淺埋破碎巖層隧道小導管預支護技術研究.pdf

1、西安科技大學碩士學位論文淺埋破碎巖層隧道小導管預支護技術研究姓名：范永慧申請學位級別：碩士專業(yè)：橋梁與隧道工程指導教師：戴俊2011-05Subject :Study on the Small Duct Pre-Supporting Technology of Tunnel in the Shallow Broken Rock Sections Specialty : Bridge and Tunnel Engineering Na

2、me : Fan Yonghui (Signature) Instructor : Dai jun (Signature) ABSTRACT When tunneling in shallow broken rock sections, in order to overcome the dis

3、advantageous impact of unstable strata, supportive measures are often taken prior to excavation in the front of the working face to ensure the stability of surrounding rock. This thesis summarizes previous works and cond

4、ucts in-depth study on technology of mall duct pre-supporting. The main research contents and achievements are as follows. (1)It describes the characteristics of surrounding rock under shallow broken geological condition

5、s and points out that the shear strength of broken rock is mostly determined by weak structural plane or weak intercalation; (2)It analyses the reinforcement mechanism and action effect of small duct pre-supporting and d

6、emonstrates that pre-supporting helps improve the stress state of the surrounding rock in front of the working face and increases the stability of surrounding rock. The interrelationship among various pre-supporting unit

7、s can be clarified by building the serial parallel connection model of small duct pre-supporting system. Only when each unit matches in the optimum can the overall system work the best; (3)It explores the tunnel pre-supp

8、orting principle in depth and points out that the pre-supporting force is composed of the self-bearing capacity of surrounding rock and the bearing capacity of supporting structures. As the bearing force of the tunnel Su

9、rrounding Rock and Supporting structure, pre-supporting force, in order to ensure stable surrounding rock in tunnel, is always supposed to be greater than the initial internal force that maintains stable rock masses befo

10、re construction; (4)By comparing the impact on vertical displacement of vault under different working conditions, it illustrates that small duct grouting support plays an important role in controlling vault settlement an