嵌固于多种地层的抗滑桩设计计算方法
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摘要
在采用抗滑桩加固边坡或滑坡的工程中通常会出现桩体嵌固段位于多种地层的情况,嵌固段桩体的受力对所加固坡体的稳定性有极为重要的影响。现行规范建议采用等效地基系数法计算桩体嵌固段,其计算结果往往与实际不符。针对实际工程中常见的嵌固段地层为3种及以下地层的情况,将其分为全土型、土土岩型、土岩岩型和全岩型4类,基于侧向受荷的弹性地基梁分析模型,采用嵌固段实际各地层的弹性抗力系数,考虑桩体嵌固段在各地层界面处的内力和变形连续性,给出了这4类典型情况下抗滑桩嵌固段的内力和位移计算公式。工程实例分析表明,本文提出的计算方法与数值模拟法、桩体有限差分算法的所得结果较为接近,但本文的计算过程更为简单,更便于实际操作。
Stabilizing piles embedded in various strata are extensively used for practical slope reinforcement or landslide control. Mechanical behaviors of the fixed segment in various strata have significant influence on stability of the reinforced slope. Equivalent ground coefficient of elastic resistance is suggested to solve this problem in current specifications in China. But the corresponding calculation results are not generally consistent with the actual pile responses. the slide-resistant piles are usually embedded in four basic types of strata including the soil-soil-soil type,soil-soil-rock type,soil-rock-rock type,and rock-rock-rock type. Based on analysis model of laterally loaded beam on elastic foundation,internal forces and displacements of the fixed segment are provided respectively with considering actual ground coefficient of elastic resistance of each strata and continuity of internal forces and displacements of the pile at interfaces of adjacent strata. Analysis of some practical engineering examples show that the calculation results obtained using the proposed method are in good agreement with those computed using numerical simulation method and finite difference algorithm for the pile.In particular,the computation procedure of the proposed method is easier and more convenient for practical application than the existing methods.
Stabilizing piles embedded in various strata are extensively used for practical slope reinforcement or landslide control. Mechanical behaviors of the fixed segment in various strata have significant influence on stability of the reinforced slope. Equivalent ground coefficient of elastic resistance is suggested to solve this problem in current specifications in China. But the corresponding calculation results are not generally consistent with the actual pile responses. the slide-resistant piles are usually embedded in four basic types of strata including the soil-soil-soil type,soil-soil-rock type,soil-rock-rock type,and rock-rock-rock type. Based on analysis model of laterally loaded beam on elastic foundation,internal forces and displacements of the fixed segment are provided respectively with considering actual ground coefficient of elastic resistance of each strata and continuity of internal forces and displacements of the pile at interfaces of adjacent strata. Analysis of some practical engineering examples show that the calculation results obtained using the proposed method are in good agreement with those computed using numerical simulation method and finite difference algorithm for the pile.In particular,the computation procedure of the proposed method is easier and more convenient for practical application than the existing methods.
引文
[1]铁道部第二勘察设计院.抗滑桩设计与计算[M].北京:中国铁道出版社,1983.The second institute of survey and design of Chinese Railway Ministry.Design and calculation of stabilizing piles[M].Beijing:China Railway Press,1983.
[2]公路桥涵地基与基础设计规范:JTG D63—2007[S].Specifications for design of ground base and foundation of highway bridges and culverts:JTG D63—2007[S].
[3]张浩,石名磊,郭院成,等.不平衡堆载作用下邻近结构桩的侧向受力机制[J].岩土工程学报,2016,38(12):2226-2235.ZHANG Hao,SHI Minglei,GUO Yuancheng,et al.Lateral mechanical behaviors of structural piles adjacent to imbalanced surcharge loads[J].Chinese Journal of Geotechnical Engineering,2016,38(12):2226-2235.
[4]鲁子爱.多层地基横向荷载桩Ks值分布研究[J].岩土工程学报,1988,10(1):48-56.LU Ziai.Study on modulus of subgrade reaction for lateral loaded piles in multiple layered foundation[J].Chinese Journal of Geotechnical Engineering,1988,10(1):48-56.
[5]董曼曼,王亮清,葛云峰,等.考虑滑床复合倾斜岩体综合地基系数的抗滑桩受力特征研究[J].岩土力学,2017,38(10):3000-3008.DONG Manman,WANG Liangqing,GE Yunfeng,et al.Study on mechanical characters of anti-sliding pile considering the integrated foundation coefficient of sliding bed on composite inclined rockmass[J].Rock and Soil Mechanics,2017,38(10):3000-3008.
[6]戴自航,陈林靖.多层地基中水平荷载桩计算m法的两种数值解[J].岩土工程学报,2007,29(5):690-696.DAI Zihang,CHEN Linjing.Two numerical solutions of laterally loaded piles installed in multi-layered soils by m method[J].Chinese Journal of Geotechnical Engineering,2007,29(5):690-696.
[7]POULOS H G.Behavior of laterally loaded piles:Isingle piles[J].Journal of Soil Mechanics and Foundation Division,ASCE,1971,97(SM5):711-731.
[8]GUO W D,LEE F H.Load transfer approach for laterally loaded piles[J].International Journal for Numerical and Analytical Methods for Geomechanics,2001,25(11):1101-1129.
[9]GUO Weidong.Pu-Based solutions for slope stabilizing piles[J].International Journal of Geomechanics,2013,13(3):292-310.
[10]CHORE H S,INGLE R K.SAWANT V A.Nonlinear analysis of pile groups subjected to lateral loads using‘p-y’curve[J].Interaction and Multiscale mechanics,2012,5(1):57-73.
[11]ALIASGER E.HAIDERALI,GOPAL MADABHUSHI.Evaluation of curve fitting techniques in deriving p-y curves for laterally loaded piles[J].Geotechnical and Geological Engineering,2016,34(5):1453-1473.
[12]CHOO Y W,KIM D.Experimental development of the p-y relationship for large-diameter offshore monopiles in sands:centrifuge tests[J].Journal of Geotechnical and Geoenvironmental Engineering,2016,142(1):04015058:1–12.
[13]凌道盛,任涛,王云岗.砂土地基斜桩水平承载特性p-y曲线法[J].岩土力学,2013,34(1):155-162.LING Daosheng,REN Tao,WANG Yungang.A p-y curve method for horizontal bearing characteristics of single batter pile in sands[J].Rock and Soil Mechanics,2013,34(1):155-162.
[14]ANDERSON J B,TOWNSEND F C,GRAJALES B.Case history evaluation of laterally loaded piles[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2003,129(3):187-196.
[15]KIM T K,KIM N K,LEE W J.et al.Experimental load-transfer curves of laterally loaded piles in NakDong river sand[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2004,130(4):416-425.
[16]詹红志,王亮清,王昌硕,等.考虑滑床不同地基系数的抗滑桩受力特征研究[J].岩土力学,2014,35(S2):250-256.ZHAN Hongzhi,WANG Liangqing,WANG Changshuo,et al.Study of mechanical characters of anti-sliding piles considering different foundation coefficients of sliding bed[J].Rock and Soil Mechanics,2014,35(S2):250-256.
[2]公路桥涵地基与基础设计规范:JTG D63—2007[S].Specifications for design of ground base and foundation of highway bridges and culverts:JTG D63—2007[S].
[3]张浩,石名磊,郭院成,等.不平衡堆载作用下邻近结构桩的侧向受力机制[J].岩土工程学报,2016,38(12):2226-2235.ZHANG Hao,SHI Minglei,GUO Yuancheng,et al.Lateral mechanical behaviors of structural piles adjacent to imbalanced surcharge loads[J].Chinese Journal of Geotechnical Engineering,2016,38(12):2226-2235.
[4]鲁子爱.多层地基横向荷载桩Ks值分布研究[J].岩土工程学报,1988,10(1):48-56.LU Ziai.Study on modulus of subgrade reaction for lateral loaded piles in multiple layered foundation[J].Chinese Journal of Geotechnical Engineering,1988,10(1):48-56.
[5]董曼曼,王亮清,葛云峰,等.考虑滑床复合倾斜岩体综合地基系数的抗滑桩受力特征研究[J].岩土力学,2017,38(10):3000-3008.DONG Manman,WANG Liangqing,GE Yunfeng,et al.Study on mechanical characters of anti-sliding pile considering the integrated foundation coefficient of sliding bed on composite inclined rockmass[J].Rock and Soil Mechanics,2017,38(10):3000-3008.
[6]戴自航,陈林靖.多层地基中水平荷载桩计算m法的两种数值解[J].岩土工程学报,2007,29(5):690-696.DAI Zihang,CHEN Linjing.Two numerical solutions of laterally loaded piles installed in multi-layered soils by m method[J].Chinese Journal of Geotechnical Engineering,2007,29(5):690-696.
[7]POULOS H G.Behavior of laterally loaded piles:Isingle piles[J].Journal of Soil Mechanics and Foundation Division,ASCE,1971,97(SM5):711-731.
[8]GUO W D,LEE F H.Load transfer approach for laterally loaded piles[J].International Journal for Numerical and Analytical Methods for Geomechanics,2001,25(11):1101-1129.
[9]GUO Weidong.Pu-Based solutions for slope stabilizing piles[J].International Journal of Geomechanics,2013,13(3):292-310.
[10]CHORE H S,INGLE R K.SAWANT V A.Nonlinear analysis of pile groups subjected to lateral loads using‘p-y’curve[J].Interaction and Multiscale mechanics,2012,5(1):57-73.
[11]ALIASGER E.HAIDERALI,GOPAL MADABHUSHI.Evaluation of curve fitting techniques in deriving p-y curves for laterally loaded piles[J].Geotechnical and Geological Engineering,2016,34(5):1453-1473.
[12]CHOO Y W,KIM D.Experimental development of the p-y relationship for large-diameter offshore monopiles in sands:centrifuge tests[J].Journal of Geotechnical and Geoenvironmental Engineering,2016,142(1):04015058:1–12.
[13]凌道盛,任涛,王云岗.砂土地基斜桩水平承载特性p-y曲线法[J].岩土力学,2013,34(1):155-162.LING Daosheng,REN Tao,WANG Yungang.A p-y curve method for horizontal bearing characteristics of single batter pile in sands[J].Rock and Soil Mechanics,2013,34(1):155-162.
[14]ANDERSON J B,TOWNSEND F C,GRAJALES B.Case history evaluation of laterally loaded piles[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2003,129(3):187-196.
[15]KIM T K,KIM N K,LEE W J.et al.Experimental load-transfer curves of laterally loaded piles in NakDong river sand[J].Journal of Geotechnical and Geoenvironmental Engineering,ASCE,2004,130(4):416-425.
[16]詹红志,王亮清,王昌硕,等.考虑滑床不同地基系数的抗滑桩受力特征研究[J].岩土力学,2014,35(S2):250-256.ZHAN Hongzhi,WANG Liangqing,WANG Changshuo,et al.Study of mechanical characters of anti-sliding piles considering different foundation coefficients of sliding bed[J].Rock and Soil Mechanics,2014,35(S2):250-256.