重庆轨道交通工程岩质围岩分级方法研究

围岩分级是地下工程设计、施工的重要基础,在工程建设中发挥了越来越大的作用。调研了国内常用的4部国标、2部行标的围岩分级方法,归纳了不同围岩分级方法的特点与共同点,指出了不同分级方法用于重庆轨道交通工程存在的不足,如分级的工程对象缺乏针对性、定性划分与定量指标不够协调、没有考虑工程因素中跨度的影响。针对重庆地区岩石强度低、完整性好的地质特征,将定性划分与定量指标合理的综合,同时考虑重庆轨道交通建设中区间隧道与车站隧道跨度差异大的工程特点,建议按跨度设置亚级,提出科学合理的围岩分级方法。结合工程实例验证本文分级方法的实用性与先进性,旨在安全的前提下,降低重庆第二轮轨道交通项目的建设费用。

Study on Classification Method of Surrounding Rock for Chongqing Rail Transit Project

Surrounding rock classification is an important basis for underground engineering design and construction,which plays an increasingly important role in engineering construction.The surrounding rock classification methods of 4 common national standards and 2 industrial standards are investigated;the characteristics and common points of different classification methods are summarized and the shortcomings of different classification methods used in Chongqing rail transit project are pointed out,such as lacking pertinence on engineering object of classification,incoordination between qualitative classification and quantitative indexes,not considering the influence of span.According to the geological characteristics of low rock strength and good integrity in Chongqing area,qualitative division and quantitative index are reasonably integrated,meanwhile the engineering characteristics of the span difference between the interval tunnel and the station tunnel in Chongqing rail transit construction are considered.Setting sub-classification by span is recommended.A scientific and reasonable classification method is put forward.The practicability and advance of the classification method are verified by an engineering example in order to reduce the construction cost of Chongqing second round rail transit project under the premise of security.