【摘要】 锚杆支护在国内深基坑开挖和支护中得到了广泛应用,但对其工作机理和计算方法的研究尚不够完善.以1个预应力锚杆支护的深基坑工程为实例,对工程锚杆进行了试验.通过试验,测试了锚固体在岩土中摩阻力的分布规律及其锚杆中的预应力变化,校验了锚杆的设计数据,为工程提供了设计依据.测试结果表明,锚固体与岩土体间的摩阻力沿锚杆长度不是均匀分布的,其分布规律与摩阻力水平有关,在孔口附近最大,从孔口沿锚杆长度逐渐衰减.锚杆的预应力随着时间变化,其变化与注浆量、锚杆的位置及其锁定荷载有关.锚杆杆体的受力变化对基坑开挖较为敏感,同时围护墙体的水平位移对其有一定的影响.更多还原

【Abstract】 The retaining of anchors is widely used in China,but the principle and calculating method for soil anchor are not so perfect.In this paper,the researches and test on soil anchors is carried out based on a deep excavation.The distribution of the friction force on the interface between soil and mortar and the variation of pretress in anchors are obtained through test.The result shows the distribution of the friction force is not uniform and the stress attenuates along the length of anchor,which is the maximal in the orifice of hole and related to the level of friction force.The pretress in anchor varies in time and is correlative to the grouting amount,location for itself and locking load.The pullout resistance of anchor is sensitive to the excavating for deep excavation,and the displacement of retaining wall is influenced in certain degree when applying prestress on the anchor.更多还原