【作者】 王卓甫；

【导师】 沈祖诒； 杨建基；

【作者基本信息】 河海大学 ， 水利水电工程， 2002， 博士

【摘要】 工程施工进度风险分析计算是施工进度控制中的重要环节。本文用MC(Monte Carlo)方法研究了施工工期的分布规律和PERT(Program Evaluation and Review Technique)网络的时间参数的计算；用概率论的观点定义了PERT网络主导线路和关键度；针对大型施工进度网络MC方法应用的局限性，采用线路合成方法，引进当量概率概念，提出了PERT网络的简化计算方法；根据工程搭接施工网络的特点，将其转化为广义PERT网络，探讨了其施工进度风险的计算。通过本文的研究取得的新成果有：(1)对PERT网络施工工期的分布，即使每一活动持续时间服从正态分布，也不能证明其严格服从正态分布，但当PERT网络线路上的活动较多时，如超过20项，不论活动持续时间服从正态分布、β分布，还是三角分布，当偏态不十分明显时，则工期近似服从正态分布。(2)引进关键度的概念，提出了用MC寻找关键线路的方法。(3)提出了用当量概率修正PERT网络，计算进度风险的方法。采用线路合成，引进当量概率概念，对PERT网络中有二条以上汇入线路节点的最早时间进行修正，并将修正后增加的时间作为一新活动(工序)的持续时间，然后将该新活动作为原节点的紧后工序，而原节点的紧后工序作为该新工序的紧后工序。和MC方法相比，这种修正PERT方法，其有较高的计算精度。(4)提出了搭接施工网络进度风险计算的方法。将施工搭接网络的每一搭接关系改用新增的工序相连，并将该搭接关系的时距定义为这新增工序的持续时间，把这一新工序称为时距工序。时距工序不消耗资源，其持续时间可以是确定的，也可以是不确定的。引入时距工序后，将搭接网络转化为广义PERT网络，然后用MC方法或用当量概率修正PERT方法计算搭接施工网络进度风险。更多还原

【Abstract】 In the control of construction schedule for Hydropower Projects,risk analysis of the schedule is a key. In this paper,Monte Carlo(MC) method is used in the Research of distributing of construction duration and computation of time parameter of PERT network. According to probability viewpoint,critical line and key degree of activity in the network are also defined. Aiming at the limitation of application of the MC in large scale the network,the simplified computational method for the network is presented with quantum probability theory and composite method of path in network. According to the characteristic of precedence network of Hydropower Projects,it is transferred into generalized PERT network,as well the computation of schedule risk is discussed. The achievements achieved in the study are presented as follows:(l)To the distribution of construction duration of the PERT network,even though every activity duration obeys normal distribution,it is failed to be proved to be in the obedience with normal distribution strictly. However,if there -are a lot of activities in a path of the PERT network,for instance,more than 20 activities,without reference to the normal distributions-distribution or triangle distribution which activities duration obeys,the construction duration approximately obeys the normal distribution when the form of distribution is not partiality seriously. (2)After the concept of critical rate is used,critical path is decided with the help of MC.The computational risk of schedule is comparably small with the classical PERT method,but it is effective to decide the critical path-method.(3)With the conception of quantum probability and composite method of path in network,the earliest time of node merged with two or more paths is corrected,and then make a dummy activity which follows the node and which holds a durationtime that the earliest time of the node added time after the paths are merged,and the subsequent work of the node follow the dummy activity. Compared with the MC method,the modified PERT method has comparably computational precision. (4)Substitute the every precedence relation of precedence construction network with a procedure,and the lag of precedence relation is defined as duration of the procedure which is named as lag procedure. The lag procedure does not consume resource,and the duration is random or determined. After the lag procedure introduced,the precedence network is transferred into generalized PERT network,and then the risk of construction schedule could be calculated with the MC method or the modified PERT method.更多还原