Drilling Subway Tunnel Wall Stability Test Study

Abstract

Wall stability is key issue is the impact tunneling smooth. Wellbore stability depends mainly on rock strength and in situ stress state. not only the rock strength and rock structure, composition, but also to have a close relationship with the drilling fluid properties. since the subway tunnel excavation is several hundred meters deep underground construction, especially in underground geological formations, mostly rock, pores, cracks multi-media, in the mining process is easy to loose, causing the collapse. to this end we will mature drilling underground mining technology into them, the use of drilling fluid along the cracks into the physical and chemical effects occur with the rock, thereby changing the strength and mechanical properties of rock and rock stress condition. enable improved wellbore stability, thus ensuring the smooth progress of subway excavation work. In this paper, tibet Road shanghai river tunnel formation, for example, through the formation of physical and chemical performance test, the influence of drilling fluid on the wellbore stability [1].