99某拱壩孔口應(yīng)力計(jì)算結(jié)果案例由于孔口尺寸遠(yuǎn)小于壩體尺寸，且孔口形心至壩體邊界的距離大于3倍孔口尺寸，可近似按彈性力學(xué)無限域中的小孔口計(jì)算。由于孔口處溫度應(yīng)力復(fù)雜，不做計(jì)算，所以只計(jì)算淺孔和中孔孔道的進(jìn)、出口斷面在壩體應(yīng)力、孔內(nèi)水壓力作用下，孔口0°方向、45°方向和90°方向上的應(yīng)力，具體計(jì)算見表3-6~表3-9。計(jì)算工況：正常蓄水位＋溫降孔口進(jìn)出口斷面應(yīng)力由前面計(jì)算得的拱冠梁、拱圈應(yīng)力按線性插值求得。壩身矩形孔口σ/Py、σ/τx、yσ/Px的應(yīng)力計(jì)算系數(shù)查表可得。將矩形孔口置于σx=Px，σy=Py和τxy的均勻應(yīng)力場(chǎng)中，測(cè)定6條射線上的正應(yīng)力，如圖3-1所示。首先，求出矩形孔口中心處的三個(gè)應(yīng)力σx、σy、τxy，然后將表中系數(shù)分別乘上這3個(gè)應(yīng)力，并將水壓、壩體應(yīng)力、溫度等作用結(jié)果疊加，即得各射線上的正應(yīng)力。溫度應(yīng)力是一個(gè)比較復(fù)雜的問題，在計(jì)算孔口配筋時(shí)可以不考慮溫度應(yīng)力，因?yàn)闇囟葢?yīng)力在混凝土產(chǎn)生裂縫時(shí)將釋放。不過考慮到配筋可以限制裂縫開展，保持壩的整體性，適當(dāng)配一些溫度鋼筋是有必要的。圖3-1 孔口處6個(gè)方向正應(yīng)力矩形孔口應(yīng)力計(jì)算，見表3-5~表3-9。泄洪孔進(jìn)出口孔寬b（m）梁向應(yīng)力Py（MPa）拱向應(yīng)力Px（MPa）內(nèi)水壓力P（MPa）淺孔進(jìn)口80.48611.10620.1727出口80.95952.14380.2453中孔進(jìn)口80.4902-0.01480.4387出口81.89061.51910.4856表3-5孔口處應(yīng)力場(chǎng)表3-6淺孔進(jìn)口斷面0°、45°和90°方向的應(yīng)力計(jì)算表（單位：MPa）d/b00.10.20.30.40.50.60.7d00.81.62.43.244.85.6壩體應(yīng)力Px作用σ/Px0°1.7801.7201.6501.5501.4501.3601.2801.23045°-1.1200.8900.7700.7000.6500.6100.59090°-0.920-0.700-0.490-0.320-0.180-0.090-0.0200.030σPx0°1.9691.9031.8251.7151.6041.5041.4161.36145°-1.2390.9850.8520.7740.7190.6750.65390°-1.018-0.774-0.542-0.354-0.199-0.100-0.0220.033內(nèi)水壓力P作用σP0°0.3070.2970.2850.2680.2500.2350.2210.21245°-0.1930.1540.1330.1210.1120.1050.10290°-0.159-0.121-0.085-0.055-0.031-0.016-0.0030.005σPx-σP0°1.6621.6061.5401.4471.3541.2701.1951.14845°-1.0460.8310.7190.6530.6070.5690.55190°-0.859-0.653-0.457-0.299-0.168-0.084-0.0190.028壩體應(yīng)力Py作用σ/Py0°-0.920-0.590-0.320-0.130-0.020-0.0400.0700.09045°-0.8500.7100.6400.5900.5800.5600.54090°1.3601.3401.3301.3101.2901.2601.2301.210σPy0°-0.447-0.287-0.156-0.063-0.010-0.0190.0340.04445°-0.4130.3450.3110.2870.2820.2720.26390°0.6610.6510.6470.6370.6270.6130.5980.588內(nèi)水壓力P作用σP0°-0.159-0.102-0.055-0.022-0.003-0.0070.0120.01645°-0.1470.1230.1110.1020.1000.0970.09390°0.2350.2310.2300.2260.2230.2180.2120.209σPy-σP0°-0.288-0.185-0.100-0.041-0.006-0.0130.0220.02845°-0.2660.2230.2010.1850.1820.1760.16990°0.4260.4200.4170.4110.4040.3950.3860.3790°方向總應(yīng)力1.3731.4211.4401.4061.3471.2571.2171.17645°方向總應(yīng)力-1.3121.0530.9190.8380.7890.7450.72090°方向總應(yīng)力-0.433-0.233-0.0410.1120.2360.3110.3670.407表3-7淺孔出口斷面0°、45°和90°方向的應(yīng)力計(jì)算表（單位：MPa）d/b00.10.20.30.40.50.60.7d00.81.62.43.244.85.6壩體應(yīng)力Px作用σ/Px0°1.7801.7201.6501.5501.4501.3601.2801.23045°-1.1200.8900.7700.7000.6500.6100.59090°-0.920-0.700-0.490-0.320-0.180-0.090-0.0200.030σPx0°3.8163.6873.5373.3233.1082.9162.7442.63745°-2.4011.9081.6511.5011.3931.3081.26590°-1.972-1.501-1.050-0.686-0.386-0.193-0.0430.064內(nèi)水壓力P作用σP0°0.4370.4220.4050.3800.3560.3340.3140.30245°-0.2750.2180.1890.1720.1590.1500.14590°0.226-0.172-0.120-0.078-0.044-0.022-0.0050.007σPx-σP0°3.3793.2653.1332.9432.7532.5822.4302.33545°-2.1261.6901.4621.3291.2341.1581.12090°-1.747-1.329-0.930-0.608-0.342-0.171-0.0380.057壩體應(yīng)力Py作用σ/Py0°-0.920-0.590-0.320-0.130-0.020-0.0400.0700.09045°-0.8500.7100.6400.5900.5800.5600.54090°1.3601.3401.3301.3101.2901.2601.2301.210σPy0°-0.883-0.566-0.307-0.125-0.019-0.0380.0670.08645°-0.8160.6810.6140.5660.5570.5370.51890°1.3051.2861.2761.2571.2381.2091.1801.161內(nèi)水壓力P作用σP0°-0.226-0.145-0.078-0.032-0.005-0.0100.0170.02245°-0.2080.1740.1570.1450.1420.1370.13290°0.3340.3290.3260.3210.3160.3090.3020.297σPy-σP0°-0.657-0.421-0.229-0.093-0.014-0.0290.0500.06445°-0.6070.5070.4570.4210.4140.4000.38690°0.9710.9570.9500.9360.9210.9000.8790.8640°方向總應(yīng)力2.7222.8442.9042.8502.7392.5532.4802.39945°方向總應(yīng)力-2.7342.1971.9191.7501.6481.5581.50690°方向總應(yīng)力-0.775-0.3720.0200.3280.5800.7290.8410.921表3-8 中孔進(jìn)口斷面0°、45°和90°方向的應(yīng)力計(jì)算表（單位：MPa）d/b00.10.20.30.40.50.60.7d00.81.62.43.244.85.6壩體應(yīng)力Px作用σ/Px0°1.7801.7201.6501.5501.4501.3601.2801.23045°-1.1200.8900.7700.7000.6500.6100.59090°-0.920-0.700-0.490-0.320-0.180-0.090-0.0200.030σPx0°-0.026-0.025-0.024-0.023-0.021-0.020-0.019-0.01845°--0.017-0.013-0.011-0.010-0.010-0.009-0.00990°0.0140.0100.0070.0050.0030.0010.0000.000內(nèi)水壓力P作用σP0°0.7810.7550.7240.6800.6360.5970.5620.54045°-0.4910.3900.3380.3070.2850.2680.25990°-0.404-0.307-0.215-0.140-0.079-0.039-0.0090.013σPx-σP0°-0.807-0.780-0.748-0.703-0.657-0.617-0.580-0.55845°--0.508-0.404-0.349-0.317-0.295-0.277-0.26890°0.4170.3170.2220.1450.0820.0410.009-0.014壩體應(yīng)力Py作用σ/Py0°-0.920-0.590-0.320-0.130-0.020-0.0400.0700.09045°-0.8500.7100.6400.5900.5800.5600.54090°1.3601.3401.3301.3101.2901.2601.2301.210σPy0°-0.451-0.289-0.157-0.064-0.010-0.0200.0340.04445°-0.4170.3480.3140.2890.2840.2750.26590°0.6670.6570.6520.6420.6320.6180.6030.593內(nèi)水壓力P作用σP0°-0.404-0.259-0.140-0.057-0.009-0.0180.0310.03945°-0.3730.3110.2810.2590.2540.2460.23790°0.5970.5880.5830.5750.5660.5530.5400.531σPy-σP0°-0.047-0.030-0.016-0.007-0.001-0.0020.0040.00545°-0.0440.0370.0330.0300.0300.0290.02890°0.0700.0690.0680.0670.0660.0650.0630.0620°方向總應(yīng)力-0.854-0.810-0.765-0.710-0.659-0.619-0.577-0.55345°方向總應(yīng)力--0.464-0.367-0.316-0.287-0.265-0.248-0.24090°方向總應(yīng)力0.4870.3860.2910.2130.1480.1060.0720.049表3-9中孔出口斷面0°、45°和90°方向的應(yīng)力計(jì)算表（單位：MPa）d/b00.10.20.30.40.50.60.7d00.81.62.43.244.85.6壩體應(yīng)力Px作用σ/Px0°1.7801.7201.6501.5501.4501.3601.2801.23045°-1.1200.8900.7700.7000.6500.6100.59090°-0.920-0.700-0.490-0.320-0.180-0.090-0.0200.030σPx0°2.7042.6132.5062.3552.2032.0661.9441.86845°-1.7011.3521.1701.0630.9870.9270.89690°-1.398-1.063-0.744-0.486-0.273-0.137-0.0300.046內(nèi)水壓力P作用σP0°0.8640.8350.8010.7530.7040.6600.6220.59745°-0.5440.4320.3740.3400.3160.2960.28790°-0.447-0.340-0.238-0.155-0.087-0.044-0.0100.015σPx-σP0°1.8401.7781.7051.6021.4991.4061.3231.27145°-1.1570.9200.7960.7230.6720.6300.61090°-0.951-0.723-0.506-0.331-0.186-0.093-0.0210.031壩體應(yīng)力Py作用σ/Py0°-0.920-0.590-0.320-0.130-0.020-0.0400.0700.09045°-0.8500.7100.6400.5900.5800.5600.54090°1.360