浅层平板载荷试验变形模量计算公式推导  

Derivation of calculation formula for deformation modulus of shallow plate load test

作　　者：刘秀军 LIU Xiu-jun(Shenzhen Geotechnical Investigation&Surveying Institute(Group)Co.,Ltd.,Shenzhen 518028,Guangdong,China;State Key Laboratory for Geomechanics and Deep Underground Engineering,China University of Mining and Technology,Xuzhou 221116,Jiangsu,China)

机构地区：[1]深圳市勘察测绘院(集团)有限公司,广东深圳518028 [2]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221116

出　　处：《地基处理》2022年第6期459-465,共7页Journal of Ground Improvement

摘　　要：岩土的变形模量是岩土工程计算分析中的一个重要的力学参数,目前主要通过原位平板载荷试验的结果计算求得。国内相关规范和文献虽然提供了浅层平板载荷试验中变形模量的计算公式,但并未给出其出处,因此有必要对其进行系统的研究。本文基于Boussinesq弹性理论位移解,对浅层平板载荷试验计算变形模量的公式以及刚性承压板的形状系数进行了系统的推导和阐述,并得出以下结论:(1)变形模量的计算公式是在Boussinesq弹性理论竖向位移解的基础上乘了一个刚性承压板形状系数得来;(2)圆形垂直均布荷载作用下,圆心处的表面沉降为荷载圆边界处表面沉降的π/2倍;(3)正方形垂直均布荷载作用下,正方形荷载中心处的表面沉降为角点处表面沉降的2倍,荷载边界中心处的表面沉降约为角点处表面沉降的1.79倍;(4)推导出的圆形刚性承压板形状系数约为0.818,方形刚性承压板形状系数约为0.935,均略大于相关规范提供的数值。本文系统地解答了浅层平板载荷试验中变形模量计算公式的来源问题,对全面了解此类问题有一定指导和借鉴意义。The deformation modulus of rock and soil is an important mechanical parameter in the calculation and analysis of geotechnical engineering. At present, it is mainly calculated using the results of in-situ plate load test. Although the relevant domestic specifications and literatures provide the calculation formula of the deformation modulus in the shallow plate load test, they do not cite the resources. So it is necessary to study it systematically. Based on the displacement solution of Boussinesq elastic theory, this paper systematically deduces and expounds the formula for calculating the deformation modulus of the shallow plate load test and the shape coefficient of the rigid bearing plate, and draws the following conclusions.(1) The calculation formula of deformation modulus is obtained by multiplying the shape coefficient of a rigid bearing plate on the basis of the vertical displacement solution of Boussinesq elastic theory.(2)Under the action of circular vertical uniform load, the surface settlement at the center of the circle is π/2 times the surface settlement at the boundary of the load circle.(3) Under the action of a square vertical uniform load, the surface settlement at the center of the square load is twice that at the corner point, and the surface settlement at the center of the load boundary is about 1.79 times the surface settlement at the corner point.(4) The shape factor of the deduced round rigid bearing plate is about 0.818, and the shape factor of the square rigid bearing plate is about 0.935, which are slightly larger than the values provided by the relevant specifications. This paper systematically answers the question of the source of the calculation formula of the deformation modulus in the shallow plate load test, which has certain guidance and reference significance for a comprehensive understanding of such problems.

关 键 词：Boussinesq弹性理论 位移解 平板载荷试验 变形模量 刚性承压板 形状系数 

分 类 号：TU413.4[建筑科学—岩土工程]