scholarly journals 1-D CONSOLIDATION OF SOFT CLAY SUBJECTED TO CYCLIC LOADING USING LEM

2018 ◽  
Vol 30 (2) ◽  
Author(s):  
Omar El Gendy ◽  
Ibrahim El Arabi ◽  
Ibrahim El Kersh
Keyword(s):  
Cyclic Loading ◽  
Initial Stress ◽  
Soft Clay ◽  
Equation Method ◽  
Storage Tanks ◽  
Soil System ◽  
Consolidation Settlement ◽  
Different Types ◽  
Degree Of Consolidation ◽  
Port Said

In this paper, a numerical modification is carried out on the Layer Equation Method (LEM) of El Gendy and Herrmann to be applicable for analyzing 1-D consolidation of soft clay subjected to cyclic loading. The LEM is applicable for multilayered soil system subjected to variable initial stress along depth. The proposed solution is used for normally and over consolidated clays subjected to different types of cyclic loading considering the basis of the method of Toufigh and Ouria. The LEM is incorporated by the authors into the geotechnical software ELPLA and is verified with two verifications. The results of the verifications are close to the references results. The proposed solution is applied for circular storage tanks as a structure subjected to cyclic loading from filling and discharging cycles. An application was held to study the effect of cyclic loading on two zones located at Port-Said city in Egypt using real soil data from real sites. The results of the average degree of consolidation and consolidation settlement versus time are presented for both zones.

Sloshing Response of Floating Roofed Liquid Storage Tanks Subjected to Earthquakes of Different Types

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
F. G. Golzar ◽  
R. Shabani ◽  
S. Tariverdilo ◽  
G. Rezazadeh
Keyword(s):  
Ground Motions ◽  
Far Field ◽  
Storage Tanks ◽  
Natural Period ◽  
Design Spectrum ◽  
Long Period ◽  
Lateral Forces ◽  
Different Types ◽  
Hamiltonian Variational Principle ◽  
Stress Patterns

Using extended Hamiltonian variational principle, the governing equations for sloshing response of floating roofed storage tanks are derived. The response of the floating roofed storage tanks is evaluated for different types of ground motions, including near-source and long-period far-field records. Besides comparing the response of the roofed and unroofed tanks, the effect of different ground motions on the wave elevation, lateral forces, and overturning moments induced on the tank is investigated. It is concluded that the dimensionless sloshing heights for the roofed tanks are solely a function of their first natural period. Also it is shown that while long-period far-field ground motions control the free board height, near-source records give higher values for lateral forces and overturning moments induced on the tank. This means that same design spectrum could not be used to evaluate the free board and lateral forces in the seismic design of storage tanks. Finally, two cases are studied to reveal the stress patterns caused by different earthquakes.

A Change of Undrain Shear Strength of Soft Ground during Consolidation Process

2014 ◽  
Vol 513-517 ◽  
pp. 269-272
Author(s):  
Yeong Mog Park ◽  
Ik Joo Um ◽  
Norihiko Miura ◽  
Seung Cheol Baek
Keyword(s):  
Shear Strength ◽  
Soft Clay ◽  
Confining Pressure ◽  
Triaxial Tests ◽  
Test Results ◽  
Exponential Equation ◽  
Consolidation Process ◽  
Degree Of Consolidation ◽  
Clay Ground ◽  
Strength Increment

The purpose of this study is to investigate the undrain shear strength increment during consolidation process of soft clayey soils. Thirty kinds of laboratory triaxial tests have been performed using undisturbed and remolded Ariake clay samples with different degree of consolidation and 5 kinds of confining pressure. Test results show that well known linear equation proposed by Yamanouchi et al.(1982) is overestimated the strength of undisturbed soft clay ground in the process of consolidation. A new simple and reasonable exponential equation proposed in this paper.

RESPONSE OF SOFT CLAY STRATA AND CLAY-PILE-RAFT SYSTEMS TO SEISMIC SHAKING

2007 ◽  
Vol 01 (03) ◽  
pp. 233-255 ◽  
Author(s):  
SUBHADEEP BANERJEE ◽  
SIANG HUAT GOH ◽  
FOOK HOU LEE
Keyword(s):  
Soft Clay ◽  
Ground Surface ◽  
Model Tests ◽  
Pile Foundations ◽  
Kaolin Clay ◽  
Natural Period ◽  
Soil System ◽  
Centrifuge Model ◽  
Inertial Loading ◽  
Centrifuge Model Tests

The behavior of pile foundations under earthquake loading is an important factor affecting the performance of structures. Observations from past earthquakes have shown that piles in firm soils generally perform well, while the performance of piles in soft or liquefied ground can raise some questions. Centrifuge model tests were carried out at the National University of Singapore to investigate the response of pile-soil system under three different earthquake excitations. Some initial tests were done on kaolin clay beds to understand the pure clay behavior under repetitive earthquake shaking. Pile foundations comprising of solid steel, hollow steel and hollow steel pile filled with cement in-fill were then embedded in the kaolin clay beds to study the response of clay-pile system. Superstructural inertial loading on the foundation was modeled by fastening steel weight on top of the model raft. The model test results show that strain softening and stiffness degradation feature strongly in the behaviour of the clay. In uniform clay beds without piles, this is manifested as an increase in resonance periods of the surface response with level of shaking and with successive earthquakes. For the pile systems tested, the effect of the surrounding soft clay was primarily to impose an inertial loading onto the piles, thereby increasing the natural period of the piles over and above that of the pile foundation alone. There is also some evidence that the relative motion between piles and soil leads to aggravated softening of the soil around the pile, thereby lengthening its resonance period of the soil further. The centrifuge model tests were back-analyzed using the finite element code ABAQUS. The analysis shows that the simple non-linear hypoelastic soil model gave reasonably good agreement with the experimental observations. The engineering implication arising from this study so far is that, for the case of relatively short piles in soft clays, the ground surface motions may not be representative of the raft motion. Other than the very small earthquakes, the raft motion has a shorter resonance period than the surrounding soil.

Numerical Simulations of Dynamic Embedment During Pipe Laying on Soft Clay

2009 ◽  
Author(s):  
D. Wang ◽  
D. J. White ◽  
M. F. Randolph
Keyword(s):  
Soft Clay ◽  
Simple Approach ◽  
Published Data ◽  
Vertical Load ◽  
Centrifuge Model ◽  
Upper Limit ◽  
Different Types ◽  
Element Approach ◽  
Pipeline Design ◽  
Centrifuge Model Tests

Prediction of the as-laid embedment of a pipeline, which affects many aspects of pipeline design, is complicated by the dynamic motions that occur during the lay process. These motions cause pipelines to embed deeper than predicted based on static penetration models, as the seabed soils are both softened and physically displaced by the pipeline motion. This paper describes the results of 2D numerical analyses using a large displacement finite element approach aimed at quantifying pipeline embedment due to cyclic lateral motion at various fixed vertical load levels. The validity of the numerical results is first assessed by comparison with published data from centrifuge model tests in two different types of clay. A parametric study varying the normalized vertical load is then presented, which suggests a simple approach for estimating an upper limit to the dynamic embedment.

scholarly journals EVALUATION OF RAILWAY BALLAST LAYER CONSOLIDATION AFTER MAINTENANCE WORKS

2019 ◽  
Vol 59 (1) ◽  
pp. 77-87 ◽  
Author(s):  
Mykola Sysyn ◽  
Olga Nabochenko ◽  
Vitalii Kovalchuk ◽  
Ulf Gerber
Keyword(s):  
Statistical Analysis ◽  
Dynamic Analysis ◽  
Impulse Response ◽  
Complex Dynamic ◽  
Railway Ballast ◽  
Seismic Method ◽  
Automated Evaluation ◽  
Dynamic Interpretation ◽  
Different Types ◽  
Degree Of Consolidation

The results of the study of the ballast layer consolidation after the work of ballast-tamping machines of different types are given in the article. The existing methods of determining the degree of consolidation of the ballast layer are analysed. The seismic method was improved by means of a complex dynamic and kinematic interpretation of the impulse response. For the dynamic interpretation with the use of statistical analysis, the features are selected so that they correspond to the degree of consolidation of the ballast layer. On the basis of researches, a device and software were developed that allow an automated evaluation of the ballast layer consolidation based on the kinematic and dynamic analysis of the measured impulse response. The measurements of the degree of the ballast layer consolidation after an operation of ballast-consolidation machines in different sequences allowed establishing the efficiency of the consolidation and the feasibility of the machines’ application.

Solution charts for the consolidation of double soil layers

2005 ◽  
Vol 42 (3) ◽  
pp. 949-956 ◽  
Author(s):  
Guofu Zhu ◽  
Jian-Hua Yin
Keyword(s):  
Solution Procedure ◽  
Technical Note ◽  
Average Degree ◽  
Soil Layers ◽  
Consolidation Settlement ◽  
Degree Of Consolidation ◽  
Independent Parameters

This technical note presents solution charts for determining the average degree of consolidation of double soil layers for both one-way and two-way drainage. The influence of two newly introduced independent parameters on the average degree of consolidation is examined. The solution procedure is described clearly. When the compressibility, permeability, and thickness of the material making up each layer are given, the charts can be used to obtain the average degree of consolidation of the double soil layers for consolidation settlement calculations.Key words: consolidation, double soil layers, solution charts, drainage, settlement, soil.

Sign in / Sign up

Export Citation Format

Share Document