Settlement Calculation Of Foundation Research Articles

The Effects of Physical Properties on the Compression Modulus of Coastal Fully-Weathered Red Sandstone: Consolidation Compressibility and the Settlement Calculation of Foundation

Xu, H.; Rui, X.; Wang, Z.; Qiu, Z.; Cai, L.; Zhang, Z., and Zhao, M., 2022. The effects of physical properties on the compression modulus of coastal fully-weathered red sandstone: Consolidation compressibility and the settlement calculation of foundation. Journal of Coastal Research, 38(4), 870–884. Coconut Creek (Florida), ISSN 0749-0208. The compressibility of rock and soil can be characterized by compression modulus, which is influenced by multiple physical properties, so it is difficult to be quickly and accurately measured on-site; thus, comprehensive exploration of their influence on the compression modulus is significant. In this paper, the physical properties of water content, fines content, and relative compaction, which can be easily measured on-site, were selected. Based on the orthogonal combination consolidation test, the variation of compression modulus of fully weathered red sandstone was investigated. Then, the relationship between compression modulus and the combination of physical properties was learned using the decision tree algorithm model for the first time, which can perform accurate and real-time prediction. The results showed that the cubic and quaternary polynomials can accurately represent the variation of compression modulus with a single physical property, and the model based on a 10-level decision tree algorithm can learn the coupling relationship between compression modulus and combination of physical properties to accurately calculate and predict the compression modulus. The algorithm model can be further applied to calculate the settlement of foundation in fully weathered red sandstone stratum with different water content during the precipitation process, which can effectively guide the engineering construction. This research provides a reference for the study of consolidation compressibility of fully weathered red sandstone and similar stratum, as well as the settlement calculation of foundation.

Calculation of foundation settlement on a overconsolidated base

The article presents experimental and theoretical bases of overconsolidated soils deformation. The effect of preliminary soil compaction on its deformation under conditions of compression is shown. Based on this dependence, a method is proposed for calculating the foundation settlement on a overconsolidated base, taking into account the pre overburden pressure. The obtained method is compared with the results of the problem solution by the finite element method.

Improvement of the Formula of Foundation Settlement which Considering Three-Dimensional Transform

In engineering design and construction, the adverse effect would be prevented, if we can estimate and consider the the foundation transformation and control or take advantage of it.Calculating the building foundation settlement. we should consider the influence of lateral deformation of foundation soil. In this paper we replace e-lgp curve with e-p curve on basis of the calculation theory foundation settlement considering three-dimensional transformation, it makes the calculation of foundation settlement more simplified and accurate.

Determining Preconsolidation Pressure of the Lakeside New District Soft Clay of Hefei Based on Casagrande Method by Matlab

The preconsolidation pressure is an important index to determine the stress history of soil and also a major calculation parameter for the analysis of soil stratum’s deformation in the different stress history. Casagrade method is worldwide applied to determine the preconsolidation pressure. On the basis of research on consolidation test about the lakeside new district soft clay of Hefei by high pressure consolidation apparatus, and conformed to Casagrande method, the paper adopts quartic polynomial and least square method to fit the compression curve, and the preconsolidation pressure of the lakeside new distract soft clay of Hefei is determined by matlab software. The result provides reference for the calculation of foundation settlement considering stress history.

A Servo/Suction-Controlled Ring Shear Apparatus for Unsaturated Soils: Development, Performance, and Preliminary Results

Abstract In recent years, the key hypotheses of most constitutive frameworks postulated for unsaturated soils have been validated via suction-controlled oedometer, triaxial, and direct shear testing. These techniques only allow for the application of loads along limited modes and levels of soil deformation. It is well known today that a vast majority of geotechnical infrastructure made of compacted soil, or resting on unsaturated ground, involves a wide range of deformations. Calculation of foundation settlement, for instance, requires a good estimation of soil stiffness at relatively small strains. Analysis of slopes, embankments, and soil bearing capacity, on the other hand, requires good estimations of shear strength, from peak to residual. To date, however, there is limited experimental evidence of unsaturated soil behavior under large deformations while being subjected to controlled-suction states. This paper introduces a fully servo/suction-controlled ring shear apparatus that has been made suitable for testing unsaturated soils at large deformations via axis-translation technique. The paper outlines the full development of the apparatus, including details of its main components, assembling, and performance verification against the original Bromhead device. A preliminary series of suction-controlled ring shear tests was accomplished on several statically compacted samples of silty sand. Residual friction angle with respect to matric suction, i.e., residual beta angle, was found to remain virtually constant, regardless of the applied level of net normal stress. The results suggest that a conceptual residual shear strength framework for unsaturated soils, similar to that postulated for peak shear strength, could eventually be devised as more experimental evidence of this kind is made available.

Fast analytical estimation of the influence zone depth, its numerical verification and FEM accuracy testing

For the calculation of foundation settlement it is recommended to take into account so called influence zone inside the subsoil bellow the foundation structure. Influence zone inside the subsoil is the region where the load has a substantial influence on the deformation of the soil skeleton. The soil skeleton is pre-consolidated or over consolidated due to the original geostatic stress state. An excavation changes the original geostatic stress state and it creates the space for the load transferred from upper structure. The theory of elastic layer in Westergard manner is selected for the vertical stress calculation. The depth of influence zone is calculated from the equality of the original geostatic stress and the new geostatic stress due to excavation combined with the vertical stress from the upper structure. Two close formulas are presented for the influence zone calculation. Using ADINA code we carried out several numerical examples to verify the proposed analytical formulas and to enhance their use in civil engineering practice. Otherwise, the FEM code accuracy can be control.

Foundation Design of Anchored Walls, Bay Springs Lock, Mississippi

Bay Springs Lock, the northernmost structure on the Tennessee-Tombigbee Waterway, was designed for a normal lift of 84 ft. As a result of the high walls and the relatively low strength of the foundation rock, deep and extensive excavations for necessarily large gravity wall monoliths would be required, with attendant high costs. To reduce these costs, an alternate design using anchored wall monoliths was proposed. Because this would be the first such design by the U.S. Army Corps of Engineers, a large test excavation and a great deal of subsurface exploration and laboratory testing was warranted. The rock mass would be an integral part of the lock walls; therefore, selection of realistic and reliable rock design parameters was critical. The geotechnical design included the selection of rock mass strengths, as well as the calculation of foundation settlement, bearing capacity and slope stability. Utilizing the developed foundation data, the lock design was completed and the lock constructed such that the monoliths were anchored to the rock mass with 116 tendons that ranged in length from 80 ft to 175 ft.

Calculation of foundation settlement allowing for variations in the deformation properties of ground (in Russian) : Krivorotkov, A P Russia: Minist Vyssh Srednego Spets Obrazov, Izv VUZ Stroit Arkhit, N3, 1977, P17–22

Calculation of foundation settlement allowing for variations in the deformation properties of ground (in Russian) : Krivorotkov, A P Russia: Minist Vyssh Srednego Spets Obrazov, Izv VUZ Stroit Arkhit, N3, 1977, P17–22