关键词: 软基, 固结, 粉细砂, 排水垫层, 导水系数, 塑料排水带

Abstract: In engineering practice design parameters of drainage mats for consolidation method, such as drainage mat thickness, permeability coefficient, etc, are highly related to engineering experience. Silty sand is not recommended for drainage mat by engineering design specifications. Based on the prototype measurement of a certain reclamation project in Shanghai, characteristics of silty sand drainage mats of sea dike on muck foundation are studied via nonlinear FEM; and the impact of key factors on consolidation, such as mat permeability coefficient, mat thickness, mat length and relative permeability of body, etc, is further studied. On that basis, it is put forward that using transmissibillity coefficient of drainage mat as control parameter for design. Thus, the relating design formula for drainage mat, covering those factors, is presented accordingly; and it provides technical support for the design of drainage mat by using silty sand instead of medium sand or coarse sand. It is found that using silty sand to construct drainage mat is feasible in some project.

Key words: soft foundation, consolidation, silty sand, drainage mat, transmissibillity coefficient, plastic drainage