结构干扰对煤棚表面风荷载影响的试验研究.pdf

为了确保大跨煤棚结构不被风荷载破坏，通过刚性模型测压风洞试验研究有、无干扰对煤棚结构风荷载的影响。结果表明：结构正对来流方向主要承受风压力作用，屋盖顶部主要承受风吸力作用，屋盖顶部风吸力最大；风荷载沿风向表现明显梯度，具有渐变性；施扰煤棚遮挡效应整体减小了受扰煤棚的风荷载，但也要注意干扰造成受扰煤棚局部风荷载变大的不利影响；当待测模型和干扰模型沿风向并列布置时，结构中间区域风荷载几乎不随跨向位置改变而改变，结构沿展向部分区域风荷载急剧变化。研究结果可为大跨煤棚结构抗风设计提供参考依据。关键词：煤棚；大跨结构；风洞试验；干扰效应；体型系数中图分类号：TU312+.1文献标志码：Adoi:10.6052/j.issn.1000-4750.2022.06.S029WINDTUNNELEXPERIMENTSTUDYONWINDLOADOFCOALSHEDSTRUCTUREBYINTERFERENCEEFFECTCHAIXiao-bing1,LIUQing-kuan1,2,3,ZHENGYun-fei4(1.SchoolofCivilEngineering,ShijiazhuangTiedaoUniversity,Shijiazhuang050043,China;2.StateKeyLaboratoryofMechanicalBehaviorandSystemSafetyofTrafficEngineeringStructures,ShijiazhuangTiedaoUniversity,Shijiazhuang050043,China;3.InnovationCenterforWindEngineeringandWindEnergyTechnologyofHebeiProvince,Shijiazhuang050043,China;4.DepartmentofRailwayEngineering,ShijiazhuangInstituteofRailwayTechnology,Shijiazhuang050062,China)Abstract:Inordertoensurethatthelarge-spancoalshedstructureisnotdamagedbywindload,aserieswindtunneltestswascarriedouttoobtainthewindshapecoefficientontheinterferenceeffectofcoalshedstructure.Theresultsshowthatthestructureismainlysubjectedtowindpressureinthedirectionofincomingflow,therooftopismainlysubjectedtowindsuction,andthewindsuctiononthetopoftheroofisthelargest.Thedistributionof wind load on the module shows an obvious gradient along the wind,and the wind load is gradual.Theshieldingeffectofinterferencecoalshedreducesthewindloadofthestructureasawhole,butweshouldalsopayattentiontothephenomenonthattheinterferencecausesthelocalwindloadtobecomelarger.Whenthemodeltobetestedandtheinterferencemodelarearrangedinparallelalongthewinddirection,thewindloadinthemiddleareaofthestructurealmostdoesnotchangewiththechangeofthespandirectionposition,andthewindloadinsomeareasofthestructurealongthedeploymentdirectionchangessharply.Theresultscanprovideareferenceforthewindresistancedesignoflarge-spancoalshedstructures.Keywords:coalshed;large-spanstructure;windtunneltest;interferenceeffect;shapecoefficient为了减少大气污染，煤炭多储存在封闭式煤棚内。煤棚大跨、轻柔的特点决定了风荷载是其结构设计的主要荷载12。目前国内外学者开展了大量煤棚抗风研究，孙一飞等3研究了全封闭状收稿日期：2022-06-19；修改日期：2023-01-11基金项目：河北省自然科学基金创新研究群体项目(E2022210078)；科技冬奥专项项目(21475402D)；河北省高端人才项目(冀办 201963 号)通讯作者：刘庆宽(1971)，男，河北人，教授，博士，主要从事结构和桥梁风致振动与控制研究(E-mail:).作者简介：柴晓兵(1993)，男，河北人，博士生，主要从事结构风致振动与控制研究(E-mail:);郑云飞(1985)，男，河北人，讲师，博士，主要从事结构和桥梁风致振动与控制研究(E-mail:).第40卷增刊Vol.40Suppl工程力学2023 年 6月June2023ENGINEERINGMECHANICS174态和半封闭状态对大跨煤棚风荷载的影响，得到内压对半封闭状煤棚风荷载影响较大的结论。NATALINI 等4通过风洞试验研究了几何尺寸对屋盖结构风荷载的影响。周暄毅等56研究了有、无干扰对煤棚结构风压分布和风致响应的影响，研究结果为煤棚结构抗风设计提供参考依据。张金龙等7分析干扰对结构受力以及结构表面风荷载体型系数的影响，干扰效应主要表现为遮挡效应和狭管效应。王鑫8通过研究两个相邻煤棚的风荷载，发现干扰可以减小结构风荷载。此外，用一定透空率的网板代替山墙成为一种新的煤棚结构形式9。双煤棚结构形式在实际工程中应用广泛，其干扰效应比较复杂。本文以两个相同尺寸条形煤棚为研究对象，通过刚性模型测压风洞试验研究有、无干扰两种状态下结构表面风荷载分布规律、结构风荷载随风向角的变化规律以及结构展向和跨向风荷载变化规律。1风洞试验介绍试验在石家庄铁道大学风洞实验室低速试验段进行10，低速试验段长 24m，宽 4.4m，高 3m。低速试验段最大风速 30m/s。1.1试验模型及风场此试验为刚性模型测压风洞试验，图 1 为风洞试验模型，该模型由 ABS 板制成，图 1 中正对来流方向下游模型为待测煤棚(受扰煤棚)，上游模型为干扰模型(施扰煤棚)。模型缩尺比 1150，最大阻塞度为 4.46%，模型共布置测点 1144 个，双面测压，测点布置如图 2 所示。试验采用 B 类地貌粗糙度类别风场，用尖劈和粗糙元模拟地表粗糙度特性。图 3 给出了平均风剖面和湍流度剖面模拟结果，可以看出，试验模拟得到的风剖面与我国建筑结构荷载规范11规定的理论风剖面吻合较好。1.2试验概况试验共设置 2 种工况：B 类地貌无干扰和 B类地貌有干扰。试验自由来流风速 10m/s，压力扫描阀采样频率 330Hz，采样时间 30s。风向角范围 0360，15间隔，定义如图 4 所示，风向角用 表示。1.3参数定义风压系数定义：Cpi,=Pi,PsPt,hPs=Pi,Ps0.5V2h(1)Cpi,Pi,式中：为 i 测点在 风向角下的风压系数；图1风洞试验模型Fig.1Windtunneltestmodel图2测点布置Fig.2Pressuremeasuringpoint0.00.20.40.60.81.00.00.20.40.60.81.0湍流度剖面平均风剖面剖面曲线UUgZZg=0.15无量纲风速U/Ug无量纲高度Z/Zg图3平均风剖面和湍流度剖面Fig.3Meanwindprofileandturbulenceprofile090270180待测模型干扰模型图4风向角定义Fig.4Definitionofwinddirectionangle工程力学175PsPt,hVhCpi,Cpi,为 i 测点在 风向角下风压；为参考点静压平均值；为参考高度 h 处总压；为空气密度，一般取 1.225kg/m3；为方便使用，参考高度取 h=10m，为 h 处的平均风速。平均风压系数表示的均值。静风压系数定义：Cpni,=Cpei,Cpii,(2)Cpni,Cpei,Cpii,Cpni,Cpni,式中：为 i 测点在 风向角下的静风压系数；和分别为 i 测点在 风向角下外测点风压系数和内测点风压系数。平均净风压系数表示的均值。体型系数定义：i,=Cpi,(Zi/h)2(3)ni,=Cpni,(Zi/h)2(4)i,ni,式中：()为 i 测点的体型系数(静压体型系数)；Zi为 i 测点所处的高度；为地貌粗糙度指数，B 类地貌 取值为 0.15。2结构表面风荷载分布规律选择施扰煤棚位于受扰煤棚上游工况进行分析，图 5 给出了 135风向角下无干扰和有干扰两种状态静压体型系数分布，整体来看，有、无干0.660.530.480.910.980.760.460.120.210.61.011.391.61.360.890.890.690.450.280.1100.120.280.4800.660.840.020.160.380.450.570.580.850.810.670.370.210.780.770.620.320.160.060.260.430.550.650.690.700.680.550.230.110.110.340.530.650.720.810.560.740.830.900.660.590.540.170.090.170.370.490.540.450.170.030.200.490.630.810.930.980.450.490.430.170.030.230.500.670.790.941.030.390.470.350.160.040.220.470.710.850.941.020.340.450.360.180.030.220.470.670.860.911.010.170.050.270.450.670.830.901.020.450.430.350.460.420.330.170.030.270.480.650.810.890.940.430.460.370.130.000.220.470.620.770.850.890.470.650.770.870.850.460.420.350.140.030.250.470.380.320.130.050.240.430.570.740.840.840.490.420.300.100.010.260.420.600.710.800.780.340.350.300.130.050.220.400.520.630.710.710.330.290.270.080.010.210.350.490.620.640.650.060.050.200.320.470.540.570.590.220.240.220.090.100.160.000.090.170.310.40.440.450.450.070.110.080.110.140.200.2800.310.300.350.330.280.300.240.250.270.280.280.390.390.280.250.240.190.270.330.350.250.450.400.240.20.160.150.220.330.430.210.440.440.200.170.160.170.230.380.470.190.460.400.230.160.160.130.240.420.550.160.420.470.270.180.170.210.260.460.600.230.520.500.230.240.200.160.290.510.670.130.510.550.230.220.210.210.350.550.730.190.640.570.240.220.230.270.370.580.780.160.610.540.260.260.220.300.460.650.840.120.760.600.290.270.270.330.500.690.850.190.690.590.310.30.260.390.580.760.930.250.740.490.330.280.310.490.670.820.960.400.630.500.360.340.380.550.710.880.930.490.610.460.440.410.500.620.770.910.980.690.690.550.530.570.580.660.800.870.930.750.750.690.660.650.680.700.770.840.890.850.810.710.670.660.650.680.730.760.780.760.840.740.680.640.630.660.650.690.740.870.800.700.660.560.610.630.670.690.620.830.740.680.620.620.590.650.720.860.890.800.680.610.590.600.600.600.680.801.120.550.040.150.420.470.710.40.070.200.310.410.50.310.010.250.390.440.230.030.420.170.10.290.420.590.460.170.260.110.090.050.760.840.840.950.940.940.630.690.730.790.910.930.540.60.660.790.820.670.680.360.470.530.560.550.330.390.450.070.110.240.410.370.410.490.470.320.330.420.470.460.330.370.360.370.330.370.340.300.290.310.320.340.320.240.250.230.250.270.310.300.270.450.490.50.510.650.630.470.520.400.430.440.460.460.430.370.370.370.400.360.380.360.320.340.330.330.310.340.300.350.32(b)有干扰0.18 0.21 0.160.820.850.550.190.250.651.071.471.731.721.380.720.680.440.190.070.060.300.450.670.911.090.140.290.470.530.630.670.510.430.310.060.020.290.250.130.020.080.210.350.480.580.670.700.010.020.020.070.060.200.340.480.600.660.730.390.570.670.750.020.020.030.080.010.100.230.170.150.100.050.050.020.210.330.510.660.730.300.290.220.130.130.020.170.310.410.580.710.400.400.230.170.110.030.120.30.450.540.660.510.500.360.290.170.080.120.280.470.530.660.370.240.060.070.270.430.540.670.630.560.440.680.580.460.420.290.110.090.260.440.550.640.610.620.510.400.340.170.060.240.420.530.620.100.270.430.570.620.610.530.450.430.330.120.550.440.390.400.320.1800.180.400.550.620.510.440.320.340.350.170.020.220.370.540.590.330.260.260.330.310.200.020.150.310.470.540.30.210.190.230.330.210.060.120.310.410.500.200.240.220.070.130.260.350.440.190.150.110.090.030.050.100.200.180.020.120.20.270.320.010.040.080.020.080.060.040.110.120.170.160.130.140.100.100.1020.130.110.190.190.130.120.110.100.180.210.220.060.20.140.060.060.040.070.190.30.360.050.150.120.040.030.040.090.230.370.40.020.180.090.060.010.040.080.270.440.500.030.120.120.090.030.060.130.300.460.530.020.170.130.050.090.100.100.300.490.580.000.150.140.040.070.110.150.350.500.620.060.250.170.040.070.130.220.350.500.640.070.210.190.090.120.130.250.410.530.660.070.330.240.120.140.180.270.420.530.630.120.330.290.160.180.180.320.450.570.690.190.380.260.210.180.230.390.520.610.690.310.370.340.270.250.280.420.550.670.670.380.440.360.360.340.390.470.600.700.750.550.560.450.460.490.480.520.620.700.750.610.600.550.550.530.530.570.630.720.760.680.640.560.530.490.510.520.580.650.720.630.660.590.540.500.480.520.530.610.720.690.660.580.520.450.500.550.620.680.690.70.640.560.500.520.530.610.680.871.040.660.570.500.500.510.560.620.750.841.040.370.010.160.310.130.080.280.040.160.190.080.240.230.010.110.020.270.190.010.060.180.030.020.240.320.040.070.130.190.170.240.400.600.810.890.880.880.360.660.710.760.840.870.210.580.640.740.750.630.600.140.330.490.520.460.060.220.380.190.080.110.310.160.20.260.260.130.140.220.240.210.150.190.180.20.160.180.140.140.140.160.160.170.150.110.110.100.110.120.150.140.120.170.220.250.210.380.380.280.320.190.230.240.290.280.260.190.190.210.260.210.230.220.160.180.190.190.150.190.160.190.19(a)无干扰图5135风向角下结构表面静压体型系数分布Fig.5Distributionofshapecoefficientat135winddirectionangle176工程力学扰两种状态下结构表面静压体型系数分布规律类似。正对来流方向，屋盖结构底部和一侧山墙风压为正，说明主要承受风压力作用；沿风向结构表面风压力逐渐向风吸力过度；处于背风面的山墙和屋盖风压为负，说明主要承受风吸力作用，且无论有无干扰，背风面山墙风荷载较小。在有干扰状态下，结构整体风荷载变小，说明遮挡效应减小了结构风荷载。另外，正对来流方向山墙与屋顶交接位置风荷载较大，在有干扰状态下此位置风荷载更大(局部测点在无干扰时静压体型系数为1.39，有干扰时静压体型系数为1.73)，因此，在进行结构设计时，要注意干扰造成局部风荷载变大的不利影响。图 6 给出了 180风向角下无干扰和有干扰两种状态静压体型系数分布，从图 6(a)可以看出，无干扰时正对来流方向煤棚屋盖底部风压为正，说明屋盖底部承受风压力作用；煤棚屋盖顶部风压为负，说明屋盖顶部承受风吸力作用。无干扰时正对来流方向屋盖底部风压力最大，顶部风吸力最大。气流在结构表面分离、再附，屋盖风荷载表现为风压力逐渐向风吸力过度，风荷载沿风向表现明显梯度，具有渐变性。两侧山墙主要受风吸力影响较大，沿风向表现为风吸力逐渐向风压力过度，且靠近来流方向山墙结构表面风吸力最大。此风向角下，有干扰时，受扰煤棚被施扰煤棚挡住，从图 6(b)可以看出，气流绕过干扰煤棚，受扰煤棚屋面底部角落极小区域承受风压力作用，其他较大区域均承受风吸力作用。对比0.28 0.34 0.340.260.550.490.210.030.150.330.470.540.580.550.750.900.860.490.270.020.330.510.660.720.700.020.320.660.770.920.891.061.051.030.590.310.871.161.090.630.340.080.410.710.891.021.001.221.181.080.580.320.060.470.790.991.071.120.781.011.111.121.241.161.110.560.330.120.471.181.181.040.560.290.100.540.811.041.151.101.171.171.020.570.280.120.530.810.971.101.051.101.160.940.570.230.120.490.820.991.030.990.991.150.960.610.240.100.480.760.990.990.970.580.240.150.450.760.950.990.981.191.130.951.181.110.930.580.250.140.510.750.940.990.930.941.161.000.560.280.090.500.740.931.000.940.510.800.961.070.991.221.151.000.60.250.131.191.090.970.610.250.110.460.720.991.101.071.171.130.980.60.310.110.460.790.991.141.101.151.101.020.670.300.060.420.700.921.061.091.241.101.050.660.370.030.360.660.920.991.050.640.340.020.300.610.810.880.941.061.091.040.860.920.990.60.290.040.290.510.650.720.750.480.530.570.340.100.080.300.450.500.590.560.470.380.600.540.470.410.020.050.090.120.190.300.370.520.610.580.030.10.070.120.170.220.30.430.570.690.070.120.100.120.140.180.270.430.630.740.090.210.130.160.110.140.190.440.690.860.050.190.180.200.120.120.190.370.670.860.000.140.140.110.130.110.090.250.580.850.040.060.110.060.060.060.070.180.470.800.030.020.030.010.010.040.060.090.410.730.060.070.010.020.010.010.020.080.300.700.110.040.030.030.010.010.000.030.240.640.120.090.030.020.010.050.010.020.250.660.120.080.060.000.040.030.010.050.290.690.010.050.040.020.000.020.010.060.350.690.030.030.040.060.010.020.020.090.370.770.030.140.110.100.100.050.050.150.450.810.020.160.180.150.120.100.100.250.590.880.060.250.180.160.150.110.160.360.660.890.050.200.140.140.130.120.210.400.680.900.010.090.090.110.070.160.260.410.620.720.030.070.1100.100.150.170.300.390.520.580.020.020.080.10.160.240.350.470.530.520.110.130.120.150.040.010.010.090.120.050.030.110.030.020.020.070.200.060.050.250.120.120.150.240.300.440.20.270.190.290.350.450.730.911.031.021.000.420.590.740.860.970.930.410.560.700.840.760.710.690.390.400.570.660.640.370.460.590.400.500.540.591.191.150.990.900.670.650.710.520.291.011.090.900.710.520.390.210.830.860.730.570.410.240.710.730.640.650.570.470.320.580.090.000.0100.040.040.100.040.130.060.010.000.030.000.170.070.030.040.050.070.110.220.140.100.160.300.210.350.310.210.19 0.21 0.190.200.230.180.200.210.150.090.050.170.330.410.340.270.230.330.340.290.090.070.260.390.480.350.150.140.320.520.590.490.350.340.420.460.400.440.400.490.520.390.140.140.380.590.670.560.370.340.460.520.370.120.160.430.600.740.140.410.580.700.400.190.210.250.420.300.110.170.060.020.130.250.210.000.160.380.550.620.010.040.060.000.130.120.050.170.300.460.540.100.090.150.070.000.030.050.190.320.380.450.040.080.150.090.040.000.080.170.310.340.410.090.050.070.060.150.260.350.410.000.090.150.010.110.160.060.000.000.060.150.290.370.430.010.020.080.050.100.090.000.130.300.420.490.050.160.340.520.610.180.050.040.050.170.110.350.190.110.210.320.290.150.080.370.600.730.590.500.360.460.550.400.190.160.440.710.830.930.730.680.750.700.460.170.160.460.720.860.900.720.690.720.680.440.140.190.490.670.840.610.510.340.100.210.440.600.740.780.660.610.650.550.610.540.430.290.040.190.350.480.580.400.390.490.440.270.150.020.170.260.370.420.270.220.410.320.280.270.100.100.090.140.260.450.610.740.690.520.130.170.110.130.250.370.430.500.580.620.180.210.130.100.130.230.380.520.640.670.110.270.100.080.050.160.360.610.760.810.020.180.110.080.030.120.350.610.760.810.010.160.090.040.090.170.240.510.700.770.010.110.090.050.080.140.200.420.570.670.080.150.100.040.070.110.170.270.410.550.080.060.100.080.100.070.110.20.310.450.040.100.080.070.080.080.080.130.230.360.040.070.100.080.090.050.080.110.220.360.030.060.050.090.050.060.10.140.240.370.110.060.120.090.080.060.090.160.320.400.060.120.100.090.070.090.110.240.40.530.010.180.090.080.100.080.150.340.510.620.040.140.110.080.090.100.230.460.650.730.070.140.080.070.080.120.280.510.680.760.030.100.090.090.110.140.310.480.640.760.050.110.090.100.090.190.280.420.540.600.080.120.100.100.130.150.270.350.460.500.080.070.090.110.130.180.280.420.480.500.040.030.070.090.170.200.070.050.030.100.170.280.070.070.120.200.330.100.100.140.120.140.180.340.510.250.200.280.170.260.330.070.090.100.040.160.220.060.090.010.130.200.250.100.000.110.200.270.210.230.060.040.130.170.170.30.210.160.310.220.130.130.580.390.200.110.010.010.020.030.050.700.430.230.140.050.050.020.830.430.190.120.090.040.740.430.580.420.230.170.110.370.030.000.020.070.130.070.020.080.060.060.050.080.050.080.090.060.070.120.120.160.220.120.130.160.300.230.200.340.340.32(b)有干扰(a)无干扰图6180风向角下结构表面静压体型系数分布Fig.6Distributionofshapecoefficientat180winddirectionangle工程力学177有、无干扰两种工况可以发现，遮挡效应增大了风吸力作用区域。此外，在有干扰情况下，结构风荷载明显减小，遮挡效应减小了结构风荷载，说明在 180风向角下干扰对结构抗风设计是有利的。3风荷载随风向角变化规律选取部分典型测点分析有、无干扰两种状态下结构表面风荷载随风向角的变化规律，图 7 给出部分典型测点布置图及编号，其中 A1F1 接近煤棚屋盖底部，A6F6 接近煤棚屋盖顶部。图 8 给出了与山墙交接位置屋盖部分测点 A1A6 有、无干扰两种状态下静压体型系数随风向角跨向展向A3H2H3G3G2G1H1A4A5A6B3B4B5B6C3C4A1A2B1B2C1C2C5C6D3D4D5D6E3E4E5E6F3F4D1D2E1E2F1F2F5F6图7局部典型测点布置图Fig.7Sometypicalpressuremeasuringpoints030 60 90 1201501802102402703003303601.501.251.000.750.500.250.000.250.500.751.00 无干扰 有干扰 无干扰 有干扰 无干扰 有干扰 无干扰 有干扰 无干扰 有干扰 无干扰 有干扰1.251.000.750.500.250.000.250.500.751.001.21.00.80.60.40.20.00.20.40.61.11.00.90.80.70.60.50.40.30.20.10.00.11.61.41.21.00.80.60.40.20.01.81.61.41.21.00.80.60.40.20.0风向角/()030 60 90 120150180210240270300330360风向角/()静压体型系数静压体型系数静压体型系数静压体型系数静压体型系数静压体型系数(a)A1030 60 90 120150180210240270300330360风向角/()(c)A3030 60 90 120150180210240270300330360风向角/()(d)A4030 60 90 120150180210240270300330360风向角/()(e)A5030 60 90 120150180210240270300330360风向角/()(f)A6(b)A2图8