Bearing capacity charts of soft soil reinforced by deep mixing

A series of preliminary design charts were developed to predict the bearing capacity of fully and partially penetrated deep mixing (DM) of soft soil. The charts were produced by a new numerical analysis tool based on discontinuity layout optimisation (DLO) in which a previously proposed homogenisation method was used to define the improvement area. To measure the applicability of implementation of the homogenisation method in the DLO, a series of validation processes was performed against several previous studies under uniform soil strength. A new empirical solution was developed from the DLO method using the homogenisation method for the bearing capacity of soft ground under uniform soil strength, improved by the fully penetrated DM method. Results produced by the DLO approach were compared with existing analytical solutions and better agreement was found from the present model. The charts consider variation in improvement area ratio, column length and strength, and foundation width for the fully and partially penetrated DM cases. The simulations were related to real field cases in which the strength characteristics of soft soil increase with depth. An example is given to demonstrate use of the charts

Evaluation of Lateral Capacity of Pile Foundation Using Finite Element Method in Layered Soil

The behavior of the pile subjected to lateral load depends on subsoil condition, sectional properties of pile, boundary condition of pile at top and bottom, and rigidity of the structure. Early attempts have been made to understand the response of the pile subjected to lateral loads using finite difference method (FDM) to obtain non-dimensional curve. Such curves are being used for determination of ultimate horizontal capacity as well as deflection, shear force, bending moment, soil reaction, etc., under design horizontal load. In the current study, an effort was made to determine the lateral load capacity using finite element method (FEM) for pile diameter, varying from 0.15 to 2.0 m in layered soil. The performance of the pile–soil system depends on the properties of soil and pile. The results obtained from the study indicated that the lateral capacity of pile foundation depends on cross-sectional area and material of pile, boundary conditions of the pile at top and bottom, and horizontal subgrade modulus of top soil (6D, where D is diameter of pile). For an increase in the diameter of pile (D–2D), lateral capacity of pile is increased by 2.5 times. © 2020, Springer Nature Singapore Pte Ltd