055 -0.074 0.214 0.891 0.403 524.807 1196.493 325.391 1096.785 -947.357 936.761 -2096.36 725.035 1894.117 472.689 -246.381 194.492 1614.365 -94.784 524.807 -377.905 6.6 最大抗力值的求解

首先求出最大抗力方向内的位移。考虑到接缝5的径向位移与水平方向有一定的偏离,因此修正后有:

?Mp?S????(y5?yi)sin?5?hp?5pEhI?(6-42) ?M??S???h???5??E?I(y5?yi)sin?5h?表6.13最大抗力位移值修正计算表