Intelligent back analysis of displacements using precedent type analysis for tunneling

Abstract Based on comprehensive monitored data obtained from typical tunnel projects, and by using engineering experiences of experts together with numerical modeling results, the precedent type analysis (PTA) technique developed was for back-analyzing in situ stress and elastic modulus of rock masses surrounding tunnels. Then, the PTA is used as a supporting technique in the method of intelligent back analysis (IBA). The IBA method can integrate the mechanism analysis with experimental identification. Such integration is based on ‘certainty factors’, and is implemented with the computer program BMP90 with a global inference engine. The program BMP90 can solve a series of back analysis problems—such as identifying potential problems to be encountered during back analysis, assessing the strategy to be adopted, selecting criteria for back analysis, and ensuring convergence of back analysis results. Based on the engineering applications to approximately 100 tunnel projects in China, it is found that the IBA method supported by the PTA technique can be successfully applied to tunnel projects, i.e. back-analyzing the lateral in situ stress factor (λ), and the elastic modulus ( E ) of rock masses. The method of IBA supported by PTA and its application to a tunnel project are presented in this paper.

[1]  Giancarlo Gioda,et al.  Back analysis of the measurements performed during the excavation of a shallow tunnel in sand , 1999 .

[2]  L. Jurina,et al.  On model identification problems in rock mechanics , 1977 .

[3]  John A. Hudson,et al.  ROCK ENGINEERING SYSTEMS. THEORY AND PRACTICE , 1992 .

[4]  N. K. Samadhiya,et al.  Rock mass strength parameters mobilised in tunnels , 1997 .

[5]  R. D. Lama,et al.  Using back analysis to estimate geotechnical field parameters for the design of support systems for tunnels , 1992 .

[6]  John A. Hudson,et al.  Computerization of Rock Engineering Systems Using Neural Networks with an Expert System , 1998 .

[7]  Qinxi Dong,et al.  Back analysis of large geotechnical models , 1999 .

[8]  G. Swoboda,et al.  Developments and applications of the numerical analysis of tunnels in continuous media , 1999 .

[9]  K. Takeuchi,et al.  Back analysis of measured displacements of tunnels , 1983 .

[10]  C. Derek Martin,et al.  The role of convergence measurements in characterizing a rock mass , 1996 .

[11]  R. L. Sterling,et al.  IDENTIFYING PROBABLE FAILURE MODES FOR UNDERGROUND OPENINGS USING A NEURAL NETWORK , 1992 .

[12]  Ma Fengshan,et al.  Application of precedent type analysis (PTA) in the construction of Ertan hydro-electric station, China , 1998 .

[13]  S. Sakurai,et al.  LESSONS LEARNED FROM FIELD MEASUREMENTS IN TUNNELLING , 1997 .

[14]  Giancarlo Gioda,et al.  Numerical identification of soil‐structure interaction pressures , 1981 .

[15]  J. Zhao,et al.  Construction and utilization of rock caverns in Singapore Part C: Planning and location selection , 1996 .

[16]  Yingxin Zhou,et al.  Rock dynamics research related to cavern development for Ammunition storage , 1999 .

[17]  Wang Sijing,et al.  Three-dimensional back-analysis of displacements in exploration adits - Principles and application , 2000 .

[18]  Daniele Peila,et al.  Stability analysis of a large cavern in Italy for quarrying exploitation of a pink marble , 2000 .

[19]  F. Zausa,et al.  Wellbore stability analysis made easy and practical , 1996 .