隧道内力计算课程设计曲墙式衬砌计算文档格式.docx
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围岩容重,取=20KN/m3;
宽度影响系数,由式=1+i(B-5)计算,其中,B为隧道宽度,B=11.93+20.45+20.10=13.03m,式中0.10为一侧平均超挖量;
B5时,取i=0.1,=1+0.1*(13.03-5)=1.803所以围岩竖向荷载(考虑一衬后围岩释放变形取折减系数0.4)q=0.4516201.803*0.4259.632*0.4=103.853.2.2计算衬砌自重计算衬砌自重g=1/2*(d0+dn)*h=1/2(0.45+0.45)22=9.9根据我国复合式衬砌围岩压力现场量测数据和模型实验,并参考国内外有关资料,建议级围岩衬砌承受80%-60%的围岩压力,为安全储备这里取:
72.701)全部垂直荷载q=72.70+g=82.602)围岩水平均布压力e=0.4q=0.482.60=33.043.3衬砌几何要素衬砌几何要素3.3.1衬砌几何尺寸衬砌几何尺寸内轮廓线半径:
r1=7.000m,r2=5.900m内径r1,r2所画圆曲线的终点截面与竖直轴的夹角:
1=70.3432,2=108.7493拱顶截面厚度d0=0.45m,拱底截面厚度dn=0.45m。
3.3.1半拱轴线长度半拱轴线长度S及分段轴长及分段轴长SS=12.363m将半拱轴长度等分为8段,则S=S/8=12.363/8=1.545mS/Eh=1.545/0.25108=6.1810-8m3.3.3各分块截面中心几何要素各分块截面中心几何要素各分块截面与竖直轴的夹角及截面中心点的坐标可以由图3直接量得,具体数值见表2-1。
3.4计算位移计算位移3.4.1单位位移:
单位位移:
用辛普生法近似计算,按计算列表进行,单位位移的计算见表3-1。
表表3-1单位位移计算表面sincosxyd1/Iy/Iy2/I(1+y)2/I分系数1/30.0000.0001.0000.0000.0000.45131.6870.0000.000131.68714.4720.2500.9681.5310.1940.45131.68725.5474.956187.73828.9430.4840.8752.9640.7650.45131.687100.74177.067410.23543.4150.6870.724.2101.6760.45131.687220.708369.906943.00957.8870.8470.5325.1882.8690.45131.687377.8111083.9391971.24871.9160.9510.3105.8324.2520.45131.687559.9342380.8403632.39684.1940.9950.1016.1525.7640.45131.687759.0454375.1376024.91596.4720.994-0.1136.1437.3090.45131.687962.5027034.9289091.619108.7490.947-0.3215.8068.8170.45131.6871161.08610237.29912691.1591053.4983570.34820157.36828351.563注:
1.I截面惯性矩,I=bd3/12,b取单位长度2.不考虑轴力的影响。
单位位移值计算如下:
11=S/Eh1/I=6.1810-81053.498=65.106210-612=S/Ehy/I=6.1810-83570.348=220.647510-622=S/Ehy2/I=6.1810-820157.368=1245.725310-6计算精度校核:
11+212+22=(65.1062+2*220.6475+1245.7253)10-6=1752.126510-6SS=S/Eh(1+y)2/I=6.1810-828351.563=1752.126610-6闭合差=0.000110-603.4.2载位移载位移主动荷载在基本结构中引起的位移主动荷载在基本结构中引起的位移1)每一块上的作用力(竖向力Q、水平力E、自重力G),分别由下面各式求得,Qi=q*biEi=e*hiGi=(di-1+di)/2*S*rh其中:
bi衬砌外缘相邻两截面间的水平投影长度hi衬砌外缘相邻两截面间的竖直投影长度di接缝i的衬砌截面厚度均由图3直接量得,其值见表3-2。
各集中力均通过相应图形的形心。
图3衬砌结构计算图示(单位:
cm)表3-2载位移Mop计算表截面投影长度集中力S-Qaq-GagbhQGEaqagae00.0000.0000.0000.0000.0000.0000.0000.0000.0000.00011.5310.194126.46115.2966.4100.7650.7590.097-96.742-11.60921.4340.571118.44815.29618.8660.7170.6990.285-84.928-10.69231.2450.911102.83715.29630.0990.6230.5940.455-64.067-9.08640.9781.19380.78315.29639.4170.4890.4510.597-39.503-6.89850.6441.38353.19415.29645.6940.3220.2790.692-17.129-4.26760.3111.51225.68915.29649.956-0.1550.1190.7563.982-1.82070.0091.5450.74315.29651.047-0.004-0.0460.7730.0030.70480.0001.5080.00015.29649.8240.000-0.2090.7540.0003.197续表3-2-Gaei-1(Q+G)i-1Exyxy-xi-1(Q+G)-yi-1EMoip0.0000.0000.0000.0000.0000.0000.0000.0000.0000.000-0.6220.0000.0001.5310.1941.5310.1940.0000.000-108.973-5.377141.7566.4102.9640.7651.4330.571-203.136-3.660-416.766-13.695275.50025.2764.2101.6761.2460.911-343.273-23.026-869.913-23.532393.63355.3755.1882.8690.9781.193-384.973-66.062-1390.881-31.620489.71194.7925.8324.2520.6441.383-315.374-131.097-1890.368-37.767558.201140.4866.1525.7640.3201.512-178.624-212.415-2317.013-39.459599.185190.4436.1437.309-0.0091.5455.393-294.234-2644.606-37.568615.224241.4895.8068.817-0.3371.508207.330-364.166-2835.8132)外荷载在基本结构中产生的内力块上各集中力对下一接缝的力臂由图直接量得,分别记以aq、ae、ag。
内力按下式计算之:
弯矩:
轴力:
式中xi、yi相邻两接缝中心点的坐标增值。
xi=xi-xi-1yi=yi-yi-1Moip和Noip的计算见表3-2及表3-3。
表3-3载位移Noip计算表截面sincosi(Q+G)iEsin*i(Q+G)cos*iENop00.0000.0001.0000.0000.0000.0000.0000.000114.4720.2500.968141.7566.41035.4256.20629.219228.9430.4840.875275.50025.276133.32722.119111.208343.4150.6870.726393.63355.375270.53540.224230.311457.8870.8470.532489.71194.792414.78450.391364.393571.9160.9510.310558.201140.486530.62743.609487.018684.1940.9950.101599.185190.443596.11119.266576.844796.4720.994-0.113615.224241.489611.304-27.218638.5228108.7490.947-0.321630.519291.314597.060-93.636690.6963)主动荷载位移计算过程见表3-4。
表3-4主动荷载位移计算表截面Mp01/Iy/I1+yMp0/IyMp0/IMp0(1+y)/I积分系数1/300.000131.6870.0001.0000.0000.0000.00011-108.973131.68725.5471.194-14350.405-2783.979-17134.38442-416.766131.687100.7411.765-54882.723-41985.283-96868.00623-869.913131.687220.7082.676-114556.441-191996.594-306553.03544-1390.881131.687377.8113.869-183161.260-525489.656-708650.91625-1890.368131.687559.9345.252-248937.362-1058481.662-1307419.02446-2317.013131.687759.0456.764-305121.027-1758717.599-2063838.62627-2644.606131.687962.5028.309-348260.938-2545439.197-2893700.13548-2835.813131.6871161.0869.817-373440.375-3292623.783-3666064.1581-1454730.326-7713271.529-9168001.8551p=S/EhMp0/I=6.1810-8(-1454730.326)=-89902.33410-62p=S/EhMp0y/I=6.1810-8(-7713271.529)=-476680.18110-6计算精度校核Sp=1p+2pSp=S/EhMp0(1+y)/I因此,Sp=6.1810-8(-9168001.855)=-566582.515.51510-61p+2p=-(89902.334+476680.181)10-6=-566582.51510-6闭合差=0.000。
3.4.3载位移载位移单位弹性抗力及相应的摩擦力引起的位移单位弹性抗力及相应的摩擦力引起的位移1)各接缝处的抗力强度按假定拱部弹性抗力的上零点位于与垂直轴接近450的第3截面,3=43.4150=b;
最大抗力位于第5截面,5=71.9159=h;
拱部各截面抗力强度,按镰刀形分布,最大抗力值以上各截面抗力强度按下式计算:
i=h(coS2b-coS2i)/(coS2b-coS2h)计算得,3=0,4=0.5682h,5=h。
边墙截面弹性抗力计算公式为:
=h1-(yi/yh)2式中yi所求抗力截面与外轮廓线交点到最大截面抗力截面的垂直距离;
yh墙底外边缘c到最大抗力截面的垂直距离。
(yi和yh在图3中可量得)y6=1.559m;
y7=3.152m;
y8=4.707m;
则有:
6=h1-(1.559/4.707)2=0.8903h7=h1-(3.152/4.707)2=0.5516h8=0;
按比例将所求得的抗力绘在图4上。
2)各楔块上抗力集中力按下式近似计算:
式中,楔块i外缘长度,由图3量得。
的方向垂直于衬砌外缘,并通过楔块上抗力图形的形心。
3)抗力集中力与摩擦力之合力按近似计算:
式中围岩与衬砌间的摩擦系数。
取=0.2,则=1.0198其作用方向与抗力集中力的夹角为=arctg=11.301。
由于摩擦阻力的方向与衬砌位移方向相反,其方向朝上。
的作用点即为与衬砌外缘的交点。
将的方向线延长,使之交于竖直轴。
量取夹角k(自竖直轴反时针方向量度)。
将分解为水平与竖向两个分力:
RH=RiSinkRV=RicoSk以上计算例入表3-5中,并参见图3。
表3-5弹性抗力及摩擦力计算表截面i(h)(i-1+i)/2S外(h)R(h)ksink30.00000.0000.00000.00000.0000.00040.56820.2841.59870.463264.4390.90251.00000.7841.59871.278477.1090.97560.89030.9451.59871.540989.2121.00070.55160.7211.59871.1754101.0800.98180.00000.2761.59870.4497111.8880.928续表3-5截面coskRH(h)RV(h)vhRi(h)31.0000.0000.0000.00040.4310.4180.2000.2000.4180.45450.2231.2460.2850.4851.6641.25460.0141.5410.0210.5063.2051.5117-0.1921.153-0.2260.2804.3581.1538-0.3730.417-0.1680.1134.7760.4414)计算单位抗力图及其相应的摩擦力在基本结构中产生的内力弯矩轴力式中rKi-力Ri至接缝中心点K的力臂,由图3量得,计算见表3-6和表3-7。
表3-6M0计算表截面号R4=0.4632hR5=1.2784hR6=1.5409hR7=1.1754hR8=0.4497hMo(h)r4iR4r4ir5iR5r5ir6iR6r6ir7iR7r7ir8iR8r8i40.54550.253-0.25352.07140.9590.72000.920-1.88063.57331.6552.27032.9020.82801.276-5.83374.96342.2993.76944.8192.37293.6560.87921.033-11.80886.17562.8615.15856.5953.87275.9672.42392.8491.0520.473-18.745表3-7N0计算表截面号sincosRV(h)RH(h)sinRV(h)cosRH(h)No(h)457.88670.84670.53200.19990.41780.16920.2223-0.0531571.91590.95040.31100.48501.66400.46100.5175-0.0565684.19370.99480.10190.50623.20480.50360.32660.1770796.47150.9937-0.11190.28044.35830.2786-0.48750.76618108.74930.9472-0.32050.11274.77550.1068-1.53061.63745)单位抗力及相应摩擦力产生的载位移计算过程见表3-8。
表3-8单位抗力及相应摩擦力产生的载位移计算表截面号M0(h)1/Iy/I(1+y)M01/I(h)M0y/I(h)M0(1+y)/I(h)积分系数1/34-0.253131.6872377.8113.869-33.271-95.455-128.72625-1.880131.6872559.9345.252-247.564-1052.641-1300.20546-5.833131.6872759.0456.764-768.160-4427.678-5195.83827-11.808131.6872962.5028.309-1554.912-11364.855-12919.76348-18.745131.68721161.0869.817-2468.447-21764.304-24232.7441-3760.404-26826.852-30587.2481=S/EhM01/I=6.1810-8(-3760.404)=-232.393010-62=S/EhM0y/I=6.1810-8(-26826.852)=-1657.899510-6校核为:
1+2=-(232.3930+1657.8995)10-6=-1890.292510-6S=S/EhM0(1+y)/I=6.1810-8(-30587.248)=-1890.291910-6闭合差=0.000610-60。
综上计算得结构抗力图如图4图4结构抗力图3.4.4墙底(弹性地基上的刚性梁)位移墙底(弹性地基上的刚性梁)位移1)单位弯矩作用下的转角:
1=1/(KI8)=131.6872/0.18106=731.595610-62)主动荷载作用下的转角:
p=1M8p0=-2835.813731.595610-6=-2074668.31310-63)单位抗力及相应摩擦力作用下的转角:
=1M80=731.595610-6(-18.745)=-13713.759510-63.5解力法方程解力法方程衬砌矢高f=y8=8.817m计算力法方程的系数:
a11=11+1=(65.1062+731.5956)10-6=796.701810-6a12=12+f1=(220.6475+8.817*731.5956)10-6=6671.125910-6a22=22+f21=(1245.7253+8.817*8.817*731.5956)10-6=58119.593410-6a10=1p+p+(1+)h=-(89902.334+2074668.313+232.3930h+13713.7595h)10-6=-(2164570.647+13946.1525h)10-6a20=2p+fp+(2+f)h=-(476680.181+8.817*2074668.313+1657.8995h+8.817*13713.7595h)=-(18769030.7+122572.117h)10-6以上将单位抗力图及相应摩擦力产生的位移乘以h倍,即被动荷载的载位移。
求解方程:
X1=(a12a20-a22a10)/(a11a22-a122)=(329.6545-3.972h)其中:
X1p=329.65446,X1=-3.972X2=(a12a10-a11a20)/(a11a22-a122)=(285.0995+2.2059h)其中:
X2p=285.0995,X2=2.56483.6计算主动荷载和被动荷载(计算主动荷载和被动荷载(h=1)分别产生的衬砌内力)分别产生的衬砌内力计算公式为:
和计算过程列入表3-9和表3-10中。
表3-9主、被动荷载作用下衬砌弯矩计算表截面MopX1pyX2p*yMpMo(h)X1(h)X2*y(h)Mo(h)00.000329.6540.0000.000329.6540.000-3.9720.000-3.9721-108.973329.6540.19455.309275.9900.000-3.9720.498-3.4742-416.766329.6540.765218.101130.9900.000-3.9721.962-2.0103-869.913329.6541.676477.827-62.4320.000-3.9724.2990.3274-1390.881329.6542.869817.950-243.276-0.253-3.9727.3593.1345-1890.368329.6544.2521212.243-348.471-1.880-3.97210.9065.0546-2317.013329.6545.7641643.314-344.045-5.833-3.97214.7844.9797-2644.606329.6547.3092083.792-231.160-11.808-3.97218.7462.9678-2835.813329.6548.8172513.7227.564-18.745-3.97222.614-0.102表3-10主、被动荷载作用下衬砌轴力计算表截面NopcosaX2pcosNpNo(h)X2cos(h)N(h)00.0001.000285.099285.0990.0002.5652.565129.2190.968276.054305.2720.0002.4832.4832111.2080.875249.490360.6980.0002.2442.2443230.