悬臂式钢板桩和板桩稳定性计算计算书

悬臂式板桩和板桩稳定性计算计算书一、编制依据本计算书的编制参照建筑基坑支护技术规程（JGJ120-99），土力学与地基基础（清华大学出版社出版）等编制。二、参数信息重要性系数：1.00； 开挖深度度h：2.55m；基坑外侧水位深度hwa：3.4m； 基坑内侧水位深度hwp：0.80m；桩嵌入土深度hd：4m； 基坑边缘外荷载形式：无荷载悬臂板桩材料：20号槽钢； 弹性模量E：206000N/mm2；强度设计值fm：205N/mm2； 桩间距bs：0.10m；截面抵抗矩Wx：191.4cm3； 截面惯性矩Ix：1913.70cm4；基坑土层参数：序号 土名称 土厚度 坑壁土的重度 内摩擦角 内聚力 浮容重 (m) (kN/m3) () (kPa) (kN/m3)1 粘性土 4.3 18.2 7.5 12.2 18.2 2 粘性土 2.1 18.3 5.6 11.8 18.3 3 粉土 2.2 18.6 17.3 11.3 18.6 4 粘性土 5.3 19.3 6.5 37 19.3 三、土压力计算 1、水平荷载（1）、主动土压力系数：Ka1=tan2（45- 1/2）= tan2（45-7.5/2）=0.769；Ka2=tan2（45- 2/2）= tan2（45-7.5/2）=0.769；Ka3=tan2（45- 3/2）= tan2（45-5.6/2）=0.822；Ka4=tan2（45- 4/2）= tan2（45-17.3/2）=0.542；（2）、土压力、地下水以及地面附加荷载产生的水平荷载：第1层土：0 3.4米；a1上 = P1Ka1-2C1Ka10.5 = 00.769-212.20.7690.5 = -21.398kN/m；a1下 = (1h1+P1)Ka1-2C1Ka10.5 = 18.23.4+00.769-212.20.7690.5 = 26.193kN/m；第2层土：3.4 4.3米；H2 = ihi/2 = 61.88/18.2 = 3.4；a2上 = 2H2+P1+P2a2/(a2+2l2)Ka2-2C2Ka20.5 = 18.23.4+0+00.769-212.20.7690.5 = 26.193kN/m2；a2下 = 2H2+P1+P2a2/(a2+2l2)Ka2-2C2Ka20.5+h2Ka2+0.5wh22 = 18.23.4+0+00.769-212.20.7690.5+18.20.90.769+0.5100.92 = 42.841kN/m2；第3层土：4.3 6.4米；H3 = H2 = 3.4；a3上 = 3H3+P1+P2a2/(a2+2l2)Ka3-2C3Ka30.5+h3Ka3+0.5wh32 = 18.33.4+0+00.822-211.80.8220.5+18.30.90.822+0.5100.92 = 47.349kN/m2；a3下 = 3H3+P1+P2a2/(a2+2l2)Ka3-2C3Ka30.5+h3Ka3+0.5wh32 = 18.33.4+0+00.822-211.80.8220.5+18.330.822+0.51032 = 119.895kN/m2；第4层土：6.4 6.55米；H4 = H3 = 3.4；a4上 = 4H4+P1+P2a2/(a2+2l2)Ka4-2C4Ka40.5+h4Ka4+0.5wh42 = 18.63.4+0+00.542-211.30.5420.5+18.630.542+0.51032 = 92.837kN/m2；a4下 = 4H4+P1+P2a2/(a2+2l2)Ka4-2C4Ka40.5+h4Ka4+0.5wh42 = 18.63.4+0+00.542-211.30.5420.5+18.63.150.542+0.5103.152 = 98.961kN/m2；（3）、水平荷载：Z0=(a1下h1)/(a1上+ a1下)=(26.1933.4)/(21.39826.193)=1.871m；第1层土：Ea1=0.5Z0a1下=0.51.87126.193=24.507kN/m；作用位置：ha1=Z0/3+hi=1.871/3+3.15=3.774m；第2层土：Ea2=h2(a2上+a2下)/2=0.9(26.193+42.841)/2=31.065kN/m；作用位置：ha2=h2(2a2上+a2下)/(3a2上+3a2下)+hi=0.9(226.193+42.841)/(326.193+342.841)+2.25=2.664m；第3层土：Ea3=h3(a3上+a3下)/2=2.1(47.349+119.895)/2=175.606kN/m；作用位置：ha3=h3(2a3上+a3下)/(3a3上+3a3下)+hi=2.1(247.349+119.895)/(347.349+3119.895)+0.15=1.048m；第4层土：Ea4=h4(a4上+a4下)/2=0.15(92.837+98.961)/2=14.385kN/m；作用位置：ha4=h4(2a4上+a4下)/(3a4上+3a4下)+hi=0.15(292.837+98.961)/(392.837+398.961)+0=0.074m；土压力合力：Ea= Eai= 24.507+31.065+175.606+14.385=245.563kN/m；合力作用点：ha= hiEai/Ea= (24.5073.774+31.0652.664+175.6061.048+14.3850.074)/245.563=1.468m；2、水平抗力计算（1）、被动土压力系数：Kp1=tan2（45+ 1/2）= tan2（45+7.5/2）=1.3；Kp2=tan2（45+ 2/2）= tan2（45+7.5/2）=1.3；Kp3=tan2（45+ 3/2）= tan2（45+5.6/2）=1.216；Kp4=tan2（45+ 4/2）= tan2（45+17.3/2）=1.846；（2）、土压力、地下水产生的水平荷载：第1层土：2.55 3.35米；p1上 = 2C1Kp10.5 = 212.21.30.5 = 27.823kN/m；p1下 = 1h1Kp1+2C1Kp10.5 = 18.20.81.3+212.21.30.5 = 46.754kN/m；第2层土：3.35 4.3米；H2 = ihi/2 = 14.56/18.2 = 0.8；a2上 = 2H2Kp2+2C2Kp20.5 = 18.20.81.3+212.21.30.5 = 46.754kN/m；a2下 = 2H2Kp2+2C2Kp20.5+h2Kp2+0.5wh22 = 18.20.81.3+212.21.30.5+18.20.951.3+0.5100.952 = 73.748kN/m；第3层土：4.3 6.4米；H3 = H2 = 0.8；p3上 = 3H3Kp3+2C3Kp30.5+h3Kp3+0.5wh32 = 18.30.81.216+211.81.2160.5+18.30.951.216+0.5100.952 = 69.491kN/m；p3下 = 3H3Kp3+2C3Kp30.5+h3Kp3+0.5wh32 = 18.30.81.216+211.81.2160.5+18.33.051.216+0.5103.052 = 158.232kN/m；第4层土：6.4 6.55米；H4 = H3 = 0.8；p4上 = 4H4Kp4+2C4Kp40.5+h4Kp4+0.5wh42 = 18.60.81.846+211.31.8460.5+18.63.051.846+0.5103.052 = 209.448kN/m；p4下 = 4H4Kp4+2C4Kp40.5+h4Kp4+0.5wh42 = 18.60.81.846+211.31.8460.5+18.63.21.846+0.5103.22 = 219.287kN/m；（3）、水平荷载：第1层土：Ep1=h1(p1上+p1下)/2=0.8(27.823+46.754)/2=29.831kN/m；作用位置：hp1=h1(2p1上+p1下)/(3p1上+3p1下)+hi=0.8(227.823+46.754)/(327.823+346.754)+3.2=3.566m；第2层土：Ep2=h2(p2上+p2下)/2=0.95(46.754+73.748)/2=57.239kN/m；作用位置：hp2=h2(2p2上+p2下)/(3p2上+3p2下)+hi=0.95(246.754+73.748)/(346.754+373.748)+2.25=2.69m；第3层土：Ep3=h3(p3上+p3下)/2=2.1(69.491+158.232)/2=239.109kN/m；作用位置：hp3=h3(2p3上+p3下)/(3p3上+3p3下)+hi=2.1(269.491+158.232)/(369.491+3158.232)+0.15=1.064m；第4层土：Ep4=h4(p4上+p4下)/2=0.15(209.448+219.287)/2=32.155kN/m；作用位置：hp4=h4(2p4上+p4下)/(3p4上+3p4下)+hi=0.15(2209.448+219.287)/(3209.448+3219.287)+0=0.074m；土压力合力：Ep= Epi= 29.831+57.239+239.109+32.155=358.334kN/m；合力作用点：hp= hiEpi/Ep= (29.8313.566+57.2392.69+239.1091.064+32.1550.074)/358.334=1.443m；四、验算嵌固深度是否满足要求根据建筑基坑支护技术规程(JGJ 120-99)的要求，验证所假设的hd是否满足公式；hpEpj - 1.20haEai 01.44358.33-1.21.001.47245.56=84.59；满足公式要求！五、抗渗稳定性验算根据建筑基坑支护技术规程(JGJ 120-99)要求，此时可不进行抗渗稳定性验算！六、结构计算1、结构弯矩计算 弯矩图(kNm) 变形图(m)悬臂式支护结构弯矩Mc=15.23kNm；最大挠度为:0.03m；2、截面弯矩设计值确定：M=1.250Mc截面弯矩设计值M=1.251.0015.23=19.04；0-为重要性系数，按照建筑基坑支护技术规程（JGJ120-99）,表3.1.3可以选定。七、截面承载力计算1、材料的强度计算：max=M/(xWx)x-塑性发展系数，对于承受静力荷载和间接承受动力荷载的构件，偏于安全考虑，可取为1.0;Wx-材料的截面抵抗矩: 191.40 cm3max=M/(xWx)=19.04/(1.0191.4010-3)=99.47 MPamax=99.47 MPafm=205.00 MPa;经比较知，材料强度满足要求。