Pile-Soil System Response in a Cohesive Soil

AbstractThis paper reviews the complex factors interacting in the movement of contaminants in soil subject to seasonal freezing. This includes those relevant to the soil itself, the contaminant itself, and environmental factors, all of which must be understood for prediction and effective design of remediation. Numerical modelers, as well as laboratory researchers examining behavior of small elements of the soil system, require reliable information on the range of full-scale system responses, but it is not feasible to acquire this by full-scale tests. Even field workers benefit from this information in planning data collection. Small physical models of contaminants moving through soil have routinely been limited in their usefulness because of differences in model fluid pressures and soil stresses, compared to full-scale conditions. However, small-scale centrifuge modeling presents the opportunity to produce correct and rapid physical simulation of full-scale system response using field soil and real contaminants, under the range of different boundary conditions. This paper discusses the existing recent centrifuge modeling work that supports the thesis that the technique can be applied to understanding and analyzing this complex problem. Five studies are reviewed: one on simulation of soil freezing effects in the absence of contaminants; three on the simulation of contaminant movement through saturated and unsaturated unfrozen soil, and heat transport effects through the fluid phase of unfrozen soils; and one that simulates the combination of contaminant movement in freezing soil.

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Simplified Soil–Structure Interaction Analysis for High-Tech Industrial Buildings Subjected to Forced Vibrations

International Journal of Structural Stability and Dynamics ◽

10.1142/s021945541450031x ◽

2015 ◽

Vol 15 (01) ◽

pp. 1450031 ◽

Cited By ~ 2

Author(s):

Shi-Shuenn Chen ◽

Jun-Yang Shi

Keyword(s):

Soil Structure ◽

Interaction Analysis ◽

Dynamic Responses ◽

Soil Structure Interaction ◽

High Tech ◽

System Response ◽

Soil System ◽

Structure Interaction ◽

Industrial Buildings ◽

Design Values

To implement a safe and reliable design for high-tech industrial buildings, the system response should be accurate enough to include the effect of soil–structure interaction (SSI). This study proposed a simplified building–soil system to analyze the dynamic responses, using parameters that are representative of the practical design values for typical semiconductor fab structures in Taiwan. The responses of the simplified building–soil system subjected to dynamic horizontal loadings are verified in the frequency domain and time domain. The dynamic responses of the simplified building–soil system are found to agree very well with those of the complete system obtained by the half-space theory and by the numerical analysis program. It is shown that the proposed simplified system can effectively analyze the coupled SSI effects in the translational and rotational directions. It is also found that the structural responses may deviate significantly by neglecting the coupling of horizontal and rocking motions as the building has a deeper embedded foundation and a stiffer upper structure. The proposed method can be applied to the vibration analysis of high-tech industrial buildings subjected to dynamic loadings.

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Nonlinear cyclic behavior of laterally loaded pile in cohesive soil

Canadian Geotechnical Journal ◽

10.1139/cgj-2013-0099 ◽

2014 ◽

Vol 51 (2) ◽

pp. 129-143 ◽

Cited By ~ 22

Author(s):

Mehdi Heidari ◽

Mojtaba Jahanandish ◽

Hesham El Naggar ◽

Arsalan Ghahramani

Keyword(s):

Mechanical Properties ◽

Cohesive Soil ◽

Offshore Structures ◽

Cyclic Behavior ◽

Winkler Foundation ◽

Backbone Curve ◽

Laterally Loaded Piles ◽

Soil System ◽

Pile Interaction ◽

Laterally Loaded

Pile foundations may be subjected to lateral dynamic loads due to different hazards, such as impact of ships on bridge piers or jetties during berthing, wave and wind actions on offshore structures, and seismic wave motion on different buildings. The beam on nonlinear Winkler foundation (BNWF) approach is widely employed for predicting the response of piles under lateral loading because of its simplicity and practical accuracy. p–y curves are employed to represent the nonlinear soil reactions within the framework of the BNWF approach. However, they are empirically obtained from limited full-scale field tests and are not unique, accounting only for the pile width and not its mechanical properties. On the other hand, the strain wedge (SW) method allows the assessment of three-dimensional (3-D) soil–pile interaction of laterally loaded piles by incorporating soil continuity and pile properties as well as soil properties. In this study, the nonlinear p–y curves generated by the SW model are implemented as the backbone curve of developed BNWF model to effectively account for different response features of the pile–soil system. These features include the soil and pile nonlinear behavior, cyclic degradation of soil stiffness and strength, formation of soil–pile gap, and radiation damping. Two case studies of cyclic lateral load tests for single piles are investigated to examine the effects of soil degradation and gap formation on the response of laterally loaded piles embedded in cohesive soil. The developed model is shown to be capable of representing different soil–pile interaction features observed in experiments. The predictions of the developed BNWF model are in good agreement with experimental results. Finally, a comprehensive parametric study is performed to compare the predictions of the SWM-based model of the pile response under cyclic loading with that obtained from the conventional p–y curve–based model for different pile cross-section configurations, mechanical properties (strength and stiffness), and soil strength–stiffness.

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Passive soil heating using an inexpensive infrared mirror design – a proof of concept

SOIL ◽

10.5194/soil-1-631-2015 ◽

2015 ◽

Vol 1 (2) ◽

pp. 631-639 ◽

Cited By ~ 4

Author(s):

C. Rasmussen ◽

R. E. Gallery ◽

J. S. Fehmi

Keyword(s):

Heat Capacity ◽

Organic Matter Content ◽

Soil Surface ◽

Matter Content ◽

System Response ◽

Proof Of Concept ◽

Soil Warming ◽

Partial Shading ◽

Soil System ◽

Soil Heating

Abstract. There is a need to understand the soil system response to warming in order to model the soil process response to predicted climate change. Current methods for soil warming include expensive and difficult to implement active and passive techniques. Here we test a simple, inexpensive in situ passive soil heating approach, based on easy to construct infrared mirrors that do not require automation or enclosures. The infrared mirrors consisted of 61 × 61 cm glass panels coated with infrared reflecting film. The mirrors as constructed are effective for soil heating in environments typified by an open vegetation canopy. Mirror tests were performed on three soils of varying texture, organic matter content, and heat capacity in a warm semi-arid environment. Results indicated that the infrared mirrors yielded significant heating and drying of soil surface and shallow subsurface relative to unwarmed control treatments, and that warming and drying effects were soil specific with greater potential warming on soils with lower volumetric heat capacity. Partial shading from the mirror frame did produce periods of relative cooling at specific times of the day but overall the mirrors yielded a net soil warming. The results demonstrate proof of concept that the infrared mirrors may be used to passively heat the near soil surface, providing an inexpensive, low-maintenance alternative to other passive and active soil heating technologies.

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Analytical Solution of Laterally Loaded Free-Head Long Piles in Elasto-Plastic Cohesive Soils

Mathematics ◽

10.3390/math9161961 ◽

2021 ◽

Vol 9 (16) ◽

pp. 1961

Author(s):

Ayman Abd-Elhamed

Keyword(s):

Closed Form ◽

Closed Form Solution ◽

Bending Moment ◽

Cohesive Soil ◽

Form Solution ◽

Cohesive Soils ◽

Fe Model ◽

Soil System ◽

Soil Medium ◽

Laterally Loaded

This research study presents a closed form solution of responses of laterally loaded long piles embedded on cohesive soils with a constant subgrade modulus. The surrounding soil medium is modelled as elastic-perfectly plastic. The closed form solution is derived by solving the governing differential equation of the pile–soil system. The most popular numerical computation software package MATLAB is utilized for the implementation of solutions. The provided analytical method reliably calculates the pile head deflection and bending moment required for engineering design purposes. Results are discussed and verified with solutions of an equivalent three-dimensional finite element (FE) model developed using ANSYS software. It was concluded that the proposed analytical model could efficiently provide the exact solution of embedded piles in elasto-plastic cohesive soil under lateral loads.

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