Study On Performance Evaluation And Reinforcement Method Of Anchorage Slope Engineering During Operation Period

With the vigorous development of infrastructure construction in recent years,many slope projects inevitably emerge in the process of engineering construction due to the complex and diverse topography and geological structure.Prestressed anchorage structure has become the main support measure of slope engineering because of its fast construction,small disturbance to rock and soil,and obvious reinforcement effect.Although slope anchorage technology has been quite mature and many slopes have been effectively harnessed,the working behavior of these slope anchorage structures will change in varying degrees due to the influence of climate and human activities during the operation process for many years.How to objectively and accurately evaluate the working characteristics of these anchorage structures and the stability of anchored slopes during the operation period,and to reinforce them scientifically and effectively,has become very urgent and necessary.Based on this background,this paper firstly studies the disease mode,influencing factors and failure mechanism of slope anchorage engineering in operation period,especially the law of prestress loss of anchorage structure,and establishes the theoretical model of safety evaluation of anchorage structure by using fuzzy analytic hierarchy process.Then,based on the analysis of the influencing factors of slope stability,the evaluation results of anchorage structure are introduced to improve the fuzzy hierarchical evaluation methods of slope anchorage engineering in operation period.Finally,the reinforcement principles and methods are put forward for the disease engineering,and the effects of different tension modes on the long-term performance of anchorage engineering are studied.The main conclusions are as follows:(1)Based on the existing research results of anchorage theory and failure mode,and combined with field investigations and detection data,eight kinds of disease modes of slope anchorage structure in operation period are summarized and put forward.(2)Combining analytic hierarchy process(AHP)with fuzzy theory,a fuzzy hierarchical evaluation model for the safety of slope anchorage structure in operation period is established.The model is applied to an engineering example and objectively and accurately evaluated results are obtained.(3)Based on the analysis of the influencing factors of slope stability,combined with the evaluation results of anchorage structure and the characteristics of anchored slope in operation period,the theory of fuzzy hierarchy evaluation is introduced to improve the evaluation system of slope performance and the model of fuzzy hierarchy evaluation.The model is used to analyze and evaluate an engineering case,which provides a theoretical basis for later reinforcement.(4)The reinforcement principle and methods of anchoring slope disease engineering are put forward,and the effectiveness of the reinforcement methods is verified by engineering examples.Based on the summary of the factors influencing the failure mode of anchorage engineering,the key technical measures during the design,construction and operation of slope anchorage engineering are pointed out.(5)Statistical analysis is made on the measured data of anchor cable prestressing on a highway slope for more than two years,and the law of long-term prestressing changing with time is fitted.Based on the back analysis of the fitting results,the creep parameters of strongly weathered granite are deduced,and the prediction model of long-term prestressing change of anchor cables is obtained,which provides a basis for evaluating the working properties of the rock slope.(6)Through the comparative test of different tensions and locking technology of the pre-stressed anchor cable,it is found that the multi-cycle tension method can eliminate part of the prestress loss caused by creep of rock and soil in advance,and can significantly reduce the long-term prestress loss of the anchor cable structure during its operation period.It is an effective measure to improve the long-term anchorage performance.