斜坡地基中基础抗拔承载特性的试验研究

发布时间：2018-06-12 18:30

本文选题：黄土 + 架空输电线路　；参考：《地下空间与工程学报》2016年S2期

【摘要】：斜坡地基中杆塔基础抗拔承载特性是目前输电线路工程中亟待解决的关键技术难题之一,而目前的相关成果仅停留在理论分析中,并无试验数据支撑。本文以输电线路中常用的掏挖基础为研究对象,在20#斜坡地基中开展了直柱、扩底两种结构型式的全尺寸基础上拔静载试验,获得试验基础荷载位移曲线、地基土压力、地表土体裂缝等数据,对比分析了两种型式的基础在变形特征、破坏模式、抗拔承载力构成等方面的差异。结果表明:直柱基础荷载位移曲线呈陡降型,扩底基础呈缓变型,且扩底基础抗拔承载力是直柱基础的2.5倍;沿坡向两侧土体在变形和破坏特征方面均存在差异,这种差异是由两侧土体有效抗拔深度不同所致;基础抗拔承载力的三个组成部分基础自重、扩大头处土抗力(直柱基础这部分为0)、基柱侧摩阻力在加载过程中发挥程度存在明显的阶段性差异。
[Abstract]:The uplift bearing characteristic of tower foundation in slope foundation is one of the key technical problems to be solved urgently in the transmission line engineering at present, but the related achievements only remain in the theoretical analysis, and there is no experimental data to support it. In this paper, taking the excavated foundation commonly used in transmission lines as the research object, the static load test is carried out on the full scale foundation of two types of straight columns and reamed foundations in the 20 # slope foundation. The load-displacement curve of the test foundation and the soil pressure of the foundation are obtained, and the load displacement curve of the test foundation and the soil pressure of the foundation are obtained. The differences of deformation characteristics, failure modes, and the composition of uplift bearing capacity between the two types of foundation are compared and analyzed. The results show that the load-displacement curve of the straight column foundation is steeply reduced, the base foundation is slowly modified, and the uplift bearing capacity of the expanded foundation is 2.5 times that of the straight column foundation, and the deformation and failure characteristics of the soil on both sides along the slope are different. The difference is caused by the difference of the effective pullout depth of soil on both sides, and the weight of the foundation of the three components of the uplift bearing capacity of the foundation. Expanding the soil resistance at the head (the part of the straight column foundation is 0), there is obvious stage difference in the exertion degree of the frictional resistance on the side of the foundation column during the loading process.
【作者单位】：中国电力科学研究院;
【基金】：国家电网公司科技项目(GCB17201400162)
【分类号】：TU476

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