Lateral earth pressure

About: Lateral earth pressure is a research topic. Over the lifetime, 5334 publications have been published within this topic receiving 62552 citations.

Resultant Force of Lateral Earth Pressure in Unstable Slopes

Abstract: Traditionally, resultant force of lateral earth pressure serves as the basis for design of nearly vertical walls. Conversely, slopes are designed to be internally stable using a factor of safety approach. However, with the availability of heavy facing elements such as gabions, steep slopes are increasingly being constructed. Steep slopes are considered to be unstable unless supported; that is, such slopes require facings to resist lateral earth pressure. Extending Coulomb's formulation to such slopes may not be conservative as a planar slip surface may not be critical. Presented are the results of a formulation to find the resultant lateral force which utilizes a log spiral failure mechanism. Unlike Caquot and Kerisel or Coulomb, the soil-facing interface friction is assumed to act on segments of vertical surface only, thus replicating the geometry of stacked rectangular facing units. Given the batter, the backslope, the height, the interface friction, and the unit weight and design friction angle of the backfill, one can quickly determine the corresponding lateral earth pressure coefficient. Formulation assuming the interface friction is acting on an imaginary surface inclined at the batter angle, essentially equivalent to Coulomb and Caquot and Kerisel, is also presented. Its results show that for batters up to 20°, the common approach of using the Coulomb method, including the assumed interface friction direction to coincide with the batter, yields results that are quite close to those stemming from the log spiral analysis. Hence, use of Coulomb's analysis for such small batters is reasonable as its formulation is simple. However, the lateral resultant is grossly underestimated for larger batters, especially when Coulomb analysis is used.

Lateral earth pressure sensor embedment method and device in earth

Abstract: The invention relates to a method for embedding a side-direction soil pressure sensor in the soil and a device thereof, which belongs to the technical field of construction engineering. The device comprises a sensor installation pipe, an extension pipe, a soil pressure sensor, a protective steel jacket, a U-shaped protective steel clip, a rigging screw, a connector pipe, a data transmission guide wire and a data collection instrument. The data transmission guide wire of the soil pressure sensor is connected with the data collection instrument. A notch is arranged in the center of the sensor installation pipe; the soil pressure sensor is put into the protective steel jack and then the soil pressure sensor and the protective steel jack are embedded in the notch; the U-shaped protective steel clip and the rigging screw are used to fix; the connector pipe is used to extend the sensor installation pipe and the extension pie to the design length; the pipes are put into a soil drilling hole; the guide pipes are fixed temporarily, and then fine sand is backfilled into the drilling hole; after the fine sand is consolidated, and the side direction soil pressure test is carried out. The invention has the advantages of convenient installation and operation, economy and practicality, high survival rate of the sensor embedded, capability of quite accurately measuring the side direction soil pressure in the soil, and accurate and reliable test result.

SPH-FEM coupled simulation of SSI for conducting seismic analysis on a rectangular underground structure

Abstract: A reliable simulation of soil–structure interaction (SSI) is the precondition for understanding properly the dynamic response characteristics and earthquake disaster mechanism of underground structures. This paper adopts Smoothed Particle Hydrodynamics-Finite Element Method (SPH-FEM) coupled method to address the SSI issue. The coupled method takes advantage of the convenience of SPH in simulating the particle features of soils. The advantages of the presented method are capable of tracking the location information and motion of soils at any moment, and the deformation process inside the near-structure soils can also be captured during an earthquake. Meanwhile, it can also be made use of the accuracy of FEM in handling boundary issues and solving structural dynamics. Analysis results indicate that not only the racking deformation mode is observed, but also a rocking vibration mode that is non-negligible can be found for a rectangular underground structure under transverse seismic excitation. The rocking vibration mode is shown as the incline of top and bottom slabs, which is caused by the asymmetric seismic action on two opposite side-walls resulting from the different soil–structure contact status. The analysis clearly shows that the seismic earth pressure is a result of the interaction between soil and structure in an earthquake. The distribution and magnitude of seismic earth pressure are influenced by the magnitude of soil deformation and soil–structure contact status.

Behavior of a Stiff Clay behind Embedded Integral Abutments

Abstract: Integral bridges can significantly reduce maintenance and repair costs compared with conventional bridges. However, uncertainties have arisen in the design as the soil experiences temperature-induced cyclic loading behind the abutments. This paper presents the results from an experimental programme on the behavior of a stiff clay behind embedded integral abutments. Atherfield Clay specimens were subjected to the stress paths and levels of cyclic straining that a typical integral bridge abutment might impose on its retained soil. The results show that daily and annual temperature changes can cause significant horizontal stress variations behind such abutments. However, no increase in lateral earth pressure with successive cycles was observed for this typical stiff clay, and the stress-strain behavior and stiffness behavior were not influenced by continued cycling. The implications of the results for integral abutment design are discussed.