Three-dimensional finite-element analysis of panel installation of a ultra-deep diaphragm wall
QIN Hui-lai1, 2, LI Feng3, GUO Yuan-cheng4
1. Key Laboratory of Road Structure & Material of Ministry of Transport,Research Institute of Highway Ministry of Transport, Beijing 100088, China; 2. Technical Center, China State Construction Engineering Corporation, Beijing 101300, China; 3. China Construction Second Engineering Bureau Ltd., Beijing 100054, China; 4. Civil Engineering School, Zhengzhou University, Zhengzhou 450002, China
Abstract：It is well known that installation of diaphragm walls in heavily overconsolidated soils will cause substantial ground deformation and can influence the behaviour of the wall during the main excavation process. However, it has not been considered that the installation effect of the panels of ultra-deep diaphragm wall in normally consolidated soils. A popular commecial finite element software, ABAQUS, is employed to simulate the panel installation process of a ultra-deep diaphragm wall in normally consolidated clay. The clay plasticity soil model in ABAQUS, which is based on the modified Cam clay model, is selected to simulate the clay characteristic. The physical meanings of the parameters for the clay model in ABAQUS are discussed, and the methods to decide the parameter values from triaxial compression tests or oedometer tests are presented. A formula for the initial void ratio and the mean effective stress in the field is deduced and used in the simulating by ABAQUS. Three-dimensional numerical models are established to simulate the installation process of the panels, including excavation under a bentonite support, placing and subsequent hardening of concrete. The deformation characteristics of the soil layers induced by the construction of wall panels as well as the influences from the width of the wall panels and the weight of the bentonite slurry are studied.
[1] COWLAND J W, THORLEY C B B. Ground and building settlement associated with adjacent slurry trench excavation[C]// Proceedings of the Third International Conference on Ground Movements and Structures, University of Wales Institute of Science and Technology. London, 1985: 723-738． [2] GUNN M J, CLAYTON C R I. Installation effects and their importance in the design of earth retaining structures[J]. Geotechnique, 1992, 42(1): 137-141. [3] DE MOOR E K. An analysis of bored pile/diaphragm wall installation effects[J]. Géotechnique, 1994, 44(2): 341-347. [4] NG C W W, LINGS M L, SIMPSON B, et al. An approximate analysis of the three dimensional effects of diaphragm wall installation[J]. Géotechnique, 1995, 45(3): 497-507. [5] DING Y C, WANG J H. Numerical modeling of ground response during diaphragm wall construction[J]. Journal of Shanghai Jiaotong University (Science), 2008, 13(4): 1-6. [6] GOURVENEC S M, POWRIE W. Three dimensional finite element analysis of diaphragm wall installation[J]. Géotechnique, 1999, 49(6): 801-823. [7] POWRIE W. KANTARTZI C. Ground response during diaphragm wall installation in clay: centrifuge model tests[J]. Géotechnique, 1996, 46 (4): 725-739. [8] HELWANY S. Applied soil mechanics with ABAQUS applications[M]. New York: John Wiley & Sons, 2007. [9] WOOD D V. Soil behavior and critical state soil mechanics[M]. London: Cambridge University Press, 1990. [10] LINGS M L, NG C W W, NASH D F T. The lateral pressure of wet concrete in diaphragm wall panels cast under bentonite[J]. Proceedings of the Institution of Civil Engineering: Geotechnical Engineering, 1994, 107(3): 163-172.
