基于极限分析的桩端岩层冲切分析

摘要
图/表
参考文献
相关文章 (15)

全文: PDF (576 KB) HTML (1 KB)
输出: BibTeX | EndNote (RIS)

摘要岩溶区桩基桩端岩层易发生冲切破坏。针对岩溶区岩体特点引进Hoek-Brown非线性岩石破坏强度准则，并推导得其剪应力的二次抛物线型表达式。基于极限分析上限法原理，确定冲切破坏体的功能方程，并通过变分求极值原理获得冲切破坏体的母线方程，进一步通过微分得到桩端岩层抗冲切安全厚度计算公式。结合岩溶区桩基实践，分析抗冲切安全厚度影响因素的取值范围并进行参数分析，结果表明：(1) 冲切破坏体上下直径比d1/d随岩体地质力学分类指标RMR值的增大呈非线性减小，说明岩体质量好的岩溶顶板其冲切所形成的锥形旋转体底部直径小，反之，旋转体底部直径大；(2) 根据不同的d1/d及RMR值，初始冲切角为24°～42°；(3) 厚径比h/d随RMR的增大呈非线性减小，表明岩体质量越好，所需安全厚度也越小；在岩体质量较好(RMR＞65)的情况下，h/d基本在2.5以下。

	服务

	把本文推荐给朋友
	加入我的书架
	加入引用管理器
	E-mail Alert
	RSS
	作者相关文章

关键词 ：桩基础, 冲切破坏, 极限分析, 功能方程, 安全厚度

Abstract：The rock stratum at pile tip is prone to punching failare for pile foundation in karst region. The Hoek-Brown nonlinear rock strength criterion has been introduced according to the characteristics of rock mass in the karst region；and then the shear stress of quadratic parabolic expression was obtained. The work-energy equation of punching failure body was established using limit analysis method. Then the generatrix equation of punching failure body was obtained through the variational extremum principle. Furthermore，the calculation formula of safe thickness for the rock stratum anti-punching failure was obtained by differential equation. Combined with the practice of pile foundation in karst area，the value range of main resistant punching shear safety thickness factors affecting were analyzed. Parameter analysis shows that：(1) The top and bottom diameter ratio d1/d of punching failure body decreased nonlinearly along with the increase of RMR value；in other words the bottom conical rotor diameter of punching failure which formed by the good karst roof of rock mass quality is small. Conversely，the greater the diameter at the bottom of the body of revolution. (2) According to the different d1/d and RMR values，the ranges of initial punching angle is between 24°–42°. (3) The ratio of thickness to diameter h/d decreases nonlinearly along with the increase of RMR. That is to say the better the rock mass quality，the smaller the safe thickness. When the rock mass quality is good(RMR＞65)，the safety thickness h/d is lower than 2.5.

Key words： pile foundations punching failure limit analysis work-energy equations safe thickness

收稿日期: 2013-05-07

引用本文:

雷勇，陈秋南，马缤辉. 基于极限分析的桩端岩层冲切分析[J]. 岩石力学与工程学报, 2014, 33(3): 631-638.
LEI Yong，CHEN Qiunan，MA Binhui. PUNCHING ANALYSIS OF ROCK AT PILE TIP BASE ON LIMIT ANALYSIS. , 2014, 33(3): 631-638.

链接本文:

https://rockmech.whrsm.ac.cn/CN/Y2014/V33/I3/631

[1]	黄生根，梅世龙，龚维明. 南盘江特大桥岩溶桩基承载特性的试验研究[J]. 岩石力学与工程学报，2004，23(5)：809-813.(HUANG Shenggen，MEI Shilong，GONG Weiming. Testing study on bearing behavior of piles for Nanpan river great bridge in karst area[J]. Chinese Journal of Rock Mechanics and Engineering，2004，23(5)：809-813.(in Chinese))
[2]	唐孟雄，陈如桂，陈伟. CRG桩在岩溶地层的试验研究[J]. 岩石力学与工程学报，2006，25(增2)：3 441-3 448.(TANG Mengxiong，CHEN Rugui，CHEN Wei. Experimental study on CRG piles in karst strata[J]. Chinese Journal of Rock Mechanics and Engineering，2006，25(Supp.2)：3 441-3 448.(in Chinese)) " target="_blank">
[3]	黎斌，范秋雁，秦凤荣. 岩溶地区溶洞顶板稳定性分析[J]. 岩石力学与工程学报，2002，21(4)：532-536.(LI Bin，FAN Qiuyan，QIN Fengrong. Analysis of roof stability of karst cave in karst areas[J]. Chinese Journal of Rock Mechanics and Engineering，2002，21(4)：532-536.(in Chinese))
[4]	李炳行，肖尚惠，莫孙庆. 岩溶地区嵌岩桩桩端岩体临空面稳定性初步探讨[J]. 岩石力学与工程学报，2003，22(4)：633-635.(LI Bingxing，XIAO Shanghui，MO Sunqing. Discussion about the stability of rock mass free face on the tip of rock sockted pile in carst region[J]. Chinese Journal of Rock Mechanics and Engineering，2003，22(4)：633-635.(in Chinese))
[5]	《工程地质手册》编委会. 工程地质手册[M]. 4版. 北京：中国建筑工业出版社，2007：530-531.(Editorial Board of Engineering Geology Manual. Engineering geology manual[M]. 4th ed. Beijing：China Architecture and Building Press，2007：530-531.(in Chinese)) " target="_blank">
[6]	WYLLIE D C. Foundations on rock[M]. London：Chapman and Hall，1992：36-46. " target="_blank">
[7]	张慧乐，张智浩，王述红，等. 岩溶区嵌岩桩的试验研究与分析[J]. 土木工程学报，2013，46(1)：92-103.(ZHANG Huile，ZHANG Zhihao，WANG Shuhong，et al. Experimental study and analysis of rock-socketed pile in karst area[J]. China Civil Engineering Journal，2013，46(1)：92-103.(in Chinese)) " target="_blank">
[8]	赵明华，曹文贵，何鹏祥，等. 岩溶及采空区桥梁桩基桩端岩层安全厚度研究[J]. 岩土力学，2004，25(1)：64-68.(ZHAO Minghua，CAO Wengui，HE Pengxiang，et al. Study on safe thickness of rock mass at end of bridge foundation?s pile in karst and worked-out mine area[J]. Rock and Soil Mechanics，2004，25(1)：64-68.(in Chinese))
[9]	赵明华，袁腾方，黎莉，等. 岩溶区桩端持力岩层安全厚度计算研究[J]. 公路，2003，1(1)：124-128.(ZHAO Minghua，YUAN Tengfang，LI Li，et al. Computation study on safety thickness of bearing rock strata at ends of piles in karst region[J]. Highway，2003，1(1)：124-128.(in Chinese))
[10]	WALRAVEN J C. Fundamental analysis of aggregate interlock[J]. ASCE Journal of the Structural Division，1981，107(ST11)：2 245-2 270. " target="_blank">
[11]	赵明华，雷勇，张锐. 岩溶区桩基冲切破坏模式及安全厚度研究[J]. 岩土力学，2012，33(2)：524-530.(ZHAO Minghua，LEI Yong，ZHANG Rui. Study of punching failure mode and safe thickness of pile foundation in karst region[J]. Rock and Soil Mechanics，2012，33(2)：524-530.(in Chinese))
[12]	尤明庆. 岩石强度准则的数学形式和参数确定的研究[J]. 岩石力学与工程学报，2010，29(11)：2 172-2 184.(YOU Mingqing. Study of mathematical equation and parameter determination of strength criteria for rock[J]. Chinese Journal of Rock Mechanics and Engineering，2010，29(11)：2 172-2 184.(in Chinese))
[13]	HOEK E，BROWN E T. Practical estimate the rock mass strength[J]. International Journal of Rock Mechanics and Mining Sciences，1997，34(8)：1 165-1 186. " target="_blank">
[14]	JIMENEZ R，SERRANO A，OLALLA C. Linearization of the Hoek and Brown rock failure criterion for tunnelling in elasto-plastic rock masses[J]. International Journal of Rock Mechanics and Mining Sciences，2008，45(7)：1 153-1 163. " target="_blank">
[15]	YANG X L，LI L，YIN J H. Stability analysis of rock slopes with a modified Hoek-Brown failure criterion[J]. International Journal for Numerical and Analytical Methods in Geomechanics，2004，28(2)：181-190. " target="_blank">
[16]	MERIFIELD R S，LYAMIN A V，SLOAN S W. Limit analysis solutions for the bearing capacity of rock masses using the generalised Hoek-Brown criterion[J]. International Journal of Rock Mechanics and Mining Sciences，2006，43(6)：920-937. " target="_blank">
[17]	FRALDI M，GUARRACINO F. Limit analysis of collapse mechanisms in cavities and tunnels according to the Hoek-Brown failure criterion[J]. International Journal of Rock Mechanics and Mining Sciences，2009，46(4)：665-673.
[18]	CHEN W F. Limit analysis and soil plasticity[M]. Amsterdam：Elsevier Science，1975：28-63. " target="_blank">
[19]	SERRANO A，OLALLA C. Tensile resistance of rock anchors[J]. International Journal of Rock Mechanics and Mining Sciences，1999，36(4)：449-474. " target="_blank">
[20]	HOEK E，BROWN E T. The Hoek-Brown failure criterion-a1988 update[C]// Proceedings of the 15th Canadian Rock Mech. Symp. Toronto：University of Toronto Press，1988：31-38. " target="_blank">
[21]	戴国亮，龚维明，陈隆. Hoek-Brown 准则的多项式近似解法[J]. 地下空间与工程学报，2012，8(5)：928-932.(DAI Guoliang，GONG Weiming，CHEN Long. Approximate solution of Hoek-Brown criterion using polynomial equation[J]. Chinese Journal of Underground Space and Engineering，2012，8(5)：928-932.(in Chinese)) " target="_blank">
[22]	HONGSEOB O H，JONGSUNG S. Punching shear strength of strengthened deck panels with externally bonded plates[J]. Composites Part B：Engineering，2004，35(4)：313-321.
[23]	中华人民共和国国家标准编写组. GB50007—2011建筑地基基础设计规范[S]. 北京：中国建筑工业出版社，2011.(The National Standards Compilation Group of People?s Republic of China. GB50007—2011 Code for design of building foundation[S]. Beijing：China Architecture and Building Press，2011.(in Chinese)) " target="_blank">
[24]	RATHIE R N，SILVA P D. Applications of Lambert W function[J]. International Journal of Applied Mathematics and Statistics，2011，23(D11)：1-15. " target="_blank">
[25]	刘佑荣. 岩体力学[M]. 武汉：中国地质大学版社，2002：102-108.(LIU Yourong. Rock mechanics[M]. Wuhan：China University of Geosciences Press，2002：102-108.(in Chinese)) " target="_blank">