scholarly journals Study on Dynamic Response Characteristics and Damage Mechanism of Tunnel Lining at Entrance of Shallow Bias Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lin Li ◽  
Xiaodan Guo ◽  
Zuyin Zou ◽  
Zhanyuan Zhu ◽  
Zihong Guo ◽  
...  

The structural damage of the lining structure at the entrance of a tunnel is the most common instability problem. The instability problem may cause dynamic effects such as earthquakes and blasting. Based on the seismic damage data collected from previous major earthquakes at the entrance of shallow-buried tunnel, the shaking table test and numerical simulation are used to analyze dynamic response characteristics and damage evolution characteristics of the tunnel in the shallow-buried hole at 30°. The study revealed the stress characteristics of tunnel lining and the mechanism of structural damage under earthquake excitation. The research results show that the biased tunnel (30°) is susceptible to damage on the unsymmetrical loading side, the biased ground surface leads to acceleration, and high speed also significantly increases the effect. The biased side leg of the tunnel lining cross section is a location with a large internal force distribution. The biased tunnel has a relatively unfavorable internal force value distribution and a larger peak, and the peak at the larger bias side has the largest peak value. The skewback and spandrel portion of the biased tunnel lining load are more likely to be damaged.

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Kan Han ◽  
Chunxiao Xue

In order to reduce the damage of liquefaction of aeolian sand along the Sichuan-Tibet railway, the dynamic response characteristics of saturated aeolian sand in the study area were discussed by using shaking table test. The results show that the macroscopic characteristics of saturated aeolian sand in the study area are subsidence, water flow and fracture. The displacement time history shows that the surface displacement increases with increasing the input ground motion acceleration. When the acceleration is small (0.1g), the vibration in the soil layer has an obvious tendency to enlarge continuously from bottom to top. With the increase of the acceleration (0.2g), the amplification trend basically disappeared. When the acceleration increases to 0.3g, the ground motion increases first and then decreases.


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianyu Zhang ◽  
Peng Liu ◽  
Liyun Fan ◽  
Yajie Deng

A 3D numerical simulation model of high-speed solenoid valve (HSV) for electronic control fuel injection system (ECFIS) has been developed. The model has been validated experimentally with acceptable maximum errors of 2% and 8.7% in closure response time and open response time, respectively. Effect of assembly parameters such as residual air gap, maximum lift of valve stem, mass of the moving parts, spring stiffness, and spring pretightening force on dynamic response characteristics of HSV has been analyzed in detail using the simulation model, and influence rules of various parameters on dynamic response characteristics have been established. Moreover, the correlation between interaction factors of main influence factors and dynamic response characteristics of HSV has also been analyzed. It is concluded that residual air gap, maximum lift of the valve stem, and spring pretightening force are the main influencing factors on dynamic response characteristics of HSV, and there are obvious interaction effects between them; when two or three of these main influencing factors are adjusted at the same time, the interaction effects should be considered.


2011 ◽  
Vol 311-313 ◽  
pp. 1398-1403
Author(s):  
Ying Cai Yuan ◽  
Yan Li ◽  
Yi Ming Wang

In high speed, the web press’s fold mechanism appears nonlinear dynamic response characteristics, which seriously affect the fold system’s stability and precision. The clearance and roller’s deformation are the main factors to cause the nonlinear dynamic response. To study the influence of clearance and roller’s deformation, the hypothesis of rigid role and spring combination is put forward. Based on the hypothesis, the dynamics model of fold system with clearance is established by kinematics and dynamics analysis. Through the dynamics model of fold system, the situation of pair clearance and roller’s deformation can be obtained, and the influence to the dynamic performance of fold system can be easily got.


2020 ◽  
Vol 13 (18) ◽  
Author(s):  
Jiaxu Jin ◽  
Qianshen Ding ◽  
Hongzhi Cui ◽  
Pingyi Zhang ◽  
Xiaochun Xiao ◽  
...  

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1375
Author(s):  
Duan Zhu ◽  
Zhende Zhu ◽  
Cong Zhang ◽  
Xinghua Xie

Fault-crossing tunnels are often severely damaged under seismic dynamics. Study of the dynamic response characteristics of tunnels crossing faults is thus of great engineering significance. Here, the Xianglushan Tunnel of the Central Yunnan Water Diversion Project was studied. A shaking table experimental device was used, and four sets of dynamic model tests of deep-buried tunnels with different fault inclination angles were conducted. Test schemes of model similarity ratio, similar material selection, model box design, and sine wave loading were introduced. The acceleration and strain data of the tunnel lining were monitored. Analysis of the acceleration data showed that when the input PGA was 0.6 g, compared with the ordinary tunnel, the acceleration increases by 117% when the inclination angle was 75°, 127% when the inclination angle was 45°, and 144% when the inclination angle was 30°. This indicates that the dynamic response of the cross-fault tunnel structure was stronger than that of the ordinary tunnel, and the effect was more obvious as the fault dip angle decreased. Analysis of the strain data showed that the strain response of the fault-crossing tunnels was more sensitive to the fault dip. The peak strain and increase in fault-crossing tunnels were much larger than those of ordinary tunnels, and smaller fault dips led to larger increases in the strain peak; consequently, the tunnel would reach the ultimate strain and break down when the input PGA was smaller. Generally, the influence of fault inclination on the dynamic response of the tunnel lining should receive increased consideration in the seismic design of tunnels.


2021 ◽  
Author(s):  
Xueliang Jiang ◽  
Yonghui Qian ◽  
Jiqi Zhang ◽  
Yong Liu ◽  
RiWe Deng ◽  
...  

Abstract Through the shaking table test, Wenchuan wave (WC) was used as the excitation wave of the shaking table test. The vibration was excited in three directions: horizontal (x), vertical (z), and horizontal and vertical (xz) and the dynamic response characteristics of rock slopes was studied. The results show:(1) The acceleration amplification factor of each measuring point of the slope shows a nonlinear increasing trend with the increase of the slope height.The slope changes the frequency spectrum of the loaded seismic wave.The slope has a filtering effect on the high frequency band of the seismic wave.(2) Under the unidirectional cyclic loading of Wenchuan wave, the slope acceleration amplification factor increases with the increase of the peak value of the seismic wave. Under the bi-directional excitation of Wenchuan wave, the slope acceleration amplification coefficient generally decreases with the increase of the peak value of the seismic wave.The slope acceleration amplification factor presents the characteristics of first increasing and then decreasing with the increase of the relative height of the slope.(3) The dynamic displacement response characteristics of the tunnel slope with double-arch tunnel are mainly affected by the seismic wave in the same direction and the peak value of the dynamic displacement response increases with the increase of the seismic wave peak value.(4) The peak dynamic displacement response of the double-arch tunnel slope shows a non-linear change trend with the increase of slope height. The dynamic displacement peak growth rate is slower below the rock interface and the dynamic displacement peak increases rapidly above the interface and Maximum displacement occurred at the top of the slope.


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