基于IFS-动态加权的地下综合体深基坑施工风险评价

Risk assessment for the deep foundation pit construction of the underground complex based on the IFS-dynamic weighting

为控制地下综合体深基坑施工风险,提出了一种基于直觉模糊集(IFS)-动态加权的风险评价方法。从地质条件、建筑环境、岩土设计、施工方案和偶然风险5个方面分析地下综合体深基坑施工风险因素,构建了综合风险评价指标体系。采取施工风险5级划分方法,利用IFS理论确定指标风险;以偏大型正态加权函数确定指标权重,得到系统综合风险。以西安市某地下综合体深基坑施工实际为背景,进行方法应用。结果表明,该西安市地下综合体深基坑施工系统风险等级为显著风险。其中,指标“邻近建筑”“地下管网”的风险等级为高度风险,“道路交通”“基坑边坡稳定性”“降排水实施”为显著风险,对此提出了相应的安全措施。

This paper intends to present a risk evaluation method based on the intuitionistic fuzzy set( IFS)-dynamic weighting approach to the construction risk control of the deep foundation pits of the underground complexes. To achieve the purpose, we would like to analyze the construction risk factors of such deep foundation pits and the comprehensive risk evaluation index system consisting of 5 aspects,that is,the geological conditions,the building environment,the geotechnical design,the construction plan and the accidental risk. And,secondly,we would like to determine the index risks to quantitatively describe the degree of ambiguity when decision makers make judgments by using the IFS,for it can help to make up for the shortcomings of the traditional subjective evaluation methods due to its lack of indefinite description of the decision-makers. And,thirdly,the paper has also proposed to adopt a 5-level division of construction risks to determine the index risk and the comprehensive risk of the deep foundation pit construction of the underground complexes based on the relevant domestic standards. And,fourthly,to highlight the difference between the qualitative and the quantitative changes of the indexes so as to describe the trend of the index weight with the growth of the index risks,in which the weight of the index tends to increase slowly with the increase of the index risk at the beginning,and,then,it may lead to fast growth,which tends in turn to get flat in the end with a large dynamic weighting function introduced. And,finally,the comprehensive risk of the deep foundation pit construction of the underground complexes can be accumulated. Thus,it can be seen that the method the paper has proposed can be applied to an actual construction case of the deep foundation pit of an underground complex in Xi’an.And,eventually,the results can be said inclined to reveal that its comprehensive risk level should be of great significance for rectification and control of the measures needed. Among the said indexes,the risk levels of the“adjacent buildings”and“the underground pipe network”should be relegated to be those of high levels. And,meanwhile,“the road traffic”,“the slope stability of the foundation pits ”,and “the drainage implementation ”should also be relegated to the protruded ones. Based on the above 5 high-grade indexation of the risks,the paper would like to propose the corresponding safety measures for the given actual project.