Huygens' Principle: The capture of seismic energy by a soft soil layer

2004 ◽  
Vol 31 (13) ◽  
pp. n/a-n/a ◽  
Author(s):  
Cinna Lomnitz ◽  
Yunny Meas
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Seismic Energy ◽  
Huygens Principle

Performance evaluation of road embankment constructed using lightweight soils on an unimproved soft soil layer

2013 ◽  
Vol 160 ◽  
pp. 34-43 ◽  
Author(s):  
Tae-Hyung Kim ◽  
Tae-Hoon Kim ◽  
Gi-Chun Kang
Keyword(s):  
Performance Evaluation ◽  
Soft Soil ◽  
Soil Layer

scholarly journals CONCERNING THE EXTRACTION OF A SLACK SOIL LAYER FROM COMPRESSIBLE THICKNESS OF FOUNDATION STRATUM OF FINITE WIDTH FOUNDATIONS

2019 ◽  
Vol 7 (4) ◽  
pp. 49-56
Author(s):  
Zaven Ter-Martirosyan ◽  
Armen Ter-martirosyan ◽  
Valery DEMYANENKO
Keyword(s):  
Analytical Solutions ◽  
Soft Soil ◽  
Soil Layer ◽  
Horizontal Displacement ◽  
Creep Model ◽  
Shear Stresses ◽  
Finite Width ◽  
Relative Depth ◽  
Weak Layer ◽  
Horizontal Displacements

The paper provides a quantitative assessment of the deflected mode of foundation stratum of finite width foundation, in the compressible thickness of which there is a slack clay soil layer. A number of criteria for assessing the possibility or impossibility of extruding a slack layer depending on its strength and rheological properties, as well as the relative thickness of the layer to its length (h/l) and the relative depth of the layer (h/d) have been given. Closed analytical solutions are given to determine the rate of Foundation precipitation depending on the rate of extrusion of the weak layer, including taking into account the damped and undamped creep. The analytical solutions in the article are supported by the graphical part made with the help of the Mathcad program. Plots of changes in shear stresses in the layer along the x axis at different distances from the axis and at different values 0, contours of horizontal displacement velocities in the weak layer at different distances from the x axis, plots of horizontal displacement velocities in the middle of the weak layer and plots of horizontal displacement velocities in the weak layer at different distances from the x axis are given. As a calculation model for describing the creep of a slack layer, rheological ones of the soil using power and hyperbolic functions and their modifications have been considered. In addition, most modern rheological models that take into account soil hardening during creep have been considered. Based on these models, the problem is solved by means analytical and numerical methods using the Mathcad PC and the PLAXIS PC according to the Soft Soil Creep model. The graphical part shows the isofields of horizontal displacements for 300 days and 600 days and the corresponding contours of horizontal displacements.

Model Test of Bearing Capacity of WasteTire Assembly Foundation on Soft Soil Layer

2021 ◽  
Vol 69 (7) ◽  
pp. 263-269
Author(s):  
Me ti ◽  
Tri Harianto ◽  
Abdul Rachman Djamaluddin ◽  
Achmad Bakri Muhiddin
Keyword(s):  
Bearing Capacity ◽  
Model Test ◽  
Soft Soil ◽  
Soil Layer

Soft soil layer-tunnel interaction under seismic loading

2020 ◽  
Vol 98 ◽  
pp. 103329 ◽  
Author(s):  
Qiangqiang Sun ◽  
Daniel Dias ◽  
Luis Ribeiro e Sousa
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Seismic Loading

Stability Analysis of Narrow and Long Excavation in Soft Soil Area

2015 ◽  
Vol 723 ◽  
pp. 372-376
Author(s):  
Shi Chong Zhou ◽  
Li Li Gao ◽  
Dong Hui Wu ◽  
Yang Liu ◽  
Dong Yue Wang ◽  
...  
Keyword(s):  
Reduction Method ◽  
Soft Soil ◽  
Soil Layer ◽  
Spatial Effect ◽  
Strength Reduction ◽  
Strength Reduction Method ◽  
Present Stage ◽  
Support Structure ◽  
Finite Element Software ◽  
Sliding Stability

At the present stage of excavation design,the embedded depth of braced structure should meet the requirement of circular sliding stability when the bottom is soft soil. By increasing the embedded depth of support structure, the requirements of stability could be meet. In the normal design, the support structure must penetrate the soft soil layer when the bottom exist soft soil. While when the excavation is narrow and long, because of the obviously spatial effect, there is no need to determine the embedded depth based on the general circular sliding stability. In this paper, based on one the project example, calculate and analyze the similar stability using strength reduction method through the finite element software Plaxis and Midas.

The Influence of Pavement Construction on Embankment Settlement in Highway Extension Project

2013 ◽  
Vol 361-363 ◽  
pp. 1787-1793
Author(s):  
Xian Lin Wei ◽  
Yi Min Wang ◽  
Ze Min Zeng ◽  
Luo Zhang
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Composite Foundation ◽  
Standard Requirement ◽  
Construction Period ◽  
Small Influence ◽  
Load Carrying ◽  
Pavement Construction ◽  
Layer Deformation

In order to reduce the soft soil layer deformation due to pavement construction, equal preloading of pavement is usually adopted after embankment filling in soft ground region. But as the ground treatment effect of pile-supported and geosynthetic reinforced embankment is satisfactory with great load-carrying ability, the necessity of applying equal preload is worth discussing. Combined with the practice of Guangzhou-Sanshui expressway widening project, the settlements in surveying sections during the paving construction period in extension area were monitored. The monitoring data shows that pavement load had small influence on embankment settlement: the uneven settlement between newly widen and existing road is small and the post-construction settlements are controlled within the standard requirement. On the premise of guaranteeing the construction quality of composite-foundation and filling compaction degree, it is unnecessary to take equal preloading to avoid excessive embankment settlement caused by the pavement structure.

Amplification Effects of Thin Soft-Surface Layers

2016 ◽  
Vol 32 (4) ◽  
pp. 2109-2126 ◽  
Author(s):  
W. D. Liam Finn ◽  
Francisco Ruz
Keyword(s):  
Soft Soil ◽  
Soil Layer ◽  
Tohoku Earthquake ◽  
Response Spectra ◽  
Surface Layers ◽  
Soft Layer ◽  
The 2011 Tohoku Earthquake ◽  
Amplification Factors ◽  
Soft Surface ◽  
Using Data

The amplification effects of shallow soft-surface layers with respect to an underlying hard-soil layer or rock are studied using data recorded from the 2011 Tohoku earthquake. Twenty-four sites have been studied with depths to rock ranging from 4–30 m. At each site, two records were available: one in rock at the bottom of the borehole at depths of 100–500 m and one on the surface of the soft-soil layer. Analyses of the soil-rock columns were conducted using the program SHAKE. Good agreement was found between calculated and recorded surface spectra, which demonstrated the reliability of SHAKE analyses for the sites under study. Therefore, SHAKE analyses were used to determine the outcrop motions at the top of rock. Amplification factors were determined by comparing characteristics of the surface and outcrop motions such as Fourier and response spectra. Computed amplification factors were correlated with V S30, V soil, and soft layer period, T = 4 H/ V soil. The results show clearly that the most reliable correlations for estimating the amplification of soft shallow surface layers less than 30 m are those based on V S30 and soft layer period, T.

Analytical Solution of 1-D Viscoelastic Consolidation of Soft Soils with Fractional Maxwell Model

2012 ◽  
Vol 157-158 ◽  
pp. 419-423
Author(s):  
Ya Peng Zhang ◽  
Feng Gao
Keyword(s):  
Analytical Solution ◽  
Soft Soil ◽  
Soil Layer ◽  
Viscoelastic Model ◽  
Integral Form ◽  
Maxwell Model ◽  
One Dimensional ◽  
The Laplace Transform ◽  
Fractional Maxwell Model ◽  
The One

Considering the rheological characteristics of soil, think the fractional maxwell with viscoelastic model can be described, the fractional maxwell model into integral form of saturated soft soil layer, the one dimensional compression, through the Laplace transform problems get instantaneous loading and single stage, the analytical solution of the loading conditions.

Nonlinear Consolidation Analysis of Soil-Cement Pile

2011 ◽  
Vol 94-96 ◽  
pp. 504-509
Author(s):  
Chi Wang ◽  
Guo Xing Xia ◽  
Ming Huang
Keyword(s):  
Initial Conditions ◽  
Soft Soil ◽  
Soil Layer ◽  
Time Interval ◽  
Consolidation Process ◽  
Volume Compressibility ◽  
Computing Unit ◽  
Coefficient Of Permeability ◽  
Soil Cement ◽  
Nonlinear Consolidation

A few consolidation solutions of soil-cement pile have been derived by the assumption that the coefficient of volume compressibility and coefficient of permeability of soil and pile is constant. However, the value of coefficient of volume compressibility and coefficient of permeability of soil and pile varies along depth during the consolidation process with the increment of effective stress of soft soil and pile. In this paper, the e–logσ′ and e–logk linear relationship is used to describe the stress-strain and strain-permeability coefficient relationship of soft soil. The nonlinear compressive character of soil-cement pile is considered. The semi-analytical solution is obtained by dividing the computing unit and segmenting the consolidation time. The coefficient of volume compressibility and coefficient of permeability of soil and pile can be assumed to be constant at any soil layer during any time interval. The initial conditions of computing unit can be confirmed by the calculation results of last time interval. Finally, some nonlinear consolidation properties of composite ground are analysed.

Finite Element Analysis of Bridge-Foundation Interaction System under Horizontal Seismic Excitation

2014 ◽  
Vol 490-491 ◽  
pp. 691-694
Author(s):  
Shou Long Chen ◽  
Chun Yi Cui ◽  
Yan Sun
Keyword(s):  
Finite Element ◽  
Seismic Waves ◽  
Soil Depth ◽  
Soft Soil ◽  
Soil Layer ◽  
Element Analysis ◽  
Interaction System ◽  
Frequency Components ◽  
Bridge Foundation ◽  
Pile Length

Based on Newmark-β gradual integration method and elastic-plastic mechanical theory, numeriacl analyses of effects of soft soil depth and thickness and pile length on the characteristics of horizontal seismic response of bridge-foundation interaction system with soft layers conducted by using finite element program Midas/GTS. The numerical results show that: (1) The high frequency components of seismic excitations can be filtered and the low frequency components are amplified correspondingly when seismic waves are transmitted through soft soil layer, and thicker and lower soft soil layer can amplified this effects; (2)The extremum force of abutment shows decreases first then increases with depth decreasing, and displacement of abutment top and bottom has the same law with seismic waves, and the thicker and lower soft soil layer or shorter piles can aggravate abutment force and deformation; (3)Shear extremal stress shows decrease from top to bottom and the thicker and lower soft soil layer or shorter piles are adverse on piles; (4)Moment extremal expresses first increase then decrease with pile length and the lower and thicker soft soil layer or shorter piles can enlarged piles moment.

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