Study on Stress of Closed Cut-Off Wall in Earth-Rock Dam Reinforcement under Different Engineering Conditions

2012 ◽  
Vol 594-597 ◽  
pp. 1969-1974 ◽  
Author(s):  
Jiang Lin Gao ◽  
Yun Xiang Chen
Keyword(s):  
Elastic Modulus ◽  
Stress State ◽  
Permeability Coefficient ◽  
Deformation Modulus ◽  
Dam Foundation ◽  
Filling Materials ◽  
The Earth ◽  
Coupled Numerical Model ◽  
Common Foundation ◽  
Wall Deformation

Closed concrete cut-off wall has been widely used in the reinforcement projects of earth-rock dam. However, the research on the cut-off wall was rare. In order to discuss the stress state of the wall under different engineering conditions, a coupled numerical model was established by considering coupled interaction, including contact between wall and dam, and coupling of stress and seepage. Taking the earth-rock dam which built on common foundation for example, the stress distribution of the wall and influencing law of different factors were mainly researched, including elastic modulus of the wall, deformation modulus of the dam filling materials, permeability coefficient of the dam foundation, etc. The conclusions had reference significance for the application and design and calculation method of concrete cut-off wall in the reinforcement projects of earth-rock dam.

scholarly journals Compression Characteristics of Solid Wastes as Backfill Materials

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Meng Li ◽  
Jixiong Zhang ◽  
Rui Gao
Keyword(s):  
Large Diameter ◽  
Testing Machine ◽  
Deformation Modulus ◽  
Compression Tests ◽  
Initial Portion ◽  
Filling Materials ◽  
Backfill Materials ◽  
Material Testing Machine ◽  
Compression Characteristics ◽  
The Relationship

A self-made large-diameter compression steel chamber and a SANS material testing machine were chosen to perform a series of compression tests in order to fully understand the compression characteristics of differently graded filling gangue samples. The relationship between the stress-deformation modulus and stress-compression degree was analyzed comparatively. The results showed that, during compression, the deformation modulus of gangue grew linearly with stress, the overall relationship between stress and compression degree was approximately nonlinear, and the deformation of gangue was rather large during the initial portion of the test. Gangue sample mixed with Talbot Formula provides the best deformation resistance capacity, followed by fully graded and single-graded gangue samples. For applications, with adjustment of the gradation of filling materials and optimal design of compacting equipment, surface subsidence may be better controlled.

Study on the Influence of Seepage Behavior of Dam Foundation during Wenchuan Earthquake

2011 ◽  
Vol 255-260 ◽  
pp. 3642-3645
Author(s):  
Kai Hua Zeng ◽  
Hai Yan Ju ◽  
Han Xing Peng
Keyword(s):  
Stress State ◽  
Wenchuan Earthquake ◽  
Groundwater Level ◽  
Tectonic Stress ◽  
Seepage Water ◽  
Dam Foundation ◽  
Strong Earthquakes ◽  
Main Effect ◽  
Small Decline ◽  
Shrinkage Property

Earthquake occurred on May 12, 2008 in Wenchuan, Sichuan Province, China, with magnitude of 8.0 and epicenter intensity of VI. Chencun hydropower station in southern Anhui Province has been shocked strongly during Wenchuan Earthquake, which stations 1,500 km away from Wenchuan. Tectonic stress caused by strong earthquakes inevitably led to the changes of stress state, groundwater level and pore pressure in the dam foundation. Seepage water level observation of the dam foundation had been encrypted immediately. According to the experimental data, it was conformed that significant effects were displayed on the dam foundation seepage because of Wenchuan earthquake, shunhe fault near dam sites was the main effect zone of earthquake tectonic stress, the downrange of groundwater depth was self-evident. As the existence of acrylamide curtain, swelling-shrinkage property of the acrylamide gel restricted the change of groundwater level and rock stress state in the dam foundation caused by seismic tectonic stress; the groundwater level behind the acrylamide curtain had a small decline, and recovering quickly.

scholarly journals Investigation of the Residual Stress State in an Epoxy Based Specimen

2015 ◽  
Vol 651-653 ◽  
pp. 375-380
Author(s):  
Ismet Baran ◽  
Johnny Jakobsen ◽  
Jens H. Andreasen ◽  
Remko Akkerman
Keyword(s):  
Elastic Modulus ◽  
Stress State ◽  
Residual Stresses ◽  
Process Model ◽  
Coefficient Of Thermal Expansion ◽  
Numerical Models ◽  
Mechanical Analysis ◽  
Biaxial Stress ◽  
Image Correlation ◽  
Drilling Process

Process induced residual stresses may play an important role under service loading conditions for fiber reinforced composite. They may initiate premature cracks and alter the internal stress level. Therefore, the developed numerical models have to be validated with the experimental observations. In the present work, the formation of the residual stresses/strains are captured from experimental measurements and numerical models. An epoxy/steel based sample configuration is considered which creates an in-plane biaxial stress state during curing of the resin. A hole drilling process with a diameter of 5 mm is subsequently applied to the specimen and the released strains after drilling are measured using the Digital Image Correlation (DIC) technique. The material characterization of the utilized epoxy material is obtained from the experimental tests such as differential scanning calorimetry (DSC) for the curing behavior, dynamic mechanical analysis (DMA) for the elastic modulus evolution during the process and a thermo-mechanical analysis (TMA) for the coefficient of thermal expansion (CTE) and curing shrinkage. A numerical process model is also developed by taking the constitutive material models, i.e. cure kinetics, elastic modulus, CTE, chemical shrinkage, etc. together with the drilling process using the finite element method. The measured and predicted in-plane residual strain states are compared for the epoxy/metal biaxial stress specimen.

Elastic-Plastic Finite Element Analysis on the Spillway of a Concrete Gravity Dam

2013 ◽  
Vol 295-298 ◽  
pp. 1870-1875
Author(s):  
Liang Cao ◽  
Hui Min Wang ◽  
Ji Yao ◽  
Shan Guang Qian ◽  
Chun Feng Tang
Keyword(s):  
Finite Element ◽  
Stress State ◽  
Limit State ◽  
Concrete Gravity Dam ◽  
Element Analysis ◽  
Full Account ◽  
Dam Foundation ◽  
Elastic Plastic ◽  
Geological Conditions ◽  
Sliding Stability

The 3-D finite element model of a concrete gravity dam’s spillway was established in this paper, and the elastic-plastic theory was applied, then the deformation and stress state of the dam under various working conditions were analyzed, it was prooved that the deformation and stress state of the dam were in normal condition. After solving the force of the dam foundation surface and taking full account of the complex geological conditions, the dam’s sliding stability was analyzed by capacity limit state design formula. The calculation results showed that, the stability parameter of the dam along foundation surface was bigger than 1.0, the dam’s sliding stability met the requirement.

scholarly journals Parametric Study of Sheet Pile Wall using ABAQUS

2021 ◽  
Vol 7 (1) ◽  
pp. 71-82
Author(s):  
Taku Muni ◽  
Dipika Devi ◽  
Sukumar Baishya
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Pressure Distribution ◽  
Earth Pressure ◽  
Sheet Pile ◽  
Passive Earth Pressure ◽  
Element Analysis ◽  
The Earth ◽  
Wall Deformation ◽  
Sheet Pile Wall

In the present study two-dimensional finite element analysis has been carried out on cantilever sheet pile wall using ABAQUS/Standard software to study the effect of different friction angles and its related parameters such as dilation angle, the interfacial friction coefficient between soil-wall on earth pressure distribution, and wall deformation. From the results obtained, it is found that there is a significant decrease in wall deformation with an increase in the angle of internal friction and its related parameters. The earth pressure results obtained from the finite element analysis shared a unique relationship with that of a conventional method. Both the results showed similar linear behavior up to a certain percentage of wall height and then changed drastically in lower portions of the wall. This trend of behavior is seen in both active as well as in passive earth pressure distribution for all the frictional angle. Hence, after comparing the differences that exist in the results for both methods, from the analysis a new relationship between the earth pressure coefficients from a conventional method and the finite element method has been developed for both active and passive earth pressure on either side of the sheet pile wall. This relationship so derived can be used to compute more reasonable earth pressure distributions for a sheet pile wall without carrying out a numerical analysis with a minimal time of computation. And also the earth pressure coefficient calculated from this governing equation can serve as a quick reference for any decision regarding the design of the sheet pile wall. Doi: 10.28991/cej-2021-03091638 Full Text: PDF

scholarly journals Experimental Study on the Mechanical Behavior of Yunnan Limestone in Natural and Saturated States

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Xutao Zhang ◽  
Mingyang Ren ◽  
Zhaobo Meng ◽  
Baoliang Zhang ◽  
Jinglong Li
Keyword(s):  
Elastic Modulus ◽  
Mechanical Behavior ◽  
Water Content ◽  
Failure Modes ◽  
Shear Failure ◽  
Mechanical Response ◽  
Deformation Modulus ◽  
Confining Pressure ◽  
Hyperbolic Function ◽  
Test Results

Rock material is a kind of mineral assemblage with complex structural heterogeneity, whose mechanical behavior is strongly affected by water or moisture content. In this work, we carried out a series of laboratory tests to investigate the mechanical response (e.g., deformation, strength, and failure characteristics) of Yunnan limestone in natural and saturated states. Our test results show that (1) after saturation, the stiffness and strength of Yunnan limestone degenerate considerably. Compared with the natural condition, the elastic modulus, deformation modulus, and tensile modulus decrease by about 30% on average, and uniaxial compressive strength and tensile strength also decrease by about 15% and 20%, respectively. While Poisson’s ratio is less affected by water content, it can be regarded as a constant; (2) the elastic modulus and deformation modulus of Yunnan limestone are significantly affected by confining pressure, and the relationship between them and confining pressure satisfies the law of hyperbolic function; (3) the peak strength envelope of Yunnan limestone has significant nonlinear characteristics, which can be well described by generalized Hoek-Brown strength criterion. However, the generalized Hoek-Brown criterion does not apply to the residual strength, which shows a linearly increasing trend with the increasing confining pressure; (4) the failure modes of Yunnan limestone are significantly dependent on confining pressure but insensitive to water content. With the increasing confining pressure, the failure modes of Yunnan limestone transform from splitting failure, tension-shear mixed failure, single inclined plane shear failure to Y-shaped or X-shaped conjugated shear failure. The test results can provide important experimental data for the establishment of the constitutive model of Yunnan limestone, which will contribute to obtain more reliable results for stability assessment of Xianglu Mountain Tunnel.

Elastic Modulus of Human Dental Enamel from Different Methods

2011 ◽  
Vol 1 (1) ◽  
pp. 39-48 ◽  
Author(s):  
Lars Raue ◽  
Helmut Klein ◽  
Christiane Hartmann
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Dental Enamel ◽  
High Importance ◽  
Experienced Reader ◽  
Dental Filling ◽  
Short Overview ◽  
Filling Materials

Knowing the elastic modulus of human dental enamel is of high importance since dental filling materials should posses equal mechanical properties as enamel itself. If this demand is not fulfilled, the interaction between filling and enamel is not equivalent, so that healthy enamel could be simply abrased during chewing. Hence it is astonishing that the literature shows a big variety of suggestions for the elastic modulus. This paper will give a short overview about some existing results (maybe not all) and tries to compare and evaluate them. The experiments have been done too, trying to make it more easy for the experienced reader to make up his own mind about the elastic modulus of human dental enamel.

Stress state in earthquake foci and the elastic stress field of the Earth

10.4095/8551 ◽  
1969 ◽  
Author(s):  
L M Balakina ◽  
L A Misharina ◽  
E I Shirokova ◽  
A V Vvedenskaya
Keyword(s):  
Stress State ◽  
Stress Field ◽  
Elastic Stress ◽  
The Earth ◽  
Elastic Stress Field

scholarly journals Experimental Study on the Reinforcement Mechanism of Segmented Split Grouting in a Soft Filling Medium

Processes ◽  
2018 ◽  
Vol 6 (8) ◽  
pp. 131 ◽  
Author(s):  
Zhipeng Li ◽  
Shucai Li ◽  
Haojie Liu ◽  
Qingsong Zhang ◽  
Yanan Liu
Keyword(s):  
Elastic Modulus ◽  
Permeability Coefficient ◽  
Three Dimensional ◽  
Weighted Average ◽  
Quantitative Relationship ◽  
Uniaxial Compression Test ◽  
Distribution Characteristics ◽  
Reinforcement Mechanism ◽  
Before And After ◽  
Grouting Reinforcement

Subsection split grouting technology can effectively improve the grouting efficiency and homogeneity of grouting in a target reinforcement area. It is therefore necessary to clarify the reinforcement mechanism and characteristics of the soft filling medium under the condition of split grouting. A three-dimensional grouting simulation test of segmented split grouting in a soft filling medium was conducted. The distribution characteristics and thicknesses of the grouting veins were obtained under the condition of segmented grouting. The mechanical mechanism of segmented split grouting reinforcement, based on the distribution characteristics of different grouting veins, was revealed. After grouting, a uniaxial compression test and an indoor permeation test were conducted. Based on the method of the region-weighted average, the corresponding permeability coefficient and the elastic modulus of each splitting-compaction region were obtained. The quantitative relationship between the mechanical properties and the impermeability of the soft filling medium before and after grouting was established. The results revealed that three different types of veins were formed as the distance from the grouting holes increased; namely, skeleton veins, cross-grid grouting veins, and parallel dispersed grouting veins. The thicknesses of the grouting veins decreased gradually, whereas the number of grouting veins increased. Moreover, the strikes of the grouting vein exhibited increased randomness. The reinforcement effect of segmental split grouting on soft filling media was mainly confirmed by the skeleton support and compaction. The elastic modulus of the grouting reinforcement solid increased on average by a factor that was greater than 100, and the permeability coefficient decreased on average by a factor that was greater than 40 in the direction of the parallel grouting vein with the most impermeable solid. The research results may be helpful in the investigation of the split grouting reinforcement mechanism under the condition of segmented grouting.

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