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  

Mechanical characteristics of anti-sliding pile considering comprehensive foundation coefficient of sliding bed on composite inclined rock mass

作　　者：董曼曼[1] 王亮清[1] 葛云峰[1] 王聪[1] DONG Man-man WANG Liang-qing GE Yun-feng WANG Cong(Faculty of Engineering, China University of Geosciences, Wuhan, Hubei 430074, Chin)

机构地区：[1]中国地质大学(武汉)工程学院,湖北武汉430074

出　　处：《岩土力学》2017年第10期3000-3008,共9页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.41372310);中国博士后科学基金项目(No.2015M570671)~~

摘　　要：在抗滑桩内力与变形计算中,当前理论分析多将滑床岩体等效成均质体或水平的非均质体,而三峡库区大部分滑床多为复合倾斜岩体。通过3DEC数值试验,研究了抗滑桩的有效影响范围与桩截面宽度、深度的关系,确定了抗滑桩有效影响范围的上、下限;利用面积等效,在桩的有效影响范围内提出了滑床复合倾斜岩体综合地基系数K_(Zi)的公式;推导了基于K_(Zi)的弹性抗滑桩嵌固段受力特征研究的计算公式并编写了MATLAB计算程序。以马家沟滑坡为例,采用等效法、水平层状地基系数法和基于K_(Zi)的计算方法分别进行了抗滑桩嵌固段内力、位移的计算。结果表明,基于K_(Zi)的计算方法与水平层状地基系数法相比,滑面处位移增大14.6%,内力相差较小;同时,基于K_(Zi)的计算方法根据滑动面处的位移反求桩顶的位移与现场监测位移较为接近,而利用传统方法计算位移偏小,设计偏于危险。该方法可为复合倾斜岩体地区的抗滑桩设计提供理论支撑。In the existing theoretical analysis, laminar rock mass of sliding bed is normally equivalent to homogeneous or horizontal non-homogeneous body for calculations of the internal forces and deformation on the anti-sliding pile. However, most of slide beds in Three Gorges reservoir area are composite inclined rock mass. Firstly, numerical simulations using the 3DEC software were conducted to examine the relationships of the effective scope of the anti-sliding pile with the cross-section width and depth of pile. The upper and lower limits of the effective scopes of the pile were determined. Secondly, a formula was developed for the comprehensive foundation coefficient（K_（Zi）） of sliding bed on composite inclined rock mass within the effective scope of pile by the area equivalent. Finally, several formulas of internal forces and displacement considering K_（Zi）, were deduced on the elastic anti-sliding pile. Moreover, correspondingly MATLAB calculation programs were compiled. Taking the Majiagou landslide as an example, the internal forces and displacement of anti-sliding pile under the sliding surface were calculated by the equivalent method, the horizontal layer foundation coefficient method and K_（Zi）-based method, respectively. Comparisons between the K_（Zi）-based method and the horizontal layer foundation coefficient method show that the displacement of sliding surface by the former is greater than that of the latter（14.6%） and the difference of internal force is negligible. According to the displacement of sliding surface, the displacement of pile top calculated by the K_（Zi）-based method is similar with that of field monitoring, while it is smaller by a conventional method and dangerous for design. Thus, the K_（Zi）-based method can provide theoretical support for the area of composite inclined rock mass on the design of anti-sliding piles.

关 键 词：滑床倾斜岩体 抗滑桩 影响范围 综合地基系数 内力与变形 

分 类 号：TU457[建筑科学—岩土工程]