基于组合赋权理想点法的高切坡安全评价

Research on the safety assessment of highcutting slope in the highway construction based on the combination weighting ideal point method

选取高切坡的黏聚力、内摩擦角、高切坡类型、地形坡度、边坡高度作为评价指标,结合理想点法的基本原理,建立高切坡安全评价模型。针对指标权重评价中存在主观影响因素过多、评价指标权值不确定等问题,运用组合赋权法来确定其权重系数,并对实际工程的高切坡进行安全评价。结果表明,所选高切坡的评价结果与实际评价结果基本一致,证明该方法用于高切坡的安全评价合理、有效。

This paper has made a thorough research on the safety assessment of ideal-point high cutting slope. Still,such safety assessment is based on the combination weight. It is a common knowledge that there exists a number of problems in index weight,for example,too much subjective effect and uncertainty of evaluation on the index weight and so on. Seeing the above situations,we have adopted the improved combination weight method in combination with the united DEPHI method and entropy evaluation method so as to give consideration to preference for properties,trying best to reduce the arbitrariness out of subjectivity and thus to achieve the unity of subjective and objective weight on properties. We have also selected a few evaluation indexes,that is,the high-cutting slope＇s cohesion,angle of internal friction,types of high cutting slope,topographic gradient and height of the side slopes. We have determined the weight coefficients of the above-mentioned evaluation indexes by combination weight method and adopted the DEPHI method for calculating the subjective weight,with the entropy evaluation method used to calculate the objective weights.And then,in accordance with the tendency of decision makers,the final weights can be determined through the comprehensive application of the above two methods. Still,based on the basic principles of the ideal point method,the ideal point and the anti-ideal point matrix can be resorted to the calculation of the close degree of the ideal points. The closer the optimal solution to the indexes moves towards the positive ideal point,the farther it departs from the negative ideal point,and the better the solution we can arrive at from the calculation. And,finally,we have managed to establish a model for the safety assessment of high cutting slope through the model test by using the data as measured in the high cutting slope of Liangwu Road in Chongqing City. The results show that the combination weight and ideal point method proves to work well in the case here. What is more,the evaluation result of the selected high cutting slope agrees with the real evaluation result basically,which is verified reliable and effective to use the ideal point method in the safety assessment of high cutting slope.