EPB Composite Shield Cutter Tool To Optimize The Allocation Of Research

With the development of the national economy and the rising demand for the engineering construction, shield machine has been widely used in underground engineer constructions, such as construction of tunnel and orbit traffic. Cutter-head is an important component of shield machine and it plays a major role to break rock and support the tunneling interface. The reasonable disposition of the cutters is the basic guarantee for the machine to tunnel efficiently and stably, and also an important measure to reduce vibration of the cutter-head, balance the force of the cutter, reduce the tunneling energy consumption, and extend the life of the cutter-head. Based on substantial literature and integration of theories with project practice, this paper focuses on the type selection of cutters, key factors analysis of cutter arrangement and the optimization of it. The main contents of this paper can be summarized as follows:1. The method of selecting cutters type based on fuzzy theory is proposed. First, the membership function of the compressive strength and the integrity of the rock are set up, and then the single-factor evaluation is carried on according to fuzzy rules established. Finally, the comprehensive evaluation is executed based on fuzzy comprehensive evaluation model in order to select the cutter type adapted to the strata.2. The two key factors such as cut spacing and cutter phase involved in cutter arrangement are analyzed. First, the method of calculating the volume of broken rock is deduced in theoretic, and it leads to the proposal of the methods to determine cut spacing based on the minimum energy consumption. And then, a disc cutter cutting experiment is conducted and the trend of energy consumption changing with cut spacing is verified. Finally, the cutter arrangement of a cutter-head has been improved in simulation application, and the role of cutter phase angle in balancing load of the cutter-head is analyzed.3. The adaptability of three typical cutter-head structures to geological conditions is analyzed, and some similarities and differences in load of the cutter-head with different forms are obtained. According to the requirements both in the mechanical transmission characteristics and geological adaptability of the cutter-head, it is pointed out that the bracket, the joint of spokes and ribs, as well as the opening ratio of cutter-head should be taken into serious consideration when the shield cutter-head is designed.4. Genetic algorithm is used here in order to optimize disc-cutter arrangement. The tings such as the minimum of the cutter-head's radial unbalanced force, the minimum of the cutter-head's overturning moment and the minimum difference of rock breaking amount are selected as the optimization objectives. The optimization model of cutter arrangement with constraint is established. The fitness function of the problem is established by using linear weighting method and penalty function method, and then it is encoded with the real numbers. It is accounted with matlab genetic algorithm and optimal parameters are gained.