混凝土芯砂石桩振动沉管成桩效应及其累积特性研究
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摘要
混凝土芯砂石桩是由高强度预制混凝土芯桩和透水的砂石外壳组合而成,常采用振动沉管施工工艺进行软土地基加固。针对混凝土芯砂石桩新颖的桩型特点,对软黏土地基中振动沉管工艺引起的成桩效应及其特性进行了现场测试分析和理论计算研究。通过对远距离四桩施工全过程、全场地持续施工过程进行孔压、周边土体深层水平位移和混凝土芯桩桩身应力的实时跟踪监测,得到各监测量的变化规律和特点,揭示了振动沉管持续施工对各监测量消长变化的累积特性,指出振动沉管施工过程综合了静、动荷载对地基土的共同作用,体现荷载传递引起的能量在时间和空间上持续累积的特点。运用圆孔扩张理论对混凝土芯砂石桩沉管挤土的超静孔压和径向位移进行计算,探讨了理论解答与实际情况的适应性。
Concrete-core sand-gravel pile is composed of high strength precast concrete-core pile and permeable sand-gravel shell,and vibrating immersed tube technology is often used to reinforce soft soil foundation. In view of the characteristics of the new-type concrete-core sand-gravel pile,the compaction effect and its characteristics caused by the vibrating immersed tube technology in soft clay foundation are tested and analyzed on site and calculated theoretically. Through the whole process of long-distance construction of four piles and the continuous construction of the whole site,the real-time tracking and monitoring of the pore water pressure,the deep horizontal displacement of surrounding soil and the stress of concrete core pile body are conducted. The variation rules and characteristics of each monitoring quantity are obtained. This study reveals the effects of the cumulative characteristics of the continuous construction of vibrating sunken tube on the variation of each monitoring quantity,points out that the construction process of vibratory sunken tube integrates the combined action of static and dynamic load on foundation soil,and brings to light the characteristics of continuous accumulation of energy in space and time caused by load transfer. Based on the theory of cavity expansion,the excess pore water pressure and radial displacement of the concrete-core sand-gravel pile submerged pipe are calculated and the adaptability of theoretical solution to practical situation is discussed.
Concrete-core sand-gravel pile is composed of high strength precast concrete-core pile and permeable sand-gravel shell,and vibrating immersed tube technology is often used to reinforce soft soil foundation. In view of the characteristics of the new-type concrete-core sand-gravel pile,the compaction effect and its characteristics caused by the vibrating immersed tube technology in soft clay foundation are tested and analyzed on site and calculated theoretically. Through the whole process of long-distance construction of four piles and the continuous construction of the whole site,the real-time tracking and monitoring of the pore water pressure,the deep horizontal displacement of surrounding soil and the stress of concrete core pile body are conducted. The variation rules and characteristics of each monitoring quantity are obtained. This study reveals the effects of the cumulative characteristics of the continuous construction of vibrating sunken tube on the variation of each monitoring quantity,points out that the construction process of vibratory sunken tube integrates the combined action of static and dynamic load on foundation soil,and brings to light the characteristics of continuous accumulation of energy in space and time caused by load transfer. Based on the theory of cavity expansion,the excess pore water pressure and radial displacement of the concrete-core sand-gravel pile submerged pipe are calculated and the adaptability of theoretical solution to practical situation is discussed.
引文
[1]赵维炳,唐彤芝,蔡新,等.加固深厚软基的新方法-混凝土芯砂石桩复合地基法:中国,CN200610037621.2[P].2006-10-03.(ZHAO Weibing,TANG Tongzhi,CAI Xin,et al.A new method of improving soft soil:composite foundation with concrete-cored sand-gravel piles:China,CN200610037621.2[P].2006-10-03.(in Chinese))
[2]唐彤芝,赵维炳,关云飞,等.混凝土芯砂石桩复合地基加固深厚软基技术研究成果报告[R].南京:南京水利科学研究院,2007.(TANG Tongzhi,ZHAO Weibing,GUAN Yunfei,et al.The research report of the new technology on composite foundation with concrete-cored sand-gravel piles[R].Nanjing:Nanjing Hydraulic Research Institute,2007.(in Chinese))
[3]唐彤芝,赵维炳,陈俊生,等.高填土路堤荷载下混凝土芯砂石桩复合地基变形与承载力试验研究[J].岩土工程学报,2010,32(12):1829-1836.(TANG Tongzhi,ZHAO Weibing,CHEN Junsheng,et al.Experimental study on deformation and bearing capacity of composite foundation with concrete-cored sand-gravel piles under high embankment load[J].Chinese Journal of Geotechnical Engineering,2010,32(12):1829-1836.(in Chinese))
[4]程万钊,乐茂华,王富永,等.混凝土芯砂石桩复合地基加固堤防软基试验研究[J].水利学报,2007,38(增刊1):675-681.(CHENG Wanzhao,YUE Maohua,WANG Fuyong,et al.Field tests study of concrete-cored sand-gravel piles applied to strengthen embankment engineering[J].Journal of Hydraulic Engineering,2007,38(Suppl1):675-681.(in Chinese))
[5]唐彤芝,王芮文,尹建斌,等.混凝土芯砂石桩复合地基排水固结特性及试验研究[J].公路,2007(12):4-8.(TANGTongzhi,WANG Ruiwen,YIN Jianbin,et al.The research of consolidation and test with concrete-cored sand-gravel piles[J].Highway,2007(12):4-8.(in Chinese))
[6]叶观宝,张晴雯,赵维炳.混凝土芯砂石桩载荷试验及沉桩数值分析[J].长安大学学报(自然科学版),2015,35(1):41-48.(YE Guanbao,ZHANG Qingwen,ZHAO Weibing.Numerical analysis of loading test and pile penetration of concrete-core sand-gravel piles[J].Journal of Chang’an University(Natural Science Edition),2015,35(1):41-48.(in Chinese))
[7]杨燕伟,关云飞,李锦涛.混凝土芯砂石桩复合地基固结计算[J].水利水运工程学报,2016(3):46-52.(YANGYanwei,GUAN Yunfei,LI Jintao.A calculation method for consolidation of concrete core sand-gravel piles composite foundation under embankment[J].Hydro-Science and Engineering,2016(3):46-52.(in Chinese))
[8]鲁绪文,何宁,关秉洪,等.混凝土芯砂石桩的沉桩挤土效应及超孔隙水压力变化[J].水利水运工程学报,2006(4):41-45.(LU Xuwen,HE Ning,GUAN Binghong,et al.Soil squeezing effect of concrete-cored sand-gravel piles and excess pore water pressure dissipation[J].Hydro-Science and Engineering,2006(4):41-45.(in Chinese))
[9]俞缙,戚志博,蔡燕燕,等.低标号混凝土芯砂石桩复合地基固结计算方法[J].工程力学,2012,29(6):218-223,240.(YU Jin,QI Zhibo,CAI Yanyan,et al.Study on consolidation calculation of low-grade concrete-cored sand-gravel pile composite foundation[J].Engineering Mechanics,2012,29(6):218-223,240.(in Chinese))
[10]唐彤芝,赵维炳.基于圆孔扩张理论的CFG桩成桩效应计算分析[J].水运工程,2005(4):17-21.(TANG Tongzhi,ZHAO Weibing.Computational analysis for compaction effect of CFG pile based on the theory of cavity expansion[J].Port and Waterway Engineering,2005(4):17-21.(in Chinese))
[2]唐彤芝,赵维炳,关云飞,等.混凝土芯砂石桩复合地基加固深厚软基技术研究成果报告[R].南京:南京水利科学研究院,2007.(TANG Tongzhi,ZHAO Weibing,GUAN Yunfei,et al.The research report of the new technology on composite foundation with concrete-cored sand-gravel piles[R].Nanjing:Nanjing Hydraulic Research Institute,2007.(in Chinese))
[3]唐彤芝,赵维炳,陈俊生,等.高填土路堤荷载下混凝土芯砂石桩复合地基变形与承载力试验研究[J].岩土工程学报,2010,32(12):1829-1836.(TANG Tongzhi,ZHAO Weibing,CHEN Junsheng,et al.Experimental study on deformation and bearing capacity of composite foundation with concrete-cored sand-gravel piles under high embankment load[J].Chinese Journal of Geotechnical Engineering,2010,32(12):1829-1836.(in Chinese))
[4]程万钊,乐茂华,王富永,等.混凝土芯砂石桩复合地基加固堤防软基试验研究[J].水利学报,2007,38(增刊1):675-681.(CHENG Wanzhao,YUE Maohua,WANG Fuyong,et al.Field tests study of concrete-cored sand-gravel piles applied to strengthen embankment engineering[J].Journal of Hydraulic Engineering,2007,38(Suppl1):675-681.(in Chinese))
[5]唐彤芝,王芮文,尹建斌,等.混凝土芯砂石桩复合地基排水固结特性及试验研究[J].公路,2007(12):4-8.(TANGTongzhi,WANG Ruiwen,YIN Jianbin,et al.The research of consolidation and test with concrete-cored sand-gravel piles[J].Highway,2007(12):4-8.(in Chinese))
[6]叶观宝,张晴雯,赵维炳.混凝土芯砂石桩载荷试验及沉桩数值分析[J].长安大学学报(自然科学版),2015,35(1):41-48.(YE Guanbao,ZHANG Qingwen,ZHAO Weibing.Numerical analysis of loading test and pile penetration of concrete-core sand-gravel piles[J].Journal of Chang’an University(Natural Science Edition),2015,35(1):41-48.(in Chinese))
[7]杨燕伟,关云飞,李锦涛.混凝土芯砂石桩复合地基固结计算[J].水利水运工程学报,2016(3):46-52.(YANGYanwei,GUAN Yunfei,LI Jintao.A calculation method for consolidation of concrete core sand-gravel piles composite foundation under embankment[J].Hydro-Science and Engineering,2016(3):46-52.(in Chinese))
[8]鲁绪文,何宁,关秉洪,等.混凝土芯砂石桩的沉桩挤土效应及超孔隙水压力变化[J].水利水运工程学报,2006(4):41-45.(LU Xuwen,HE Ning,GUAN Binghong,et al.Soil squeezing effect of concrete-cored sand-gravel piles and excess pore water pressure dissipation[J].Hydro-Science and Engineering,2006(4):41-45.(in Chinese))
[9]俞缙,戚志博,蔡燕燕,等.低标号混凝土芯砂石桩复合地基固结计算方法[J].工程力学,2012,29(6):218-223,240.(YU Jin,QI Zhibo,CAI Yanyan,et al.Study on consolidation calculation of low-grade concrete-cored sand-gravel pile composite foundation[J].Engineering Mechanics,2012,29(6):218-223,240.(in Chinese))
[10]唐彤芝,赵维炳.基于圆孔扩张理论的CFG桩成桩效应计算分析[J].水运工程,2005(4):17-21.(TANG Tongzhi,ZHAO Weibing.Computational analysis for compaction effect of CFG pile based on the theory of cavity expansion[J].Port and Waterway Engineering,2005(4):17-21.(in Chinese))