复合式土压平衡盾构机刀盘对复合地层的适应性决定了施工的安全性和经济性。由于刀盘结构的多样性以及施工环境的复杂多变性,不同类型的刀盘在应对不同地层时,其综合性能表现不一,目前仍缺少对其综合性能进行评价的有效方法。在考虑刀盘性能影响因素多层次、多方面和相关联性的基础上,从刀盘的结构性能、刀具布置性能、力学性能、经济性、安全可靠性和环境适应性等方面,建立刀盘性能评价指标体系。根据刀盘递阶层次结构评价模型特点,提出一种基于模糊数学与评价理论,以模糊层次分析法计算刀盘指标权重,通过模糊综合评价和模糊优劣解距离决策法对刀盘进行综合性能评价的方法。结合长沙某地铁施工标段地质条件,选取四种常见的复合式土压平衡盾构机刀盘方案,进行评价确定最终方案,并通过工程实例验证本方法的合理性和有效性,为施工过程中的刀盘方案选型决策提供一种新方法。
The adaptability of composite earth pressure balanced(EPB) shield machine cutter head to the complex formation determines the security and economical efficiency of construction. Due to the structural diversity of cutter head and the complicated geological conditions of construction, the comprehensive performance for different types is different when they act on different formations. And no suitable and effective method for performance evaluation of cutter head has yet been found. To improve that, with multi-level and multi-faceted and relevance between influencing factors for cutter head performance, an index system cutter head performance assessment is established from the aspects of structural performance, cutter layout performance, mechanical properties, economy, safe reliability and environmental adaptability of cutter head. According to features of the cutter hierarchical structure evaluation model, and based on fuzzy mathematics and evaluation theory, this system proposes a method which uses fuzzy level analytic process to calculate cutter head index weights and adopts fuzzy comprehensive evaluation and fuzzy technique for order preference by similarity to an ideal solution(TOPSIS) decision for comprehensive performance evaluation of cutter head. Also, combining geological conditions of a certain metro bid construction in Changsha, four common programs for composite EPB shield machine are compared, of which the final one is chosen through evaluation of the cutter head performance. The rationality and effectiveness of this method is also verified through engineering examples, thus rendering a new method for the cutter head selection in construction process.