基于沉桩模拟试验的装配式地下连续墙沉桩阻力评估方法
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摘要
装配式地下连续墙采用工厂预制、现场沉桩施工快速,具有施工文明、环境污染小的特点,是我国城市轨道交通基坑支护领域的重要发展方向。装配式地下连续墙现场施工的关键在于大截面预制板桩沉桩过程的控制,沉桩设计中需综合考虑沉桩阻力计算及预成槽泥浆状态的控制问题。针对装配式地下连续墙沉桩阻力的评估计算,通过模型桩室内沉桩试验系统研究了不同预成槽泥浆状态下的桩侧摩阻力、桩端阻力分布规律,提出了装配式地下连续墙自重沉桩及预压沉桩情形下的预成槽泥浆状态控制标准确定方法。结合预成槽模型桩室内沉桩试验结果,建立了装配式地下连续墙沉桩阻力评估模型,提出了预成槽泥浆状态控制范围,开发了预制桩沉桩可行性评估软件。其中,1.2m标准幅预制桩自重沉桩的泥浆密度不应超过1.15 g/cm~3,300 kN预压沉桩不应超过1.33 g/cm~3。
Prefabricated diaphragm wall is constructed through factory prefabrication and site jacking, which is more civilized and environmentally friendly, and it is an important research direction in rail transit pit support engineering in China. The key for the construction of prefabricated diaphragm wall is the jacking process control of the sheet pile with large section. During the design stage, it is particularly important to consider how to evaluate jacking resistance and perform slurry control. In order to evaluate the jacking resistance of prefabricated diaphragm wall, a series of model pile experiments is conducted. From which, lateral resistance and tip resistance of different preformed slurry situations are studied. With the experimental results, preformed slurry control standard is proposed for prefabricated diaphragm wall deadweight and preloading jacking. According to the final results of the model pile jacking experiments, a jacking resistance evaluation model for prefabricated diaphragm wall is established, the reliable control standard for preformed slurry situation is determined, and the related software is developed. Our results show that for prefabricated diaphragm wall deadweight jacking with 1.2 m width, the slurry density could not exceed 1.15 g/cm~3, and for preloading jacking with 30 ton additional pressure, the slurry density could not exceed 1.33 g/cm~3.
Prefabricated diaphragm wall is constructed through factory prefabrication and site jacking, which is more civilized and environmentally friendly, and it is an important research direction in rail transit pit support engineering in China. The key for the construction of prefabricated diaphragm wall is the jacking process control of the sheet pile with large section. During the design stage, it is particularly important to consider how to evaluate jacking resistance and perform slurry control. In order to evaluate the jacking resistance of prefabricated diaphragm wall, a series of model pile experiments is conducted. From which, lateral resistance and tip resistance of different preformed slurry situations are studied. With the experimental results, preformed slurry control standard is proposed for prefabricated diaphragm wall deadweight and preloading jacking. According to the final results of the model pile jacking experiments, a jacking resistance evaluation model for prefabricated diaphragm wall is established, the reliable control standard for preformed slurry situation is determined, and the related software is developed. Our results show that for prefabricated diaphragm wall deadweight jacking with 1.2 m width, the slurry density could not exceed 1.15 g/cm~3, and for preloading jacking with 30 ton additional pressure, the slurry density could not exceed 1.33 g/cm~3.
引文
[1]金亚兵.地连墙槽壁加固深度和宽度计算方法研究[J].岩土力学,2017,38(增刊2):273-278.JIN Ya-bing.A method for determination of reinforcement width and depth of trench face of diaphragm wall[J].Rock and Soil Mechanics,2017,38(Supp.2):273-278.
[2]张勣翔,许宏发,陈明雄.侧向静载下装配式复合墙模型试验研究[J].地下空间与工程学报,2011,7(4):695-699.ZHANG Ji-xiang,XU Hong-fa,CHEN Ming-xiong.Model test of assembled composite walls under lateral static load[J].Chinese Journal of Underground Space and Engineering,2011,7(4):695-699.
[3]欧孝夺,全守岳,彭远胜,等.新型装配式基坑支护结构设计与试验[J].岩土力学,2018,39(9):3433-3439.OU Xiao-duo,QUAN Shou-yue,PENG Yuan-sheng,et al.Design and test of new type prefabricated foundation pit supporting structure[J].Rock and Soil Mechanics,2018,39(9):3433-3439.
[4]辛翀.静压桩贯入阻力实测分析与数值模拟[D].青岛:青岛理工大学,2014.XIN Chong.The penetration resistance test analysis and numerical simulation for jacked piles[D].Qingdao:Qingdao Technological University,2014.
[5]王翔鹰,陈育民,江强,等.抗液化排水刚性桩沉桩过程的土压力响应[J].岩土力学,2018,39(6):2184-2192.WANG Xiang-ying,CHEN Yu-min,JIANG Qiang,et al.Soil pressures of the anti-liquefaction rigid-drainage pile during pile driving[J].Rock and Soil Mechanics,2018,39(6):2184-2192.
[6]陈伟.连锁空心方桩地下连排墙基坑支护成套技术的研究[D].北京:中国建筑科学研究院,2014.CHEN Wei.The complete set technology research on platoon-oriented wall of chain prestressed spun concrete square pile for excavation[D].Beijing:China Academy of Building Research,2014.
[7]李雨浓,李镜培,赵仲芳.基于静力触探试验的静压桩沉桩阻力估算[J].路基工程,2010(3):67-69.LI Yu-nong,LI Jing-pei,ZHAO Zhong-fang.Estimation of resistance of static pressure pile sinking based on cone penetration test[J].Subgrade Engineering,2010(3):67-69.
[8]张明义,邓安福.预制桩静力贯入层状地基的试验研究[J].岩土工程学报,2000,22(4):490-492.ZHANG Ming-yi,DENG An-fu.Experimental study on jacked precast piles in layered soil[J].Chinese Journal of Geotechnical Engineering,2000,22(4):490-492.
[9]GAVIN K G,O’KELLY B C.Effect of friction fatigue on pile capacity in dense sand[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(1):63-71.
[10]李林,李镜培,孙德安,等.天然饱和黏土地基静压桩承载力时效性研究[J].岩土力学,2017,38(9):2515-2522.LI Lin,LI Jing-pei,SUN De-an,et al.Time-dependence of bearing capacity of jacked piles in natural saturated clay[J].Rock and Soil Mechanics,2017,38(9):2515-2522.
[11]LEHANE B M,JARDINE R J,BOND A J,et al.Mechanisms of shaft friction in sand from instrumented pile tests[J].Journal of Geotechnical Engineering,1993,119(1):19-35.
[12]胡永强,汤连生,李兆源.静压桩桩-土界面滑动摩擦机制研究[J].岩土力学,2015,36(5):1288-1294.HU Yong-qiang,TANG Lian-sheng,LI Zhao-yuan.Mechanism of sliding friction at pile-soil interface of jacked pile[J].Rock and Soil Mechanics,2015,36(5):1288-1294.
[13]张明义,白晓宇,高强,等.黏性土中桩-土界面受力机制室内试验研究[J].岩土力学,2017,38(8):2167-2174.ZHANG Ming-yi,BAI Xiao-yu,GAO Qiang,et al.Experimental study on interfacial bearing mechanism of piles in cohesive soil[J].Rock and Soil Mechanics,2017,38(8):2167-2174.
[14]王士国.天津软土地区原位测试数据估算压桩阻力的研究与应用[D].北京:中国地质大学(北京),2014.WANG Shi-guo.Research and application on the estimation of sinking-pile resistance by the data derived from situ testing of soft soil in Tianjin area[D].Beijing:China University of Geosciences(Beijing),2014.
[15]刘金皊.上海地区静压沉桩可行性分析方法[J].上海建设科技,2013,5(5):57-59.LIU Jin-ling.Model test of assembled composite walls under lateral static load[J].Shanghai Construction Science&Technology,2013,5(5):57-59.
[16]樊向阳,顾国荣,黄宏伟.上海地区沉桩阻力估算方法分析探讨[J].力学季刊,2004,25(2):219-225.FAN Xiang-yang,GU Guo-rong,HUANG Hong-wei.Study of pile-sinking resistance estimation in Shanghai region[J].Chinese Quarterly of Mechanics,2004,25(2):219-225.
[2]张勣翔,许宏发,陈明雄.侧向静载下装配式复合墙模型试验研究[J].地下空间与工程学报,2011,7(4):695-699.ZHANG Ji-xiang,XU Hong-fa,CHEN Ming-xiong.Model test of assembled composite walls under lateral static load[J].Chinese Journal of Underground Space and Engineering,2011,7(4):695-699.
[3]欧孝夺,全守岳,彭远胜,等.新型装配式基坑支护结构设计与试验[J].岩土力学,2018,39(9):3433-3439.OU Xiao-duo,QUAN Shou-yue,PENG Yuan-sheng,et al.Design and test of new type prefabricated foundation pit supporting structure[J].Rock and Soil Mechanics,2018,39(9):3433-3439.
[4]辛翀.静压桩贯入阻力实测分析与数值模拟[D].青岛:青岛理工大学,2014.XIN Chong.The penetration resistance test analysis and numerical simulation for jacked piles[D].Qingdao:Qingdao Technological University,2014.
[5]王翔鹰,陈育民,江强,等.抗液化排水刚性桩沉桩过程的土压力响应[J].岩土力学,2018,39(6):2184-2192.WANG Xiang-ying,CHEN Yu-min,JIANG Qiang,et al.Soil pressures of the anti-liquefaction rigid-drainage pile during pile driving[J].Rock and Soil Mechanics,2018,39(6):2184-2192.
[6]陈伟.连锁空心方桩地下连排墙基坑支护成套技术的研究[D].北京:中国建筑科学研究院,2014.CHEN Wei.The complete set technology research on platoon-oriented wall of chain prestressed spun concrete square pile for excavation[D].Beijing:China Academy of Building Research,2014.
[7]李雨浓,李镜培,赵仲芳.基于静力触探试验的静压桩沉桩阻力估算[J].路基工程,2010(3):67-69.LI Yu-nong,LI Jing-pei,ZHAO Zhong-fang.Estimation of resistance of static pressure pile sinking based on cone penetration test[J].Subgrade Engineering,2010(3):67-69.
[8]张明义,邓安福.预制桩静力贯入层状地基的试验研究[J].岩土工程学报,2000,22(4):490-492.ZHANG Ming-yi,DENG An-fu.Experimental study on jacked precast piles in layered soil[J].Chinese Journal of Geotechnical Engineering,2000,22(4):490-492.
[9]GAVIN K G,O’KELLY B C.Effect of friction fatigue on pile capacity in dense sand[J].Journal of Geotechnical and Geoenvironmental Engineering,2007,133(1):63-71.
[10]李林,李镜培,孙德安,等.天然饱和黏土地基静压桩承载力时效性研究[J].岩土力学,2017,38(9):2515-2522.LI Lin,LI Jing-pei,SUN De-an,et al.Time-dependence of bearing capacity of jacked piles in natural saturated clay[J].Rock and Soil Mechanics,2017,38(9):2515-2522.
[11]LEHANE B M,JARDINE R J,BOND A J,et al.Mechanisms of shaft friction in sand from instrumented pile tests[J].Journal of Geotechnical Engineering,1993,119(1):19-35.
[12]胡永强,汤连生,李兆源.静压桩桩-土界面滑动摩擦机制研究[J].岩土力学,2015,36(5):1288-1294.HU Yong-qiang,TANG Lian-sheng,LI Zhao-yuan.Mechanism of sliding friction at pile-soil interface of jacked pile[J].Rock and Soil Mechanics,2015,36(5):1288-1294.
[13]张明义,白晓宇,高强,等.黏性土中桩-土界面受力机制室内试验研究[J].岩土力学,2017,38(8):2167-2174.ZHANG Ming-yi,BAI Xiao-yu,GAO Qiang,et al.Experimental study on interfacial bearing mechanism of piles in cohesive soil[J].Rock and Soil Mechanics,2017,38(8):2167-2174.
[14]王士国.天津软土地区原位测试数据估算压桩阻力的研究与应用[D].北京:中国地质大学(北京),2014.WANG Shi-guo.Research and application on the estimation of sinking-pile resistance by the data derived from situ testing of soft soil in Tianjin area[D].Beijing:China University of Geosciences(Beijing),2014.
[15]刘金皊.上海地区静压沉桩可行性分析方法[J].上海建设科技,2013,5(5):57-59.LIU Jin-ling.Model test of assembled composite walls under lateral static load[J].Shanghai Construction Science&Technology,2013,5(5):57-59.
[16]樊向阳,顾国荣,黄宏伟.上海地区沉桩阻力估算方法分析探讨[J].力学季刊,2004,25(2):219-225.FAN Xiang-yang,GU Guo-rong,HUANG Hong-wei.Study of pile-sinking resistance estimation in Shanghai region[J].Chinese Quarterly of Mechanics,2004,25(2):219-225.