Influences of temperature change on axial force and deformation of inner support in deep foundation pits
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摘要: 温度变化对深基坑内支撑轴力和变形的影响明显,当支撑长度和断面尺寸较大时,温差引起的内支撑轴力和变形增量不容忽视。基于内支撑–支护桩–土相互作用且变形协调的前提,提出了采用弹性抗力法对单道支撑和多道支撑的温度应力简化计算方法。结合多道内支撑的深基坑工程案例,采用自主研发的地质灾害与工程结构安全自动化监测预警平台(简称监测平台),实现了深基坑内支撑系统温度变化影响的实时、连续、在线的自动化监测。监测结果验证了本文提出的多道水平支撑温度应力简化计算方法的可行性和可靠性;证明了监测平台是深基坑支撑轴力和变形实时、连续、在线最有效的监测方法。Abstract: The effects of temperature change on axial force and deformation of inner support in deep foundation pits are obvious, and the axial force and deformation increment of inner support caused by the temperature difference cannot be ignored when the support length and section size are large. Based on the premise of inner support-retaining pile-soil interaction and deformation coordination, a simplified method for temperature stress with one-layer support and multi-layer supports is proposed by using the elastic resistance method. Based on the case of deep foundation pit with multi-level supports, the integration platform is used to realize the real-time, continuous and online automatic monitoring of the effects of temperature change in the support system in deep foundation pits. The feasibility and reliability of the proposed simplified method for temperature stress of multi-level horizontal supports is verified by the monitoring results, and it is proved that the integration platform is the most effective monitoring method for the axial force and deformation of inner support in deep foundation pits.
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Keywords:
- deep foundation pit /
- inner support /
- temperature /
- axial force /
- deformation
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表 1 实测数据与理论计算结果对比表
Table 1 Comparison between measured data and calculated results
时间 实测轴力最大值Nmax/kN 实测轴力最小值Nmin/kN 支撑内温差 ΔT /℃单位温度支撑轴力增量Nt/(kN·℃-1) 6月17日 1600.29 1133.58 2.12 220.15 6月18日 1731.89 1394.08 1.80 187.67 6月19日 1866.71 1463.55 1.86 216.75 6月20日 2042.26 1635.76 2.02 201.24 6月21日 2125.76 1767.57 2.03 176.45 6月22日 2189.91 1867.32 1.84 162.92 6月23日 2293.05 1952.82 1.60 212.64 理论计算 1.00 232.14 表 2 实测数据与理论计算结果对比表
Table 2 Comparison between measured data and calculated results
时间 实测轴力最大值Nmax/kN 实测轴力最小值Nmin/kN 支撑内温差 ΔT /℃单位温度支撑轴力增量Nt/(kN·℃-1) 7月14日 3699.57 3383.70 1.51 209.19 7月15日 3804.06 3435.85 1.65 223.16 7月16日 3766.85 3449.24 1.66 191.33 7月17日 3836.41 3490.91 1.65 209.39 7月18日 3906.81 3546.86 1.67 215.54 7月19日 3910.63 3563.41 1.51 229.95 7月20日 3862.64 3585.43 1.06 261.52 理论计算 1.00 232.14 表 3 DC2-4支撑内部温度与大气温度实测值
Table 3 Measured values of internal temperature of support DC2-4 and air temperature
时间 支撑内部最低温度/℃ 测量时间 支撑内部最高温度/℃ 测量时间 6月17日 29.01(26.90) 09:12(05:30) 31.13(32.20) 15:13(14:16) 6月18日 30.21(27.40) 09:11(03:45) 32.01(31.90) 14:26(13:24) 6月19日 30.61(27.70) 07:56(05:30) 32.47(33.10) 17:24(16:43) 6月20日 31.12(27.80) 08:29(06:09) 33.14(33.20) 15:27(15:06) 6月21日 31.51(28.20) 08:18(03:35) 33.54(32.80) 15:24(14:14) 6月22日 31.87(28.60) 08:46(06:04) 33.85(33.10) 14:50(14:05) 6月23日 32.48(28.80) 09:10(05:22) 34.08(33.20) 14:45(13:19) 7月14日 31.44(28.80) 10:14(06:33) 32.95(34.90) 17:07(13:32) 7月15日 31.49(28.90) 08:22(05:01) 33.14(33.90) 16:18(12:58) 7月16日 31.17(28.20) 09:41(05:17) 32.83(33.50) 16:49(15:19) 7月17日 31.15(28.10) 09:30(03:06) 32.80(33.70) 17:14(15:11) 7月18日 31.35(28.90) 09:13(05:46) 33.02(33.60) 15:27(13:32) 7月19日 31.40(28.70) 10:54(03:22) 32.91(33.20) 16:33(14:58) 7月20日 31.30(28.30) 10:11(04:01) 32.36(33.10) 16:46(13:55) 注: 表中括号内数据为大气测站G1166实测大气温度值和测量时间。 -
[1] 建筑基坑支护技术规程:JGJ120—2012[S]. 2012. Technical Specification for Retaining and Protection of Building Foundation Excavations: JGJ 120-2012[S]. 2012. (in Chinese)
[2] 混凝土结构设计规范:GB50010—2010[S]. 2010. Code for Design of Concrete Structures: GB50010—2010[S]. 2010. (in Chinese)
[3] 钢结构设计规范:GB50017—2017[S]. 2017. Code for Design of Steel Structures: GB50017—2012[S]. 2017. (in Chinese)
[4] 张中普, 姚笑青. 某深基坑事故分析及技术处理[J]. 施工技术, 2005, 34(12): 72-73. doi: 10.3969/j.issn.1002-8498.2005.12.027 ZHANG Zhong-pu, YAO Xiao-qing. Accident analysis and technology dispose of certain deep foundation pit[J]. Construction Technology, 2005, 34(12): 72-73. (in Chinese) doi: 10.3969/j.issn.1002-8498.2005.12.027
[5] 郑刚, 顾晓鲁. 考虑支撑-围护桩-土相互作用的基坑支护水平支撑温度应力的简化分析法[J]. 土木工程学报, 2002, 35(3): 87-89, 108. doi: 10.3321/j.issn:1000-131X.2002.03.017 ZHENG Gang, GU Xiao-lu. Simple method for calculating temperature stress in horizontal strut of foundation pit considering strut-pile-soil interaction[J]. China Civil Engineering Journal, 2002, 35(3): 87-89, 108. (in Chinese) doi: 10.3321/j.issn:1000-131X.2002.03.017
[6] 林跃忠, 王铁成, 王来. 钢支撑温度应力对深基坑支护结构的影响研究[J]. 工业建筑, 2004(增刊): 1069-1074. https://cpfd.cnki.com.cn/Article/CPFDTOTAL-QXJX200407001181.htm LIN Yue-zhong, WANG Tie-cheng, WANG Lai. Study on the influence of temperature stress of steel support on the supporting structure of deep foundation pit[J]. Industrial Building, 2004(S0): 1069-1074. (in Chinese) https://cpfd.cnki.com.cn/Article/CPFDTOTAL-QXJX200407001181.htm
[7] 陆培毅, 韩丽君, 于勇. 基坑支护支撑温度应力的有限元分析[J]. 岩土力学, 2008, 29(5): 1290-1294. doi: 10.3969/j.issn.1000-7598.2008.05.027 LU Pei-yi, HAN Li-jun, YU Yong. Finite element analysis of temperature stress in strut of foundation pit[J]. Rock and Soil Mechanics, 2008, 29(5): 1290-1294. (in Chinese) doi: 10.3969/j.issn.1000-7598.2008.05.027
[8] 吴明, 孙鸣宇, 夏唐代, 等. 多层支撑深基坑中考虑支撑-围护桩-土相互作用的水平支撑温度应力简化计算方法[J]. 土木工程学报, 2009, 42(1): 91-94. doi: 10.3321/j.issn:1000-131X.2009.01.014 WU Ming, SUN Ming-yu, XIA Tang-dai, et al. Simplified method of calculating temperature stress in multi-layer struts for deep excavations considering strut-pile-soil interactions[J]. China Civil Engineering Journal, 2009, 42(1): 91-94. (in Chinese) doi: 10.3321/j.issn:1000-131X.2009.01.014
[9] 吴明, 彭建兵, 邓亚虹, 等. 改进的深基坑多层支撑温度应力计算方法[J]. 现代隧道技术, 2013, 50(1): 123-128. https://www.cnki.com.cn/Article/CJFDTOTAL-XDSD201301022.htm WU Ming, PENG Jian-bing, DENG Ya-hong, et al. Modified method for calculating temperature stress in multi-layer struts of a deep foundation pit[J]. Modern Tunnelling Technology, 2013, 50(1): 123-128.(in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-XDSD201301022.htm
[10] 艾智勇, 苏辉. 深基坑多层水平支撑温度应力的简化计算方法[J]. 同济大学学报(自然科学版), 2011, 39(2): 199-203. doi: 10.3969/j.issn.0253-374x.2011.02.008 AI Zhi-yong, SU Hui. A simplified method of calculating thermal Stress for multi-layered horizontal struts in deep excavations[J]. Journal of Tongji University(Natural Science), 2011, 39(2): 199-203. (in Chinese) doi: 10.3969/j.issn.0253-374x.2011.02.008
[11] 惠渊峰. 某地铁车站深基坑钢支撑温度应力计算与分析[J]. 建筑科学, 2012, 28(9): 101-103, 111. https://www.cnki.com.cn/Article/CJFDTOTAL-JZKX201209023.htm HUI Yuan-feng. The deep foundation pit steel brace temperature stresses analysis and calculation of subway station[J]. Building Science, 2012, 28(9): 101-103, 111. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JZKX201209023.htm
[12] CHAPMAN K R, CORDING E J, SCHNABEL H. Performance of a braced excavation in granular and cohesive soils[C]//ASCE Specially Conference on Performance of Earth and Earth-Supported Structures. Purdue University, 1972: 271-293.
[13] 陈锋, 艾英钵. 基坑钢支撑温度应力的弹性热力学解答[J]. 科学技术与工程, 2013, 13(1): 108-111. https://www.cnki.com.cn/Article/CJFDTOTAL-KXJS201301023.htm CHEN Feng, AI Ying-bo. Calculation of temperature stress of steel support in foundation pit using thermodynamics of elasticity[J]. Science Technology and Engineering, 2013, 13(1): 108-111. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-KXJS201301023.htm
[14] 范君宇. 深大基坑中水平支撑的温度内力与变形计算[J]. 山西建筑, 2014, 40(18): 59-62. https://www.cnki.com.cn/Article/CJFDTOTAL-JZSX201418033.htm FAN Jun-yu. In deep big hole excavated for building foundation level support temperature endogenic force and distortion computational method[J]. Shanxi Architecture, 2014, 40(18): 59-62. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-JZSX201418033.htm
[15] 向艳. 温度应力对深基坑支护结构内力与变形的影响研究[J]. 岩土工程学报, 2014, 37(增刊2): 64-69. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2014S2013.htm XIANG Yan. Influence of temperature stress on internal force and deformation of retaining structures for deep excavations[J]. Chinese Journal of Geotechnical Engineering, 2014, 37(S2): 64-69. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2014S2013.htm
[16] 刘畅, 张亚龙, 郑刚, 等. 改进的基坑支护水平支撑温度应力及水平位移的计算方法[J]. 岩土工程学报, 2015, 37(增刊1): 61-64. https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2015S1014.htm LIU Chang, ZHANG Ya-long, ZHENG Gang, et al. Modified method for calculating temperature stress and displacement in horizontal strut of foundation pits[J]. Chinese Journal of Geotechnical Engineering, 2015, 37(S1): 61-64. (in Chinese) https://www.cnki.com.cn/Article/CJFDTOTAL-YTGC2015S1014.htm
[17] 冉岸绿, 孙旻, 王浩, 等. 温度变化对新型钢支撑轴力的影响分析[C]//第十届全国基坑工程研讨会学术论文集. 兰州: 兰州理工大学, 2018: 675-678. RAN An-lu, SUN Min, WANG Hao, et al. Analysis of the influence of temperature change on the axial force of new steel support[C]//Academic Papers of the Tenth Nationwide Foundation Pit Engineering Seminar. Lanzhou: Lanzhou University of Technology, 2018: 675-678. (in Chinese)