دانلود رایگان مقاله لاتین مدلسازی فیزیکی تونل ها در زمین نرم از سایت الزویر
عنوان فارسی مقاله:
مدل سازی فیزیکی تونل ها در زمین نرم: نقد و بررسی
عنوان انگلیسی مقاله:
Physical modeling of tunnels in soft ground: A review
سال انتشار : 2015
برای دانلود رایگان مقاله مدلسازی فیزیکی تونل ها در زمین نرم اینجا کلیک نمایید.
بخشی از مقاله انگلیسی:
3. Tunnel modeling techniques
Several modeling approaches have been developed to investigate different aspects of ground response to tunneling. The tested soils are typically contained within an apparatus with rigid boundaries. The container is usually lubricated to limit the frictional resistance imposed on the soil. Often at least one of the faces is transparent to enable researchers to visually record the soil movements. A summary of selected physical modeling techniques used in tunneling research is provided below. 3.1. Trap door models The problem of ground pressure against buried structures has been of great practical importance in civil engineering. Terzaghi (1936, 1943) explained the arching theory based on the translation of a trap door into the soil (passive mode) or away from it (active mode) as shown in Fig. 1. The passive mode can be used to evaluate of the uplift force of anchors and other buried structures that can be idealized as anchors. The active mode can be used to study the silo problem or the earth pressure on a tunnel lining. Following from Terzaghi’s work several researchers conducted 1g trapdoor tests using either aluminum rods (e.g. Ladanyi and Hoyaux, 1969) or dry sand (e.g. Vardoulakis et al., 1981) to simulate the response of granular materials to trap door displacement under plane strain conditions. Typical failure patterns for the active and passive modes of trap door displacements are shown in Fig. 2. In tunneling applications, trap door models are considered to be an approximate method to simulate ground response to tunneling. They facilitate the evaluation of the surface settlement and the corresponding earth pressure on a tunnel lining. To demonstrate the application of the trap door method in tunneling research, two experimental examples along with some testing results are given below. 3.1.1. Two-dimensional tests 2D trap door tests were conducted by several researchers (e.g. Terzaghi, 1936; Vardoulakis et al., 1981; Tanaka and Sakai, 1993; etc.). Park et al. (1999) conducted a series of 1g trap door experiments to investigate the response of inclined layers to tunnel excavations. The tested material consisting of aluminum rods (unit weight = 21.1 kN/m3 and friction angle = 30) and aluminum blocks (unit weight = 26.4 kN/m3 and friction angle = 20) was arranged in layers making angles, h1, of 30, 60, and 90with the horizontal. The setup (shown in Fig. 3) composed of 40 supporting blocks, 2.45 cm in width arranged over a supporting plate installed along the base of the apparatus. Forty load cells were installed between each supporting block and the supporting plate so that the distribution of earth pressure on the trap door can be measured. The interaction between two adjacent blocks is avoided by setting the spacing at 0.05 mm. The tunneling process is simulated by lowering the trap door using a control jack. Fig. 3 shows an example of the surface settlement profiles induced by lowering the trap door 2 mm for different layer inclination angles and overburden pressures. The inclination angle was found to have a signifi- cant effect on the surface settlement trough. Symmetrical settlement profiles were observed for the vertically arranged blocks (h1 = 90). For the h1 = 30, the maximum surface settlement shifted towards a direction normal to the layer inclination angle (left of the trap door). Different behavior was found for the case of h1 = 60 where the maximum surface settlement shifted in the direction of the layer inclination angle (right of the trap door). H D 7
برای دانلود رایگان مقاله مدلسازی فیزیکی تونل ها در زمین نرم اینجا کلیک نمایید.
کلمات کلیدی:
[PDF]Centrifuge model test on the face stability of shallow tunnel https://www.stanford.edu/~borja/pub/ag2011(1).pdf by G Idinger - 2011 - Cited by 36 - Related articles Jun 22, 2011 - Shallow tunnels in soft ground are usually driven by shield tunnel boring ... proposed a failure criterion for the tunnel face in cohesive and frictional soil. Chambon and Corte [5, 6] reported on centrifuge model tests where the support pressure for face ... Physical model tests in the centrifugal field allow for. Physical Modelling in Geotechnics, Two Volume Set: Proceedings of ... https://books.google.com/books?isbn=0415889294 C.W.W. Ng, Y.H. Wang, L.M. Zhang - 2006 - Technology & Engineering in. soft. ground. S.K. Ahn Korea Construction Quality Research Center, Korea D.N. Chapman, A.H.C. Chan & D.V.L. Hunt 1 INTRODUCTION Physical modelling has served an important role in investigating the tunnelling-induced ground movements that occur above a single tunnel in various materials by many authors (Mair ... Geotechnical Aspects of Underground Construction in Soft Ground https://books.google.com/books?isbn=0203803582 Giulia Viggiani - 2012 - Technology & Engineering tunnels. and. deep. excavations. S.W. Jacobsz University of Pretoria, Pretoria, South Africa ABSTRACT: This paper presents an overview of the papers submitted for the session on numerical and physical modelling of tunnels and deep excavations, submitted for the proceedings of the Fifth International Symposium on ...
