scholarly journals Dynamic Behavior and Constitutive Relationship of Mudstone Slip Zone of Landslide with Weak Interlayer

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Jingjing Zhou ◽  
Fasuo Zhao ◽  
Yanbo Zhu ◽  
Wenqi Dong ◽  
Ziguang He
Keyword(s):  
Elastic Modulus ◽  
Dynamic Behavior ◽  
Empirical Model ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Damping Ratio ◽  
Constitutive Relationship ◽  
Dynamic Elastic Modulus ◽  
Loading Frequency ◽  
Mountain Area

Sliding zone dynamics in the Qinling-Daba mountain area under different dynamic parameters have not been studied extensively. In this study, we investigated the dynamic behavior of the sliding zones of a high-steep rock landslide in the Qinling-Daba mountain area under the influence of dynamic stress amplitude and frequency and proposed an empirical model of the dynamic constitutive relationship. The dynamic behavior was studied based on a cyclic triaxial test system. The results indicated that an increase in the dynamic stress amplitude decreased the dynamic elastic modulus linearly, increased the damping ratio, and increased the axial strain exponentially. Among these properties, the elastic strain was found to be more sensitive to the increase in the dynamic stress amplitude than the plastic strain. As the loading frequency increased, the dynamic elastic modulus increased, whereas the damping ratio decreased. Furthermore, the proposed empirical model of the dynamic constitutive relationship between the vibration number and loading frequency based on the dynamic elastic modulus could satisfactorily describe the dynamic stress-strain relationships of the samples from test stability and failure zones. These findings are expected to make a significant contribution toward further revealing the sliding mechanism of such landslides.

scholarly journals Undrained Dynamic Behavior of Reinforced Subgrade under Long-Term Cyclic Loading

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Min Geng ◽  
Debin Wang ◽  
Peiyong Li
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Dynamic Behavior ◽  
Vibration Frequency ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Confining Pressure ◽  
Reinforced Soil ◽  
Dynamic Elastic Modulus

To study the dynamic behavior of reinforced subgrade, a series of undrained cyclic triaxial tests of reinforced soil (the specimen a height of 50 cm and a diameter of 20 cm) were performed in this paper. The specimens were tested by varying confining pressure, vibration frequency, dynamic stress amplitudes, and reinforced layers. Orthogonal experiment is a better way to optimize the process of experiment. Impact on dynamic behavior of the reinforced soil specimens is discussed through orthogonal design of experiments in four factors and three levels. This study has demonstrated that the order of dynamic elastic modulus of reinforced soil is influenced by dynamic stress amplitude, frequency, reinforced layer, and confining pressure within changing in factor level. The dynamic stress amplitude has great influence on the dynamic elastic modulus of reinforced soil. The bearing capacity and dynamic elastic modulus of reinforced subgrade decrease slightly with the increase of dynamic strain. Frequency has an influence on the dynamic elastic modulus. It is shown that the cumulative strain of reinforced soil is related to the vibration frequency. The test results also exemplify the reinforced subgrade restrict lateral displacement of subgrade and reduce settlement of subgrade under long-term cyclic loading.

The Deformation Characteristics of Soft Clay under Cyclic Loading

2012 ◽  
Vol 446-449 ◽  
pp. 1709-1712 ◽  
Author(s):  
Yong Zhang ◽  
Li Wan ◽  
Xiong Wei Li
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Elastic Strain ◽  
Dynamic Stress ◽  
Stress Amplitude ◽  
Soft Clay ◽  
Dynamic Elastic Modulus ◽  
Deformation Characteristics ◽  
Cycle Number ◽  
Critical Type

Through the undrained dynamic triaxial experiment, the deformation characteristics of saturated soft clay under cyclic loading are investigated. The cyclic loading was simplified as sine wave. It is found that under different dynamic stress, the deformation patterns of specimen in this experiment can be divided into three kinds, such as dense compressed, tensile break-up and shear failure type. In the process of vibration, the deformation forms of samples can also be divided into three types by dynamic stress amplitude, such as stable, destructive and critical type. The dynamic stress amplitude corresponding to the critical type is called critical dynamic stress. With the dynamic elastic strain increasing gradually, the dynamic elastic modulus decreases and rigidity softening occurs. Furthermore, dynamic elastic modulus and dynamic elastic strain curve decrease while the cyclic number is increasing. Finally, to establish the equation of the relationship between dynamic elastic modulus and dynamic elastic strain, the factor of cycle number should be considered.

scholarly journals Sandstone Dynamical Characteristics Influenced by Water-Rock Interaction of Bank Slope

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Huafeng Deng ◽  
Yinchai Zhang ◽  
Yongyan Zhi ◽  
Lingling Duan ◽  
Jianlin Li ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Dynamic Response ◽  
Stress Amplitude ◽  
Damping Ratio ◽  
Dynamic Parameter ◽  
Interaction Process ◽  
Dynamic Elastic Modulus ◽  
Rock Interaction ◽  
Bank Slope ◽  
Water Rock Interaction

During the long-term reservoir operation, the seismic capability and dynamic response characteristics of the bank slope are of great importance to its safety evaluation content. Aimed at typical bank slopes, considering reservoir water level fluctuation and soaking-air drying cyclic interaction, an experiment has been designed and conducted. In addition, the cyclic loading test with different stress amplitudes was carried out in different water-rock cycles. The laboratory results indicate that (1) during the immersion-air dry circulation process, the damping ratio and damping coefficient of sandstone gradually increased while the dynamic elastic modulus decreased. It is obvious that the dynamic elastic modulus of sandstone decreases dramatically during the immersion-air dry circulation process, especially in the first six periods. Also, its variation curve fits with the logarithmic curve. (2) When the cyclic load stress amplitude increases from 10 MPa to 35 MPa, the damping ratio and coefficient of the rock sample gradually decreased while dynamic elastic modulus increased. each dynamic parameter shows a more obvious variation trend when the stress amplitude is lower than 25 MPa. (3) During the water-rock interaction process, the closely knit microstructure of rock gradually becomes loose and porous, which resulted in the degradation of macroscopic physical and mechanical properties of sandstone. (4) In the analysis of the seismic response of the bank slope, the actual water-rock interaction process and the seismic level of the bank slope should be more considered. To find out further accurate reflection in the earthquake resistance and dynamic response of the bank slope, it is necessary to select the reasonable dynamic parameter to carry out seismic research.

scholarly journals Study on the Mechanical Properties of Chlorine Saline Soil under the Interaction of Multiple Factors

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Anhua Xu ◽  
Pengcheng Wang ◽  
Jianhong Fang
Keyword(s):  
Elastic Modulus ◽  
Moisture Content ◽  
Mechanical Characteristics ◽  
External Environment ◽  
Confining Pressure ◽  
Dynamic Elastic Modulus ◽  
Dynamic Strain ◽  
Saline Soils ◽  
Loading Frequency ◽  
Failure Strength

The distribution of chlorine saline soils is extensive in Haixi region of Qinghai Province in Northwest China. Its natural and geographical conditions are unique, and the external environment varies greatly. To study the effects of variable external environment on the mechanical characteristics of chlorine saline soils, a number of unconsolidated undrained (UU) dynamic triaxial tests under different confining pressure, moisture content, and loading frequency were carried out. The dynamic stress–dynamic strain, failure strength, dynamic elastic modulus, and parameter of shear strength were analyzed. The triaxial test results demonstrated that the stress–strain curves of the soil were strain-hardening. The failure strength and dynamic elastic modulus increased with the increasing of confining pressure; the law with moisture content and loading frequency were inconsistent. The dynamic cohesion and dynamic friction angle increased with the increasing of loading frequency, but decreased with the increasing of moisture content. Besides, the significance analysis theory was used to analyze the effect degree of different factors. It found that the effects of confining pressure, loading frequency, and the interaction between confining pressure and frequency on mechanical characteristics were significant, but the moisture content had less effect.

Dynamic Elastic Modulus and Damping Ratio of Unsaturated Red Clay

2019 ◽  
Vol 38 (1) ◽  
pp. 873-881
Author(s):  
Chang-xi Huang ◽  
Xing-hua Wang ◽  
Hao Zhou ◽  
Da-chao Qin
Keyword(s):  
Elastic Modulus ◽  
Damping Ratio ◽  
Dynamic Elastic Modulus ◽  
Red Clay

Study on Dynamic Elastic Modulus and Damping Ratio of Lime-Modified Expansive Soil

2019 ◽  
Vol 11 (7) ◽  
pp. 1052-1058
Author(s):  
Delei Yang ◽  
Yonghui Shang ◽  
Ping Xiang
Keyword(s):  
Elastic Modulus ◽  
Damping Ratio ◽  
Expansive Soil ◽  
Dynamic Elastic Modulus

Failure Characteristic of Granite under Cyclic Loading with Different Frequencies

2014 ◽  
Vol 638-640 ◽  
pp. 1967-1970
Author(s):  
Xiao Hui Ni
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Nuclear Power ◽  
Damping Ratio ◽  
Research Result ◽  
Testing Machine ◽  
Dynamic Elastic Modulus ◽  
Dynamic Strain ◽  
Response Analysis ◽  
Cyclic Frequency

The uniaxial cyclic fatigue tests on granite coming from the ChangJiang of Hainan nuclear power first-stage construction conventional island were done on the RMT-150B multi-function automatic rigid rock servo material testing machine. Stress amplitude of 10 MPa and sine wave cyclic loads with five different frequencies of 0.01, 0.02, 0.05, 0.1, 0.2, 0.5, and 1 Hz were adopted as dynamic disturbance. The law between cyclic frequency and dynamic stress-dynamic strain hysteretic curve, dynamic elastic modulus and damping ratio are researched. The results showed that the curves of strain and stress for loading and unloading are not superposition under cyclic loading, but hysteretic loops. When cyclic frequency changes between 0.01 and 1.0 Hz, the granite hysteretic loop area, dynamic elastic modulus and damping ratio are increased with frequency increasing. The research result offered great reference value to seismic response analysis and site safety evaluation of the changjiang nuclear power.

Study on the Cement-Improved Loess under the Vibratory Load by Dynamic Tests

2013 ◽  
Vol 838-841 ◽  
pp. 1302-1308 ◽  
Author(s):  
Jia Ding Wang ◽  
Shu Jun Peng ◽  
Wan Li Xie
Keyword(s):  
Elastic Modulus ◽  
Dynamic Characteristics ◽  
High Speed ◽  
Dynamic Deformation ◽  
Damping Ratio ◽  
Test Method ◽  
Dynamic Elastic Modulus ◽  
Dynamic Tests ◽  
Long Time ◽  
Orthogonal Test Method

In this paper based on the foundation construction of Datong Xian high-speed railway, a large number of test samples have been taken. The order and contribution rate of every experiment factor like cement commingle ratio, depths, water dipping conditions, compacting factor and vibration frequency on the dynamic characteristics of cement-improved loess such as dynamic elastic modulus, dynamic deformation, damping ratio by dynamic triaxial test, which orthogonal test method has been applied to. The dynamic load was calculated according to the train vibration attenuation rule of different depth. The dynamic characteristics of cement-improved loess such as dynamic deformation, dynamic elastic modulus, damping ratio were got form the dynamic tests of long time and large number of cycles. The results showed that with the increase of cement ratio, the dynamic characteristics of cement-improved loess are more better, there is no optimal ratio of cement.

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