水平荷载作用下加翼掏挖基础承载特性研究

The Bearing Capacity Character of Dug Foundation with Plates under Horizontal Loads

基于"m"法,对加翼掏挖基础在水平荷载作用下的承载特性进行力学分析,推导出水平荷载作用下加翼掏挖基础水平位移及基础内力弯矩计算公式;通过对翼板设置位置、翼板尺寸等参数相对基础水平承载力的敏感性分析,提出可使加翼掏挖基础水平承载特性最好的翼板最优设置深度;以某220kV线路工程某塔位加翼掏挖基础为例,分析了翼板设置深度、翼板尺寸对基础顶部水平位移、内力弯矩影响规律,并对基础进行了优化设计。结果表明,基础顶部水平位移随翼板设置深度、翼板尺寸呈非线性变化规律,翼板的设置减小了基础内力弯矩设计值,相同设计条件下,加翼掏挖基础比普通掏挖基础节省工程造价20%左右,经济效益明显。该研究工作不仅对加翼掏挖基础承载机理及翼板设计参数对水平承载力影响规律进行了理论研究,同时提出的翼板优化设计方法可为工程设计人员提供理论支持和技术指导。

Based on the ＂m＂ method,the mechanical analysis is carried out on the horizontal bearing of dug foundation under horizontal loads and the corresponding analytical formulas of foundation horizontal displacement and moment are derived.Through sensitivity analysis of the plate design parameters including layout and scales of the plate,optimal buried depth for the highest horizontal bearing is proposed.Taking a 220kV Transmission Line project as an example,the effect of the buried depth and scales of the plate on the foundation horizontal displacement and moment is discussed.In addition,the optimal design of the dug foundation with plate is also completed.It is shown that a nonlinear relationship can be found between the foundation horizontal displacement and moment and the plate depth and scales.By the engineering cost comparison of dug foundation with plate and dug foundation without plate in the same design condition,the former is 20% lower than the later and good economic benefit will be obtained by applying this design method.The study in this paper provides the important theoretical support on horizontal bearing character and the effect of the depth and scale of plate on foundation horizontal displacement and moment,at the same time,the optimal design method proposed on dug foundation with plate gives the valuable technical guidance to designer.