框架预应力锚杆柔性支护结构坡面水平位移的理论分析与模型试验研究  

THEORETICAL ANALYSIS AND MODEL TEST STUDY OF SLOPE HORIZONTAL DISPLACEMENT OF GRILLAGE FLEXIBLE SUPPORTING STRUCTURE WITH PRESTRESSED ANCHORS

作　　者：周勇[1] 朱彦鹏[1] 

机构地区：[1]兰州理工大学土木工程学院,甘肃兰州730050

出　　处：《岩石力学与工程学报》2010年第A02期3820-3829,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(50978129);兰州理工大学博士科研基金项目(BS04200902)

摘　　要：基于基坑开挖过程的影响,视锚杆自由段为弹簧,将开挖阶段的框架预应力锚杆柔性支护结构简化为底端铰接,而上部在不同深度位置处由锚杆弹簧支承的竖向连续梁;提出这种支护结构的坡面水平位移简化计算方法,给出计算模型和计算简图,确定相关参数。以一基坑工程为例,通过对其坡面水平位移的计算分析,分析结果表明,基坑上部位移较大,框架预应力锚杆柔性支护结构在控制基坑水平位移方面效果显著。另外,为深入了解框架预应力锚杆柔性支护结构的工作性能,依据几何相似原理,对其进行室内模型试验研究。位移实测结果与理论计算结果的对比分析表明,二者在总体趋势上吻合较好,但数值上相差较大,试验结果仅仅是定性得出了水平位移的分布规律和预应力锚杆的锚固效果。提出的坡面水平位移计算方法是一种简化近似计算法,各参数容易确定,因此具有可操作性,用于初步估算是可行的。Based on the influence of excavation process,the free segment of anchor is regarded as spring,and the grillage flexible supporting structure with prestressed anchors is simplified as a vertical continuous beam,in which the bottom is regarded as hinge and the upper part is supported by anchor springs located at different positions. Then,a simplified calculating method of the horizontal displacement of slope of this kind of supporting structure is proposed. The calculating model and sketch are given out,and the relative parameters are determined. Taking a foundation pit for example,the calculation results and analysis of the horizontal displacement of slope show that the middle-top horizontal displacements of foundation pit are larger,and grillage flexible supporting structure with prestressed anchors has obvious effect on strictly controlling the horizontal displacement of foundation pit. In addition,in order to deeply understand the working performance of grillage flexible supporting structure with prestressed anchors,the laboratory model test is carried out based on geometric similarity rule. The comparison of the measured results of displacements and the theoretical calculated results indicates that the general trend agrees well,but there are large difference between the two values,and the model test justly obtains the distribution law of horizontal displacement and the anchorage effect of prestressed anchors. The calculation method of the horizontal displacement of slope is a simplified and approximate method,in which all the calculated parameters are easily determined,so the method is operable and feasible in the initial estimation of the horizontal displacement of slope.

关 键 词：土力学 框架预应力锚杆 柔性支护结构 坡面水平位移 理论分析 模型试验 

分 类 号：TU47[建筑科学—结构工程]