静压有孔管桩超孔隙水压力消散的影响因素分析
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摘要
静压管桩因其质量可靠和施工过程中具有无噪声、无振动、应力小等诸多优点被广泛用于工程中。但静压管桩属于部分挤土桩,在沉桩过程中,桩周土体不仅会产生较大位移,而且会在短时间内形成较高的水压力。有孔管桩通过在桩身开孔能使土中自由水流入管腔,从而减小局部土体位移,加速超孔隙水压力的消散并降低其最大值。本文利用圆孔扩张理论,通过理论公式和工程算例的对比分析,得出有孔管桩沉桩超孔隙水压力随径向距离的增大呈对数衰减,随沉桩速率的加快不断增大,随深度的加深呈递增趋势,随开孔孔径的加大逐渐减小。可对控制管桩挤土效应提供可靠的理论依据。
Static pressure pipe-pile is widely used because of its reliable quality,noiseless and vibration-less characteristics,less construction stress and so on. But static pressure pipe pile belongs to partial squeezing soil pile,and the squeezing effect produced during pile sinking will not only produce huge disturbance to the soil around the pile,but also produce huge excess pore water pressure in a short time. The pipe-pile with holes can make the free water flow into the inner cavity of the pipe to reduce the displacement of soil,thus reducing the maximum value of excess pore water pressure and accelerating the dissipation of excess pore water pressure. In this paper,using the theory of cavity expansion,through the comparison of theoretical formula and an example,it shows that the excess pore water pressure decreases with the increase of radial distance; the excess pore water pressure increases with the increase of the velocity; the excess pore water pressure increases with depth deepening; the excess pore water pressure decreases with the increase of pore size. Thereby it can provide a reliable theoretical basis for controlling the soil compaction effects.
Static pressure pipe-pile is widely used because of its reliable quality,noiseless and vibration-less characteristics,less construction stress and so on. But static pressure pipe pile belongs to partial squeezing soil pile,and the squeezing effect produced during pile sinking will not only produce huge disturbance to the soil around the pile,but also produce huge excess pore water pressure in a short time. The pipe-pile with holes can make the free water flow into the inner cavity of the pipe to reduce the displacement of soil,thus reducing the maximum value of excess pore water pressure and accelerating the dissipation of excess pore water pressure. In this paper,using the theory of cavity expansion,through the comparison of theoretical formula and an example,it shows that the excess pore water pressure decreases with the increase of radial distance; the excess pore water pressure increases with the increase of the velocity; the excess pore water pressure increases with depth deepening; the excess pore water pressure decreases with the increase of pore size. Thereby it can provide a reliable theoretical basis for controlling the soil compaction effects.
引文
[1]丁金海,李继涛.挤土桩施工过程中的挤土效应及其机理分析[J].地质学刊,2011,35(3):317-321.(Ding Jinhai,Li Jitao.Analysis of soil squeezing effect and its mechanism in the construction of soil compaction pile[J].Journal of Geology,2011,35(3):317-321.(in Chinese))
[2]王恒.预应力管桩及挤土效应的研究[D].杭州:浙江大学,2002.(Wang Heng.Study on the effect of prestressed pipe pile and soil compaction[D].Hangzhou:Zhejiang University,2002.(in Chinese))
[3]张海霞.静压沉桩挤土效应分析[D].广州:华南理工大学,2010.(Zhang Haixia.Analysis of the squeezing effect of the static pile with static pressure[D].Guangzhou:South China University of Technology,2010.(in Chinese))
[4]雷金波,陈超群,章学俊.一种用于深厚软基处理的PTC型带孔管桩[P].中国专利:CN201620410U,2010-11-03.(Lei Jinbo,Chen Chaoqun,Zhang Xuejun.One for the deep soft foundation treatment of PTC type perforated pipe pile[P].China Patent:CN201620410U,2010-11-03.(in Chinese))
[5]马林,鲁子爱,李家华.沉桩过程土体超静孔隙水压力变化规律研究[J].科学技术与工程.2014,14(11):276-281.(Ma Lin,Lu Ziai,Li Jiahua.Pile soil pore water pressure variation of[J].Science Technology and Engineering,2014,14(11):276-281.(in Chinese))
[6]易飞.基于圆孔扩张理论的静压有孔管桩挤土效应分析[D].南昌:南昌航空大学,2015.(Yi Fei.Analysis of the effect of static pressure pipe pile with hole expansion based on the round hole expansion[D].Nanchang:Nanchang Hangkong University,2015.(in Chinese))
[7]韩同春,豆红强.柱孔扩张理论的空间轴对称解在沉桩挤土效应中的应用[J].岩石力学与工程学报,2012,5(增1):3209-3215.(Han Tongchun,Dou Hongqiang.Application of space axisymmetric solutions of cavity expansion to soil squeezing of pipe driving[J].Chinese Journal of Rock Mechanics and Engineering,2012,5(Supp.1):3209-3215.(in Chinese))
[8]姚笑青,胡中雄.饱和软土中沉桩引起的孔隙水压力估算[J].岩土力学,1997,18(4):30-35.(Yao Xiaoqing,Hu Zhongxiong.Estimating method for excess pore water pressure developed during pile driving[J].Rock and Soil Mechanics,1997,18(4):30-35.(in Chinese))
[9]唐世栋,何连生,傅纵.软土地基中单桩施工引起的超孔隙水压力[J].岩土力学,2002,23(6):725-729,732.(Tang Shidong,He Liansheng,Fu Zong.The super pore water pressure caused by single pile construction in soft soil foundation[J].Rock and Soil Mechanics,2002,23(6):725-729,732.(in Chinese))
[10]王旭东,王伟,宰金珉.沉桩引起的超孔隙水压力及其消散的三维解析解[J].南京工业大学学报,2002,24(6):16-19.(Wang Xudong,Wang Wei,Zai Jinmin.Three dimensional analysis of excess pore water pressure caused by pile[J].Journal of Nanjing University of Technology,2002,24(6):16-19.(in Chinese))
[2]王恒.预应力管桩及挤土效应的研究[D].杭州:浙江大学,2002.(Wang Heng.Study on the effect of prestressed pipe pile and soil compaction[D].Hangzhou:Zhejiang University,2002.(in Chinese))
[3]张海霞.静压沉桩挤土效应分析[D].广州:华南理工大学,2010.(Zhang Haixia.Analysis of the squeezing effect of the static pile with static pressure[D].Guangzhou:South China University of Technology,2010.(in Chinese))
[4]雷金波,陈超群,章学俊.一种用于深厚软基处理的PTC型带孔管桩[P].中国专利:CN201620410U,2010-11-03.(Lei Jinbo,Chen Chaoqun,Zhang Xuejun.One for the deep soft foundation treatment of PTC type perforated pipe pile[P].China Patent:CN201620410U,2010-11-03.(in Chinese))
[5]马林,鲁子爱,李家华.沉桩过程土体超静孔隙水压力变化规律研究[J].科学技术与工程.2014,14(11):276-281.(Ma Lin,Lu Ziai,Li Jiahua.Pile soil pore water pressure variation of[J].Science Technology and Engineering,2014,14(11):276-281.(in Chinese))
[6]易飞.基于圆孔扩张理论的静压有孔管桩挤土效应分析[D].南昌:南昌航空大学,2015.(Yi Fei.Analysis of the effect of static pressure pipe pile with hole expansion based on the round hole expansion[D].Nanchang:Nanchang Hangkong University,2015.(in Chinese))
[7]韩同春,豆红强.柱孔扩张理论的空间轴对称解在沉桩挤土效应中的应用[J].岩石力学与工程学报,2012,5(增1):3209-3215.(Han Tongchun,Dou Hongqiang.Application of space axisymmetric solutions of cavity expansion to soil squeezing of pipe driving[J].Chinese Journal of Rock Mechanics and Engineering,2012,5(Supp.1):3209-3215.(in Chinese))
[8]姚笑青,胡中雄.饱和软土中沉桩引起的孔隙水压力估算[J].岩土力学,1997,18(4):30-35.(Yao Xiaoqing,Hu Zhongxiong.Estimating method for excess pore water pressure developed during pile driving[J].Rock and Soil Mechanics,1997,18(4):30-35.(in Chinese))
[9]唐世栋,何连生,傅纵.软土地基中单桩施工引起的超孔隙水压力[J].岩土力学,2002,23(6):725-729,732.(Tang Shidong,He Liansheng,Fu Zong.The super pore water pressure caused by single pile construction in soft soil foundation[J].Rock and Soil Mechanics,2002,23(6):725-729,732.(in Chinese))
[10]王旭东,王伟,宰金珉.沉桩引起的超孔隙水压力及其消散的三维解析解[J].南京工业大学学报,2002,24(6):16-19.(Wang Xudong,Wang Wei,Zai Jinmin.Three dimensional analysis of excess pore water pressure caused by pile[J].Journal of Nanjing University of Technology,2002,24(6):16-19.(in Chinese))