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.

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

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.

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.

Test Research on Single Point Impact of a Liquid Foundation

2011 ◽  
Vol 415-417 ◽  
pp. 869-874
Author(s):  
Yun Cao
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Single Point ◽  
Horizontal Displacement ◽  
Dynamic Compaction ◽  
Before And After ◽  
Engineering Parameters ◽  
Ground Heave ◽  
The Relationship

Dynamic compaction is a widely used method for subgrade treatment due to its merit. This article presented example of dynamic compaction test in a liquid foundation project and investigated the relationship between settlement, ground heave and drop counts, the relationship between horizontal displacement and depth of soil, the relationship between drop counts, depth, horizontal displacement and pore water pressure, and the relation curve of pore water pressure and time during single point impact test. According to the conclusion before and after the testing, some appropriate engineering parameters were obtained and some advices were put forward.

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 Finite Element Analysis of Vertical and Horizontal Drainage Structures under Vacuum Combined Surcharge Preloading

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Daqing Wang ◽  
Dong Wei ◽  
Guoyi Lin ◽  
Jiannan Zheng ◽  
Zhiting Tang ◽  
...  
Keyword(s):  
Finite Element ◽  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Horizontal Displacement ◽  
Reinforcement Effect ◽  
Vacuum Suction ◽  
Prefabricated Vertical Drains ◽  
Surcharge Preloading ◽  
Prefabricated Vertical Drain

Combined vacuum and surcharge preloading has gradually been widely used because of its advantages of low cost, green environmental protection, and good treatment effect. The conventional prefabricated vertical drain presents obvious defects in vacuum preloading treatment, such as obvious silting, serious bending of the drainage board, large attenuation of vacuum degree of drainage board along the depth, long construction period, and so on, which affect the final reinforcement effect. In this paper, the MIDAS finite element simulation of combined vacuum and surcharge preloading of prefabricated vertical drains (PVDs) and prefabricated horizontal drains (PHDs) is established through the comparative experiment of the engineering field. The comparative experimental study is carried out from the aspects of the vertical settlement, horizontal displacement, and pore water pressure. The results show that under combined vacuum and surcharge preloading, the consolidation effect of soft soil with PHDs is better than that with PVDs. When PHDs are used, the vertical settlement increases by 7.2% compared with PVDs; the horizontal displacement is larger; and the pore water pressure dissipates faster. This is because when the PHDs are adopted, the consolidation direction of the soil is consistent with the direction of the vacuum suction, which is mainly caused by vertical settlement. With the consolidation, the spacing between PHDs is gradually shortened, and the drainage distance is reduced, which can effectively reduce the consolidation time and improve the reinforcement effect of the soil. In addition, the PHDs can move downward uniformly with the soil during the consolidation process and have almost no bending deformation, which makes the vacuum transfer more uniform and effective.

Numerical Analysis of Grouting and Blocking of Deep Large Section Shaft at Working Face

2012 ◽  
Vol 157-158 ◽  
pp. 865-869
Author(s):  
Ji Ming Zhu ◽  
Wen Quan Zhang ◽  
Hai Ling Yu ◽  
Xiang Lan Liu
Keyword(s):  
Pore Water ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Water Channel ◽  
Seepage Flow ◽  
Water Inflow ◽  
Seepage Water ◽  
Large Section ◽  
Working Face ◽  
Water Block

To estimate the effect of deep large section Shaft Face Grouting for water block, the mathematical model is obtained according to the seepage theory. The numerical model for calculation is established by the program ABAQUS. The laws of change of pore water pressure, the effect area of dewatering, the velocity of seepage, water inflow of shaft working face before and after grouting is obtained by numerical simulation. It is shown that the grouting can effectively plug water channel of cracked surrounding rock, and prevent the pore water pressure lowering range to be larger. The working face seepage flow velocity was significantly reduced. The water inflow is decreased significantly. The safety of the shaft construction and the stability structure of shaft lining and upper strata are ensured by grouting. The numbers of grout stop and grouting construction can be largely reduced. The economic benefit is obvious. The scientific reference is provided for deep large section Shaft Face Grouting for water block.

Sign in / Sign up

Export Citation Format

Share Document