基于脆弱性的地下工程穿越施工风险评价与控制

Risk analysis and control based on the vulnerability for the new buildings near the already existing metrotraffic system

为了更加全面、系统地评价新建地下工程穿越既有地铁项目施工的风险,更好地实现风险管控,将脆弱性评价引入地下工程穿越施工风险评价领域,建立了脆弱性评价与风险评价的基本关系,首次提出了基于脆弱性的风险评价方法。该方法在同一维度考虑了工程技术和工程管理等多方面因素,选取暴露度、敏感度和适应度为脆弱性评价三要素,并基于突变级数法基本原理建立了系统脆弱性评价模型,划分了脆弱性等级。以脆弱性等级和外部扰动造成的损失等级为基础,构建了基于脆弱性的风险评价方法,该方法可非常便捷地评价不同实施方案的优劣。通过实际穿越工程案例的应用,验证了该方法的有效性和便捷性。并结合该工程两个不同实施方案的脆弱性和风险计算结果,特别是根据脆弱性评价结果中数值较大的一级和二级指标,快速找出了对应实施方案的薄弱环节,从而优化了工程实施方案,并针对薄弱环节制定了系统风险控制的有效措施。工程实施完成后,既有地铁上浮变形不到1 mm,是该领域变形控制最好的项目之一。同时,地铁运营管理方可利用该方法建立穿越工程风险项目库,实现资源的有效配置和风险的分级管控。

This paper is inclined to make a systematic and comprehensive specific evaluation of the vulnerability assessment of the newly built underground engineering projects across the currently already existing metro-lines. For the said purpose,we have proposed a risk assessment method based on the vulnerability assessment for the first time in terms of dealing with the relation between the risk assessment and that of the vulnerability.The said method actually involves technical and managerial factors in the same dimensions,whereas the model of the vulnerability assessment is concerned about the 3 basic factors,known as the exposure,sensitivity and fitness to be established and classified based on the basic principle of the catastrophe series method. Taking into account the level of the vulnerability and the level of the loss caused by the disturbance from the new construction,we have proposed the risk assessment method,which can help to assess the advantages and disadvantages of the different construction schemes more conveniently and operationally. The application of the said assessment method will enable us to evaluate the two authentic construction scheme projects. Furthermore,analyzing the index results of the vulnerability assessment can also help to find the alternative designing approaches and the supportive measures involved. Particularly speaking,the analysis of the indexes of the first and the second level,which turn out to be of much greater help to discover promptly the weaknesses of each construction scheme,so as to optimize the construction schemes and effective measures in controlling the systemic risks. Thus,what is said above can help to verify the effectiveness and convenience of the aforementioned methods successfully,so that the final deformation of the existing metro in the upward direction in the project can be reduced to or by less than 1 mm by using the said optimized construction schemes,which can be taken as one of the most successful examples in the given area. And,furthermore,the above introduced method has been recommended to the metro operation management companies so as for them to establish a risk project group in building new underground projects to allocate more effective resources and heighten their management efficiency and proficiency.