锚杆(索)及土钉抗拔承载力检测的若干问题探讨

Discussion on the Test of the Pullout Bearing Capacity of Anchor(Cable) and Soil Nailing

目前,涉及锚杆(土钉)抗拔承载力检测的规范众多,且每本规范说法有所不同,常给检测人员带来很大困扰。论文对这些规范进行比较分析,得出以下结论:在锚杆抗拔承载力检测中,基础锚杆最大加载量为锚杆设计荷载的 2 倍;支护工程锚杆在基本试验时,需对最大加载值杆体的极限承载力进行预估,通过试验确定锚杆的极限抗拔承载力;验收试验时,应根据相关规范进行设计,并根据锚杆类型或基坑安全等级确定最大加载量;基础锚杆在基本试验及验收试验中均可采用分级维持荷载法,具体检测方法可参照相关标准执行;支护工程锚杆基本试验优先选用多循环加载法,其次选用单循环加载法;验收试验,可采用单循环加载法。

At present,there are many specifications related to the test of the pullout bearing capacity of bolts (soil nails),and each specification is different,which often brings great trouble to the testers.The paper makes a comparative analysis of these specifications and draws the following conclusions:in the test of bolt pullout bearing capacity,the maximum load of foundation bolt is 2 times of bolt design load;it is necessary to estimate the ultimate bearing capacity of the bolt with the maximum loading value and determine the ultimate tensile bearing capacity of the bolt through the basic test;during the acceptance test,the design should be carried out according to the relevant specifications,and the maximum load should be determined according to the type of anchor or the safety level of foundation pit;grading maintenance load method can be adopted in basic test and acceptance test of foundation bolt;the specific detection method can be implemented according to relevant standards;the multi-cyclic loading method is preferred in the basic test of supporting engineering bolts,followed by the single-cyclic loading method;single cyclic loading method can be used for acceptance test.