不同围岩地质条件下盾构掘进效能评价方法

考虑盾构掘进过程中掘进机与围岩的耦合作用,提出反应掘进参数和地质条件综合作用的盾构掘进效能评价指标体系。将岩石磨蚀性指标K_CAI作为围岩可掘性评价指标,构建围岩可破量模型,提出适用于盾构施工的围岩可掘性分级体系。通过对盾构掘进效率研究,提出盾构掘进指数K_STI以反应盾构掘进能耗,基于对盾构施工大数据的分析,确定了不同围岩分级下掘进指数合理区间并进行分级评价。综合围岩可掘性分级和盾构掘进指数分级体系建立盾构掘进效能评价方法,并对盾构掘进效能评价划分为1~7个等级。以广州地铁3号线大石-汉溪区间的地质条件和掘进参数为例,进行了盾构掘进效能评价,验证了该效能评价方法的正确性,为盾构掘进参数的设定提供理论参考依据。

Evaluation Method of Shield Tunneling Efficiency in different Surrounding Rock

Considering the coupling interaction between the tunneling machine and the surrounding rock, this paper puts forward the evaluation index system of shield tunneling efficiency that reflects the combined effect between tunneling parameter and geologies. K_CAI(rock abrasive index)was used to evaluate the surrounding rock’s cuttability, the model of rock-breaking volume and the classification system of surrounding rock cuttability was constructed. Through the studies on the efficiency of shield tunneling, K_STI(shield tunneling index)was proposed to reflect the energy consumption of shield tunneling. Based on the analysis of big data of shield construction, the reasonable interval of shield tunneling index under different rock classification was determined and evaluated. The evaluation method of shield tunneling efficiency was established based on the comprehensive classification of rock cuttability and shield tunneling index, and the evaluation of shield tunneling efficiency was divided into 7 grades. Taking the tunneling machine and the surrounding rock of the Dashi-Hanxi section of Guangzhou Metro Line 3 as an example, the study assets the effectiveness of shield tunneling and verifies the correctness of the method, providing theoretical reference for the setting of the shield tunneling parameters.