Soil structure interaction

About: Soil structure interaction is a research topic. Over the lifetime, 3653 publications have been published within this topic receiving 48890 citations.

Seismic Soil-Structure Interaction in Buildings. I: Analytical Methods; Seismic Soil-Structure Interaction in Buildings. II: Empirical Findings

Abstract: The two papers describe trends of the apparent system periods, , and damping factors, , in recorded response of 56 ˜˜ T z0 buildings (A1 to A45, and B1 to B14 in Table 1 of part II) to 15 California earthquakes. The building, foundation, and soil are viewed as an equivalent linear system, excited by horizontal ground motion. Only inertial interaction is considered as ‘‘the more important effect for foundations without large, rigid base slabs or deep embedment’’ (by allowing one translation and rocking of the foundation). The kinematic interaction (modification of the free-field motion by the foundation in absence of inertial forces) is neglected as ‘‘second order.’’ Rocking and torsional excitation components of the incident motion, differential motions of extended foundations, warping of flexible foundations, and nonlinear soil response due to soilstructure interaction (SSI) are not mentioned. The papers aim to verify the ‘‘simplified analytical procedures similar to those in the BSSC and ATC codes.’’ This discussion (1) requests some clarifications; (2) suggests that time-dependent changes in (caused by nonlinear response of soil during SSI) should ˜ T have been included in the analysis; and (3) comments on the conditions when kinematic SSI should not be neglected. In view of the bold simplifications adopted in parts I and II, one would expect at least fair to good agreement of the predicted trends with the data, as a proof (albeit qualitative and rough) that the assumptions are justified. However, as the authors admit, there is ‘‘significant scatter in the data.’’ Table 1 in part II lists the confidence (A-acceptable; L-low) characterizing the quality of the available geotechnical data and the accuracy of identification. An L was assigned 15% of the 44 cases with base acceleration 0.25g. Does the proposed simplified analysis break down for progressively larger strains in the soil, e.g., base accelerations >0.15g?

Finite element parametric study of the behavior of segmental block reinforced-soil retaining walls

Abstract: Geosynthetic-reinforced-soil retaining walls with modular-block (segmental) facing have gained wide popularity because of their satisfactory performance and aesthetic appearance. A better understanding of the deformation of this wall system requires an analytical tool that is capable of considering the properties of soils, geosynthetic reinforcement, and soil–structure interactions in a realistic manner. In this paper, a validated finite element procedure was used with a hyperbolic soil model for conducting a series of analysis under working-stress conditions. The effects of the length, spacing and stiffness of reinforcement, the width, interaction and connection strength of the modular block, and the backfill and foundation soil properties were investigated. The deformation and lateral stress at the wall face, vertical stress along the base of the wall and the strains developed in the geosynthetic reinforcement are discussed. All design parameters were found to affect the wall performance with a certain ...

Seismic Behavior of Batter Piles: Elastic Response

Abstract: Several aspects of the seismic response of groups containing nonvertical piles are studied, including the lateral pile-head stiffnesses, the "kinematic" pile deformation, and the "inertial" soil-pile-structure response. A key goal is to explore the conditions under which the presence of batter piles is beneficial, indifferent, or detrimental. Parametric analyses are carried out using three-dimensional finite-element modeling, assuming elastic behavior of soil, piles, and superstructure. The model is first used to obtain the lateral stiffnesses of single batter piles and to show that its results converge to the available solutions from the literature. Then, real accelerograms covering a broad range of frequency characteristics are employed as base excitation of simple fixed-head two-pile group configurations, embedded in homogeneous, inhomogeneous, and layered soil profiles, while supporting very tall or very short structures. Five pile inclinations are considered while the corresponding vertical-pile group results serve as reference. It is found that in purely kinematic seismic loading, batter piles tend to confirm their negative reputation, as had also been found recently for a group subjected to static horizontal ground deformation. However, the total (kinematic plus inertial) response of structural systems founded on groups of batter piles offers many reasons for optimism. Batter piles may indeed be beneficial (or detrimental) depending on, among other parameters, the relative size of the overturning moment versus the shear force transmitted onto them from the superstructure.