Research Of Network Planning Technique In Mine Construction

Coal resources have not only played a decisive role in the proportion of China’s energy structure, but also stayed the dominant position that will not be changed fundamentally in a short period of time. This makes the demand of mine construction increase continually. Since mine construction has the feature of large investment, long cycle, numerous unknown factors and high risk, it restricts, to a large extent, the investment returns of coal mine construction. Mine construction is a complex engineering that involves multiple departments, types and devices. Therefore, that how to make efficiently use of modern network planning technique, to make the program schedule scientifically and control and optimize of it has a very important significance to improve the benefits of the investment of the mine infrastructure.The massive project practice experience of developed countries shows that network planning technique as a kind of scientific method of organizing producing and managing the plan plays an important role in coordinating the relationship of the departments, planning, optimization, monitoring and reasonable allocation of resources. Coal mine construction as a project of a class of urgency and timeliness, its overall goal is to achieve the control of project schedule, project quality and project investment. Among these, mine construction schedule is the key factor to affect the benefit of the investment of coal mine construction.This paper will focus on a core issue about the construction period in the mine construction project. Using modern technology and methods of network planning, the paper mainly research on the two specific problems that are the optimization of the project schedule and monitoring in the process of coal mine construction project. This paper realizes the optimization of time schedule by in-depth studying on drawing method and algorithm of activity-on-node network which is based on abstract and activity-on-arrow network which is based on time scale and abstract, and combined with the critical path method. Based on the optimization of schedule, aiming at the key activities and the non-critical activities in the process of construction, the paper gives the flow and method of plan monitoring separately, which provides scientific basis and guarantee for the timely adjustment and the successful implementation of plans.The main research work and achievements of this paper are as follows: (1) According to the characteristics of coal mine construction project, such as large quantity of unit project and many chain works, this paper proposes a method of drawing activity-on-node network by adding abstract nodes and calculating the critical path, and gives the specific drawing flow and algorithm in detail. Due to the introduction of abstract nodes, the network diagram compared with the traditional activity-on-node can fully show the hierarchical relationships among each unit project, on the other hand, it can also reduce the complexity of reading network diagram by folding and expanding the scope activities when unit project is numerous. Meanwhile, through calculating the time parameters of activities, the critical activities clearly, the critical lines and total construction time are showed clearly in the network diagram. Thus, we can quickly achieve appraisal, adjustment and optimization of the plan.(2) Activity-on-arrow in use, in order to express the logic relationships between activities sometimes, need to add the dummy activities. But different adding methods may lead to cause more than one possible implementation. To solve the above problems, this paper proposes an algorithm of drawing activity-on-arrow which is based on the time scale and the abstract and a method of calculating the critical path, and gives the specific drawing flow and algorithm. The network diagram compared with the traditional activity-on-arrow network can guarantee that only the dummy activities and suspend activities will exist crossover with other activities, while other activities not, thus, the whole network diagram looks clean and tidy. Meanwhile, through calculating the time parameters of network diagram, the method of generating activity-on-arrow network identifies the critical path with red lines and calculates the total construction time, so as to realize the optimization of the schedule plan.(3) As the practical process of coal mine construction would be affected by various unknown factors, they will come to deviation. Through the study of numerously relevant information, this paper put forward a dynamic control method for the progress of the critical activities and the non-critical activities in the construction, and gives the specific flow of monitoring plan and method. The method can timely monitor the lag tasks and judge the effect degree of the days of tasks delay on the whole project. At the same time the method divides the whole project into three categories in order to monitor specifically and identifies declinational tasks with the eye-catching colors. The above method provides not only the scientific basis for the timely adjustment of the plan, but also the guarantee for the realization of the expectant target.