摘要
针对在地下水作用力使用中易出现力的概念混淆、重复计算等问题,论述了土体中的孔隙水压力、浮力、渗透力3种地下水作用力的性质,从能量守恒角度论证了稳定渗流环境下的孔隙水压力与水深和水力坡角相关;探讨了浮力、渗透力两种体积力与边界孔隙水压力的等效关系,论述了在稳定渗流环境下的土体稳定性计算采用土-水分算与土-水合算两种方法时,前者应使用渗透力和土粒浮重度进行平衡计算;后者应使用孔隙水压力和土体饱和重度进行平衡计算。在此基础上,对现行滑坡防治工程的相关规范中滑坡稳定性计算公式中的地下水作用力的不当使用问题进行了探讨,并采用工程实例对其引起的稳定性计算偏差进行分析。结果显示:相关规范中存在渗流条件下孔隙水压力未考虑水力坡角及孔隙水压力与浮力概念混淆的错误,这两种情况都将造成设计偏保守,工程治理时后者将造成较大的经济浪费。
In order to clarify the concept confusion and to avoid repeated calculation of the force in the groundwater condition, the characteristics of three kinds of groundwater forces in soil, namely pore water pressure and buoyancy and seepage force, are discussed. It is emphasized that the pore water pressure in seepage environment is related to water depth and hydraulic slope according to the energy conservation theory. Then the equivalent relationships for two volume forces(buoyancy and penetration) to the boundary force(pore water pressure) are discussed. The calculation method of groundwater force acting on the separate soil skeleton and the unity of soil skeleton and pore water in a seepage environment is explored. The former should use seepage force and effective gravity of soil particle to calculate equilibrium. The latter should use pore water pressure and saturated gravity of soil to calculate equilibrium. Then the improper use of the groundwater force in present codes for landslide stability analysis related to landslide control engineering is discussed in this paper. In addition, the calculation deviation caused by the improper use of the groundwater force is illustrated in an engineering example. The results show that two problems exist in the relevant specification: pore water pressure is calculated without considering hydraulic slope angle and the concept of pore water pressure and buoyancy are confused. Both cases will cause partial conservative design and engineering management based on the latter case will arise large economic waste.
作者
尹晓萌
晏鄂川
刘旭耀
李兴明
YIN Xiao-meng;YAN E-chuan;LIU Xu-yao;LI Xing-ming(Faculty of Architecture and Civil Engineering,Xinyang Normal University,Xinyang,Henan 464000,China;FacuIty of Engineering,China University of Geosciences,Wuhan,Hubei 430074,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2019年第1期156-164,共9页
Rock and Soil Mechanics
基金
国家重点基础研究发展计划(973)项目(No.2011CB710605)
国家自然科学基金项目(No.41807240)
信阳师范学院"南湖青年学者"奖励计划~~
关键词
土体稳定性
孔隙水压力
渗透力
浮力
设计规范
soil stability
pore water pressure
seepage force
buoyancy
design code
