1、翻译部分英文原文Input to the application of the convergence connement method with time-dependent material behaviour of the supportAbstract The convergence connement method is a two-dimensional, analytical method used in the design of sub- surface structures and for the description of ground and system behav
2、iour. Its purpose is to derive the required support measures from the combination of the following values: the ground characteristic curve; a model of the development of the radial deformations of the excavation surface in the axial direction of the tunnel; the support characteristic curve; and the
3、installation time and location of the support measures. The convergence connement method is usually employed in the preliminary design of underground structures. This article investigates the various methods of the convergence connement method and includes comments on possible application scenarios.
4、 One point of focus considers the system-bolting of rock mass as a supporting as well as a reinforcement measure. Another view is taken on the time-dependent material behaviour of shotcrete and its adaptation to the convergence connement method.1.IntroductionUnderground structures can be designed by
5、 using many different calculation methods. While the preliminary design is dominated by analytical and empirical methods, fully modelling the entire construction process in the course of numerical calculations represents the standard procedure for detail design today. Further- more analytical method
6、s can act as a tool for quickly verifying the numerical calculations and assessing the system behaviour during all stages of the design and construction process. Based on that knowledge, the design can be adjusted accordingly. An example for such an analytical procedure is the convergence connement
7、method (CCM).A major development of the CCM was done by Pacher (1964). He investigated the deformation behaviour in an experimental tunnel to describe the ground behaviour.Feder and Arwanitakis (1976) improved the convergence connement method by implementing a linear elasticideal plastic material be
8、haviour into the ground characteristic curve. Further- more, a very important achievement is, that in this case the circular opening and the central symmetrical homogenous stress state is not a requirement for the analytical solution. Most of those solutions use the MohrCoulomb failure criterion. In
9、 1992Carranza-Torres and Fairhurst (Carranza-Torres, 2004; Carranza- Torres and Fairhurst, 2000) developed an application to use an elasticperfectly plastic rock masses with HoekBrown failure criterion.In the last view years the convergence connement method experienced a revival. Newer publications
10、such as (Alejano et al.,2010) from Alejano, describe the implementation of HoekBrown strain-softening behaviour into the convergence connement method.An important part of the CCM is the support characteristic curve. It describes the strainstress relationship of the support measures against the rock
11、mass. For the application of the CCM in real projects, AFTES (Panet et al., 2001) from 2001 can be seen as a fundamental work. A major improvement for the calculation of shotcrete lining and the time dependent behaviour was developed by Oreste (2003). This paper gives also an overview of the possibi
12、lities which the convergence connement method has to offer. 2. Basics2.1. Assumptions and preconditions Determining the ground characteristic curve requires an analytical solution, which usually makes use of the theory of an innite plate with a circular hole. For the analytical solution the followin
13、g assumptions are made: the theory of an innite plate is a 2D model with plane strain conditions and innite dimension,circular opening, central symmetrical homogenous stress state (hydrostatic stress), constant primary stress, homogenous material properties of the rock mass, non rheological material
14、 behaviour, isotropic material law. Only few models partially differ from these assumptions, like for example the one delivered by Feder and Arwanitakis (1976), who with limitations provides geometry for any state of pri- mary stress and oval cavity in his calculations. Most of the assump- tions sta
15、ted above are only met to a certain extent in reality. To be precise, different ground characteristic curves and different sup- port characteristic curve would have to be determined for each point on the excavation surface; in addition, construction se- quences cannot be factored out in the calculat
16、ion, and can only be considered as a simplication.2.2. Stress distribution The stress distribution around a cavity in an elastic medium has been determined by Lame and Kirsch. If, however, the circumferen- tial stresses at the excavation surface exceed the rock mass strength, then a zone with plastic mater
