管桩单桩竖向极限承载力的沉降预估研究
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摘要
为了更加精确地预估预应力管桩路基地基的沉降变形,基于慢速维持荷载理论,进行了路基预应力管桩的静载试验和试桩的Q-S曲线拟合,给出单桩沉降预估公式。同时,对拟合数据和实测数据进行了对比。研究结果表明:桩身完整性程度对单桩竖向极限承载力影响十分明显;指数函数模型对桩基的Q-S曲线具有较高的拟合精度;在保证成桩质量的前提下,给出的预估公式对桩基的沉降量具有较好的预测能力,且相对误差较小。
In order to accurately estimate the foundation settlement of subgrade with the prestressed pipe pile,based on the theory of slow maintenance loading method and combined with practical engineering,the static load test of prestressed pipe pile and the fitted Q-S curve with exponential function were conducted. The prediction formula of single pile settlement is given. At the same time,the fitting data were compared with the measured data. The results showed that the integrality of piles has a significant impact to the vertical ultimate bearing capacity. The functional model of exponential with a higher fitting precision for the Q-S curve. On the premise of guaranteeing the quality of piles,this fitted Q-S curve has a preferable predictive ability with smaller relative errors. The conclusions mentioned above can offer a reference to the design and construction of prestressed pipe pile in this region.
In order to accurately estimate the foundation settlement of subgrade with the prestressed pipe pile,based on the theory of slow maintenance loading method and combined with practical engineering,the static load test of prestressed pipe pile and the fitted Q-S curve with exponential function were conducted. The prediction formula of single pile settlement is given. At the same time,the fitting data were compared with the measured data. The results showed that the integrality of piles has a significant impact to the vertical ultimate bearing capacity. The functional model of exponential with a higher fitting precision for the Q-S curve. On the premise of guaranteeing the quality of piles,this fitted Q-S curve has a preferable predictive ability with smaller relative errors. The conclusions mentioned above can offer a reference to the design and construction of prestressed pipe pile in this region.
引文
[1]何旭龙.预应力管桩在铁路软土地基处理中的应用[J].路基工程,2017(1):174-178.HE X L. Application of prestressed pipe pile in railway soft soil foundation treatment[J]. Subgrade Engineering,2017(1):174-178.
[2] Kelevi sˇius K,Gabrielaitis L,Am sˇiejus J,et al. Study of bearing capacity of vibratory pile applying acceleration record[J]. Journal of Civil Engineering and Management,2014,20(1):142-148.
[3] Serrano A,Olalla C. Ultimate bearing capacity at the tip of a pile in rock,part 2:application[J]. International Journal of Rock Mechanics and Mining Sciences,2002,39(7):847-866.
[4] CAI C J,LIU S Y,TONG L Y,et al. Assessment of direct CPT and CPTU methods for predicting the ultimate bearing capacity of single piles[J].Engineering Geology,2008,104(3/4):211-222.
[5] Goncharov B V,Lopatin V P. Characteristics of the check of piles driven to a given elevation of their heads[J]. Soil Mechanics and Foundation Engineering,1978,15(2):104-108.
[6] JGJ 135—2007载体桩设计规程(附条文说明)[S].北京:中国建筑工业出版社,2007.JGJ 135—2007 Specification for Design of Ram-compacted Piles with Bearing Base[S]. Beijing:China Building Industry Press,2007.
[7] HE W,WANG GY,WNAG HH. Nonlinear calculating method of pile settlement[J]. Journal of Central South University of Technology,2008,5(S2):63-68.
[8] Baziar M H,Azizkandi A S,Kashkooli A. Prediction of pile settlement based on cone penetration test results:An ANN approach[J]. KSCE Journal of Civil Engineering,2015,19(1):98-106.
[9]国伟.单桩荷载—沉降曲线拟合线性回归法研究[J].长春工程学院学报(自然科学版),2015,16(2):21-23.GUO W. The study on single pile load-settlement curve fitting linear regression method[J]. Journal of Changchun Institute of Technology(Natural Science),2015,16(2):21-23.
[10]赵春风,李尚飞,卢嘉,等.完整指数函数拟合单桩荷载-沉降曲线的分析[J].同济大学学报(自然科学版),2010,38(4):486-492.ZHAO C F,LI S F,LU J,et al. Analysis of fitting loading settlement curves of single piles by integrated exponential function[J]. Journal of Tongji University(Natural Science),2010,38(4):486-492.
[2] Kelevi sˇius K,Gabrielaitis L,Am sˇiejus J,et al. Study of bearing capacity of vibratory pile applying acceleration record[J]. Journal of Civil Engineering and Management,2014,20(1):142-148.
[3] Serrano A,Olalla C. Ultimate bearing capacity at the tip of a pile in rock,part 2:application[J]. International Journal of Rock Mechanics and Mining Sciences,2002,39(7):847-866.
[4] CAI C J,LIU S Y,TONG L Y,et al. Assessment of direct CPT and CPTU methods for predicting the ultimate bearing capacity of single piles[J].Engineering Geology,2008,104(3/4):211-222.
[5] Goncharov B V,Lopatin V P. Characteristics of the check of piles driven to a given elevation of their heads[J]. Soil Mechanics and Foundation Engineering,1978,15(2):104-108.
[6] JGJ 135—2007载体桩设计规程(附条文说明)[S].北京:中国建筑工业出版社,2007.JGJ 135—2007 Specification for Design of Ram-compacted Piles with Bearing Base[S]. Beijing:China Building Industry Press,2007.
[7] HE W,WANG GY,WNAG HH. Nonlinear calculating method of pile settlement[J]. Journal of Central South University of Technology,2008,5(S2):63-68.
[8] Baziar M H,Azizkandi A S,Kashkooli A. Prediction of pile settlement based on cone penetration test results:An ANN approach[J]. KSCE Journal of Civil Engineering,2015,19(1):98-106.
[9]国伟.单桩荷载—沉降曲线拟合线性回归法研究[J].长春工程学院学报(自然科学版),2015,16(2):21-23.GUO W. The study on single pile load-settlement curve fitting linear regression method[J]. Journal of Changchun Institute of Technology(Natural Science),2015,16(2):21-23.
[10]赵春风,李尚飞,卢嘉,等.完整指数函数拟合单桩荷载-沉降曲线的分析[J].同济大学学报(自然科学版),2010,38(4):486-492.ZHAO C F,LI S F,LU J,et al. Analysis of fitting loading settlement curves of single piles by integrated exponential function[J]. Journal of Tongji University(Natural Science),2010,38(4):486-492.