三处滑坡工后锚索承载性能现场试验对比分析

The Contrastive Analysis of Anchor Bearing Performance of Three Landslides

工后边(滑)坡预应力锚固工程的长期工作性能是影响锚固工程安全性的一个关键问题。通过一种改进的拉拔检测设备,对重庆三处滑坡工后锚索结构进行了锚索抗拔力检测。通过对各工点检测结果的分析,对各工点锚索结构物当前预应力状态,预应力损失率,锚索安全储备进行了科学判定,为补强整治提供依据。对比分析了造成三处滑坡预应力损失差别较大的原因,岩体蠕变变形及锚索的松弛耦合变形是导致工后锚索预应力损失的主要原因,对于过于松散破碎或含水量较大的滑坡体尽量避免采用预应力锚索结构。通过对比分析各工点工后锚固工程的应力状态及锚索破坏方式表明,锚固段破坏是引起锚固工程失效的主要方式之一,今后锚索工程施工时,应重点注意锚索的长度及注浆等施工质量。对于大型的边(滑)坡中的预应力锚固工程建议安装锚索测力设备,以便时掌握预应力损失情况,及时进行补张拉,防患于未然;对于未安装锚索测力设备的,建议封锚时,预留钢绞线长度大于5 cm,以便工后进行拉拔检测试验。此种改进的拉拔检测设备具有简单、实用、易操作等特点,值得在工后岩土锚固工程长期性能评价领域推广应用。

The long-term performance of prestressed anchoring engineering is the key problem that affecting the anchoring construction safety.To detection of the anchor rope pulling force through an improved drawing testing equipment.To make the scientific decision by the anchor cable prestress value,the prestressed loss and anchor rope safety reserve,it provides the basis of reinforcement renovation.To analyzed the causes of stress loss distinction between each worksite,the rock mass creep and loose coupling deformation of anchor cable is the main reason that caused prestress loss after work,to avoid using prestressed anchor cable structure for larger too loose and broken or moisture content of landslides.Through the analysis of the anchoring construction worksite after stress state and anchor cable failure mode shows that the anchoring damage is one of the main methods of failure caused by anchoring engineering,anchor cable engineering construction in the future,should focus on the length of anchor cable,grouting construction quality,etc.For large prestressed anchorage engineering of side slope（ slip） suggest installation of anchor cable force measurement equipment,in order to grasp the prestress losses,in a timely manner for tensioning,nip in the bud; for not installed cable force measurement equipment,it is recommended that the sealing anchor,steel strand length is more than 5 cm,reserved for drawing test experiment was carried out after work.This paper introduces the drawing of this improved detection device has the characteristics of simple,practical and easy to operate,is worth in the field of rock and earth anchoring construction after long-term performance evaluation.