Experimental Study On Prestress Loss Of Anchor Cables Based On High Filled Foundation

With the advantages of deep initiative support, simple operation and low cost,the prestressing anchors are widely used in slope reinforcement structure. However, due to the theory study of anchor cables’prestressing loss in filled slope is relatively insufficient, the design is mainly based on subjective experience, which often causes invalidation because of the loss of prestress. It greatly limits the engineering application of prestressing anchor cables.In this paper, I regard prestressing loss for the main line of this study, through the model test in laboratory,analysis the law of prestressing loss in filled slope reinforcement with anchor cable-pile wall. Simultaneously connecting with the anchor axial force monitoring datas of high filled slope in Yunnan province, summarize the prestressing loss influencing factors, and propose corresponding engineering control measures, which has a certain reference significance for the anchor reinforcement structure in similar filled slopes. In this paper, the research content mainly includes the following five parts.1. Introduce the research progress about high filled slope and the prestressing loss of anchor cables both at home and abroad, which mainly include the reinforcement measures, subsidence deformation and stability of high filled slope; the test, theoretical calculation formulas, engineering experience calculating formulas of prestressing loss of anchor cable etc. Meanwhile determine the research content and the technical route for this paper.2. Analyze prestressing loss of anchor cables in filled slopes in accordance with the order of construction, which includes prestress tensile loss, locking loss, prestressing losses of anchor cables after locking. Meantime analyze the affection to the prestress loss of environmental factors, construction factors, and summarize prestressing loss formulas of engineering experience in the various stages.3. Establish model test in filled slope of red clay to study prestressing loss of anchor cables in laboratory. As the following:1) Study anchor prestressing loss of tension, locking loss, prestressing loss after locking; 2) study the secondary tension, gravity compaction, grading Heaping and long-term effects, the prestressing anchors variation; 3) regard the length of anchors’free segment as study variables, study the changing regulation of prestressing force in three kinds of free segment levels (45cm, 50cm,55cm), and analyze the influence of the length of the anchor cable on the prestress change of the anchor cable; 4) With 15 cm/layer,5 cm/layer gravity compaction, study on the effect of compaction strength influence on prestressing loss of anchor in filled slope.4. Introduce the engineering situation, support scheme of prestressing anchors and monitoring scheme of high filled slope, through the anchor cable prestress monitoring data, analysis of high fill slope anchor cable prestress changes, and make analysis on prestress changing trend.5. Through the analysis of anchor cables’ prestressing loss monitoring results of high filled slope anchors in Yunnan province and the model test in laboratory, summarize the law of prestress changes in filled slope and put forward engineering measures to control prestressing loss of cables in high filled slope reinforcement with anchor cable-pile wall.