Parameter Identification and Numerical Analysis of Shaking Table Tests on Liquefiable Soil-Structure-Interaction

2010 ◽  
Vol 163-167 ◽  
pp. 4048-4057
Author(s):  
Pei Zhen Li ◽  
Da Ming Zeng ◽  
Sheng Long Cui ◽  
Xi Lin Lu
Keyword(s):  
Numerical Simulation ◽  
Parameter Identification ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shaking Table ◽  
Soil Parameters ◽  
Shaking Table Tests ◽  
Structure Interaction ◽  
Liquefiable Soil

Using the parameter identification method of analysis on the test records of soil acceleration and pore water pressure from the shaking table tests for dynamic liquefiable soil-pile-structure interaction system, the dynamic properties of soil are obtained. Based on the recognized soil parameters, numerical simulation of liquefiable soil-pile-structure interaction test has been carried out. The results of the comparision of acceleration response and pore water pressure obtained from numerical simulation and tests show that the rule drawn from the numerical simulation is agreed well with those from the tests, though there are some disparities in quantity. So the reliability of parameter identification and numerical simulation technology in shaking table tests is validated. The result in this dissertation can be referred for future similar research.

Shaking table tests to parametrically evaluate post-shaking settlements and pore water pressure build-up in marine sands

2021 ◽  
Vol 14 (8) ◽  
Author(s):  
Ali Ghorbani ◽  
Afshar Nemati Mersa ◽  
Mehdi Veiskarami ◽  
Naser Hamidzadeh ◽  
Hadi Hasanzadehshooiili
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Shaking Table ◽  
Shaking Table Tests

scholarly journals Seismic Performance Evaluation of Agricultural Reservoir Embankment through Shaking Table Tests

2021 ◽  
Vol 21 (3) ◽  
pp. 151-161
Author(s):  
Younghak Lee ◽  
Junghyun Ryu ◽  
Bora Yoon ◽  
Joon Heo ◽  
Dalwon Lee
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Pressure Ratio ◽  
Horizontal Displacement ◽  
National Standards ◽  
Shaking Table ◽  
Seepage Water ◽  
Shaking Table Tests ◽  
Experimental Conditions

In this study, shaking table tests were performed to compare and analyze the acceleration response, displacement behavior, and pore-water pressure behavior of reservoirs with parapets installed to prevent overtopping of deteriorative homogeneous reservoirs. During the shaking table tests, the experimental conditions were divided into four cases considering the range and magnitude of seismic acceleration according to national standards. The vibration-type waveform (Gongen) and shock-type waveform (Minogawa) were applied as input waveforms. The acceleration amplification ratios of both vibration- and shock-wave types were the largest in the dam crest, and the amplification ratio decreased as the design earthquake acceleration increased. In addition, the horizontal displacement was maximum on the upstream slope, owing to the influence of seepage water, and the vertical displacement was maximum on the dam crest, owing to the self-weight effect of the parapet structure. A comparison of the waveform results indicates that the vibration-type waveform may exhibit a more significant effect on the embankment zone displacement than the shock-type waveform. However, when the safety standards for the horizontal displacement, settlement ratio, and excess pore-water pressure ratio were applied, the embankment was stable within the allowable range in both the shock-type and vibration-type waveforms. Therefore, the parapet structure is expected to influence the overflow resistance and stability of embankments positively.

scholarly journals Effect of Seismic Loading on Variation of Pore Water Pressure During Pile Pull-Out Tests in Sandy Soils

2021 ◽  
Vol 27 (12) ◽  
pp. 1-12
Author(s):  
Haider N. Abdul Hussein ◽  
Qassun S. Mohammed Shafiqu ◽  
Zeyad S. M. Khaled
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Seismic Loading ◽  
Shaking Table ◽  
Dense Sand ◽  
Pressure Transducers ◽  
Pull Out ◽  
Pullout Tests ◽  
Pile Model

Experimental model was done for pile model of L / D = 25 installed into a laminar shear box contains different saturation soil densities (loose and dense sand) to evaluate the variation of pore water pressure before and after apply seismic loading. Two pore water pressure transducers placed at position near the middle and bottom of pile model to evaluate the pore water pressure during pullout tests. Seismic loading applied by uniaxial shaking table device, while the pullout tests were conducted through pullout device. The results of changing pore water pressure showed that the variation of pore water pressure near the bottom of pile is more than variation near the middle of pile in all tests. The variation of pore water pressure after apply seismic loading is more than the variation before apply seismic loading near the middle of pile and near the bottom of pile and in loose and dense sand. Variation of pore water pressure after apply seismic loading and uplift force is less than the variation after apply seismic loading in loose sand at middle and bottom of pile.

scholarly journals Numerical Evaluation of The Nonlinear Behavior of Soil-Pile Interaction Under The Effect of Coupled Static-Dynamic Loads

2021 ◽  
Author(s):  
Duaa Al-Jeznawi ◽  
ISMACAHYADI Mohamed Jais ◽  
Bushra S. Albusoda
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Three Dimensional ◽  
Ground Surface ◽  
Frictional Resistance ◽  
Saturated Soil ◽  
Shaking Table ◽  
Physical Models ◽  
Soil Layers

Abstract Liquefaction of saturated soil layers is one of the most common causes of structural failure during earthquakes. Liquefaction occurs as a result of increasing pore water pressure, whereby the rise in water pressure occurs due to unexpected change in stress state under short-term loading, i.e., shaking during an earthquake. Thus, general failure occurs when the soil softens and eliminates its stiffness against the uplift pressure from the stability of the subsurface structure. In this case, the condition of soil strata is considered undrained because there is not enough time for the excess pore water pressure to dissipate when a sudden load is applied. To represent the non-linear characteristics of saturated sand under seismic motions in Kobe and Ali Algharbi earthquakes, the computational model was simulated using the UBCSAND model. The current study was carried out by adopting three-dimensional-based finite element models that were evaluated by shaking table tests of a single pile model erected in the saturated soil layers. The experimental data were utilized to estimate the liquefaction and seismicity of soil deposits. According to the results obtained from the physical models and simulations, this proposed model accurately simulates the liquefaction phenomenon and soil-pile response. However, there are some differences between the experiment and the computational analyses. Nonetheless, the results showed good agreement with the general trend in terms of deformation, acceleration, and liquefaction ratio. Moreover, the displacement of liquefied soil around the pile was captured by the directions of vectors generated by numerical analysis, which resembled a worldwide circular flow pattern. The results revealed that during the dynamic excitation, increased pore water pressure and subsequent liquefaction caused a significant reduction in pile frictional resistance. Despite this, positive frictional resistance was noticed through the loose sand layer (near the ground surface) until the soil softened completely. It is worth mentioning that the pile exhibited excessive settlement which may attribute to the considerable reduction, in the end, bearing forces which in turn mobilizing extra end resistance.

scholarly journals Physical Model Test for Soft Soil With or Without Prefabricated Vertical Drain with Loading

2018 ◽  
Vol 4 (8) ◽  
pp. 1809
Author(s):  
Dao Huu Do ◽  
Nguyen Thi Phuong Khue ◽  
Phan Khac Hai
Keyword(s):  
Numerical Simulation ◽  
Physical Model ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Soft Soil ◽  
Physical Model Test ◽  
Soil Parameters ◽  
Vertical Drain ◽  
Prefabricated Vertical Drain ◽  
Before And After

The paper builds a physical model of testing in the laboratory with the parametric tempered glass box 0.5  0.5 1.2 m (length  width  depth) containing saturated clay to study the settlement and consolidation when loading increased gradually over time. The research covers herein to present the monitoring of settlement and pore water pressure, settlement calculation, numerical simulation using PLAXIS software V8.2 based on the results of soil physical and mechanical tests before and after loading in case of having or not prefabricated vertical drain (PVD). In case of no PVD, the calculation and numerical simulation using the soil parameters before loading have the differential settlement from the monitoring data, approximately 3.86 mm (10.45%), 0.41 mm (1.11%) respectively. Meanwhile, the deviation in the case using data after loading is about 2.29 mm (6.20%), 0.21 mm (0.56%) respectively. In case of PVD, the calculation and numerical simulation with the testing result of before loading deviation from the settlement monitoring by subsidence meter is 2.91 mm (7.88%), 44.42 mm (120.28%), calculation and simulation with the testing result of after loading deviation is 0.80 mm (2.17%), 1.26 mm (3.41%). In the case of having PVD, the difference in calculation, subsidence observation, and numerical simulation between the mechanical properties before and after loading is significant, when using the mechanical data after loading then the results are quite close to the subsidence of observation and simulation rather than before loading. 

Time Effect of the Pile Bearing Capacity in Dredger Fill

2013 ◽  
Vol 639-640 ◽  
pp. 630-638
Author(s):  
Hua Yang Lei ◽  
Qian Qian Lv
Keyword(s):  
Numerical Simulation ◽  
Bearing Capacity ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Ultimate Bearing Capacity ◽  
Time Effect ◽  
Second Phase ◽  
Excess Pore Water Pressure ◽  
Excess Pore

The dissipating of pore water pressure caused by pile sinking is one of the main factors resulting in time effect of ultimate bearing capacity of pile.The pore water pressure is monitored at each observing point during pile sinking and after that. With the pore pressure plan embedded in advance, by means of spot test in the process of pile sinking, under this geological conditions of the pile foundation by referring to the second phase project of the free port logistics processing zone in Dongjiang, Tianjin.The change law of the distribution and dissipation of excess pore water pressure with time, depth, radial distance and permeability coefficient of soil was also discussed. It’s found that the excess pore water pressure attenuates approximately linearly with the increase of the distance from the pile heart and the scope influenced is around 10d. As the numerical simulation accord with the test results effectively, promote the results then get the change rule of pile bearing capacity with time.The formula of pile bearing capacity about time effect in dredge fill was deduced for engineering reference.The effect of soil internal friction angle on the ultimate bearing capacity of pile was discussed. Numerical simulation shows that the ultimate bearing capacity of pipe pile increases over time and keeps stable after 20d.The ultimate limit bearing capacity is 1473kN with increase of 12.3%, the time when it reaches the stable state is in accord with the excess pore water pressure dissipation monitored at each observing point. The larger the internal frictional angle of soil becomes, the more the ultimate bearing capacity is. The angle exceeding 20°,the bearing capacity would not increase as internal frictional angle of soil increases.

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