铁路隧道软弱围岩大断面机械化施工经济性研究与分析

为分析铁路隧道软弱围岩大断面机械化施工经济性的影响因素，以及各因素的影响程度，依据郑万高铁软弱围岩大断面机械化施工和普通机械化施工（台阶法）2套设计图的工程量，结合现行铁路造价标准与部分软弱围岩大断面机械化配套工艺单价分析，编制3套概算方案从工程量优化和工艺工法变化2个方面进行对比研究。研究结果表明： 1）影响大断面机械化施工经济性的主要因素是超前加固； 2）Ⅳa、Ⅳb、Ⅴa级围岩大断面机械化施工较普通机械化施工延米概算指标分别增长了-9.41%、10.81%和6.24%； 3）Ⅳ、Ⅴ级围岩大断面机械化施工较普通机械化施工月进尺分别提高了9.33%和22.22%，体现出一定的综合经济性。

Economic Analysis on Large Cross sectional Mechanized Construction ofSoft Rock Railway Tunnel

The influencing factors and their influencing degree of economy of large cross sectional mechanized construction of soft rock railway tunnel are of great significance. As a result, the construction quantities of two mechanized construction design drawings, i.e. the large cross sectional mechanized construction and conventional mechanized construction(bench method) of soft rock tunnel of Zhengzhou Wanzhou High speed Railway, are introduced, and three sets of budgeting schemes are established from aspects of quantity optimization and technology variation based on existing railway cost standard and partial unit price analysis on large cross sectional mechanized construction of soft surrounding rock. The research results show that: (1) The advance reinforcement is the main economic affecting factor of large cross sectional mechanized construction. (2) Compared with the conventional mechanized construction method, the budgeting index per meter of large cross sectional mechanized construction in Grade Ⅳa, Ⅳb and Ⅴa surrounding rocks increases by -9.41%, 10.81% and 6.24% respectively; and the monthly advance of large cross sectional mechanized construction in Grade Ⅳ and Ⅴ surrounding rocks increases by 9.33% and 22.22% respectively, which shows obvious economy.