scholarly journals Experimental Study on Seismic Performance of Prefabricated Utility Tunnel

2019 ◽  
Vol 2019 ◽  
pp. 1-14
Author(s):  
Xu Duan ◽  
Qi Dong ◽  
Wanjun Ye
Keyword(s):  
Seismic Performance ◽  
Boundary Effect ◽  
Public Utility ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Soil Pressure ◽  
Scaled Model ◽  
Sensor Arrangement ◽  
Utility Tunnel

Utility tunnel is a kind of underground tunnel structure that carries more than two types of public utility lines, and the utility tunnels built by the prefabricated method have been adopted in many modern cities due to their easy maintenance and environmental protection capabilities. However, knowledge about the seismic performance of the prefabricated utility tunnel and pipelines inside is quite limited. In this paper, a prefabricated utility tunnel newly built in Xi’an, China, is taken as the prototype; a series of shaking table tests are conducted to investigate the seismic performance of the prefabricated utility tunnel in loess foundation, using El Centro earthquake wave as the input loading. Details of the experimental setup focus on the design of the soil container, scaled model (1 : 10), sensor arrangement, and test cases. Dynamic responses including evaluation of boundary effect, the amplification factor of the ground and structure, distribution of soil pressure, characteristics of predominant frequencies, and the damage phenomena are analyzed. Dynamic strain obtained by Fiber Bragg Grating sensors releases the critical positions of the prefabricated utility tunnel during the earthquake. Moreover, the dynamic responses of the pipelines contained in the utility tunnel are also analyzed. From aforementioned results, the seismic performance of the prefabricated utility tunnel has been revealed. The results will provide a reference for the seismic design of prefabricated utility tunnels.

Seismic Performance Evaluation of a High-Rise Building with Lapping Transfer Columns by Shaking Table Tests

2010 ◽  
Vol 163-167 ◽  
pp. 1281-1285
Author(s):  
Bin Wang ◽  
Huan Jun Jiang ◽  
Jian Bao Li ◽  
Wen Sheng Lu ◽  
Xi Lin Lu
Keyword(s):  
Seismic Performance ◽  
Shaking Table Test ◽  
Dynamic Properties ◽  
Shaking Table ◽  
Vertical Force ◽  
Scaled Model ◽  
Seismic Performance Evaluation ◽  
High Rise ◽  
High Rise Building ◽  
Global And Local

The reinforced concrete (RC) frame-tube structure considered in the study has two towers with lapping transfer columns. The lapping transfer columns, considering aesthetic requirement in elevation, lead to a complex vertical force transfer system. The large irregularity in elevation, according to Chinese code, necessitates a detailed study. A 1/15-scaled model of the high-rise building was tested on a shaking table to evaluate its seismic performance. The model was subjected to earthquake inputs representing frequent, basic, rare, and extremly rare earthquakes. The results of shaking table test in terms of the global and local responses as well as the dynamic properties are presented. The tests demonstrate that the designed structural system satisfies the pre-defined performance objectives and the lapping transfer columns have good seismic peformance. To better control seismic damages of the building, some suggestions for improving the design of this structure are also put forward at last.

scholarly journals Seismic Performance of Masonry Cross Vaults through Shaking Table Testing on a Scaled Model

2021 ◽  
Author(s):  
N. Bianchini ◽  
N. Mendes ◽  
P. Candeias ◽  
M. Rossi ◽  
C. Calderini ◽  
...  
Keyword(s):  
Seismic Performance ◽  
Shaking Table ◽  
Scaled Model ◽  
Shaking Table Testing

Dynamic Response in ALF Aggregate Base Asphalt Pavement

2011 ◽  
Vol 97-98 ◽  
pp. 40-44 ◽  
Author(s):  
Chuan Yi Zhuang ◽  
Ai Qin Shen ◽  
Lin Wang
Keyword(s):  
Dynamic Response ◽  
Compressive Stress ◽  
Asphalt Pavement ◽  
Compressive Strain ◽  
Full Scale ◽  
Dynamic Responses ◽  
Traffic Load ◽  
Dynamic Strain ◽  
Strain Response ◽  
Soil Pressure

In order to evaluate pavement dynamic responses accurately under truck loading, the full-scale asphalt pavement accelerated loading facility (ALF) was used. 10 strain gauges and 2 soil pressure cells were installed; temperature sensors were also installed in the different depth of the HMA layer. Pavement response was measured under real traffic load with ALF. The measured pavement responses are compared between the pavement sections to evaluate the effects of various experimental factors, such as axle load, speed, et al. Dynamic strain at the bottom of HMA layer and vertical compressive stress on the top of the subgrade were examined in the full-scale testing road, the regression models between dynamic response and axle load, dynamic response and speed were put forward respectively. Studies show that there is not only tensile strain but also compressive strain in the dynamic response, and the strain response is in the station of tension and compression alternation. Under the intermediate temperature, the strain response at the bottom of the asphalt layer is increased linearly with the increase of axle load and the vertical compressive stresses at the top of the subgrade is also increased with the increase of axle load. Speed has a great effect on strain response at the bottom of HMA layer, and has little effect on vertical compressive stress, it affects the loading duration of stress only. The destroy for the pavement by low speed and heavy load is more serious than that is normal.

scholarly journals Shaking Table Tests for Seismic Response of Oblique Overlapped Tunnel

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Hao Lei ◽  
Honggang Wu ◽  
Tianwen Lai
Keyword(s):  
Seismic Response ◽  
Cross Section ◽  
Slope Failure ◽  
Response Spectrum ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Seismic Load ◽  
Shaking Table Tests ◽  
The Cross

To study the dynamic response and spectrum characteristics of the three-dimensional crossing tunnel under the action of seismic load, we established a 1/50 downscale model based on a typical of the oblique overlapped tunnel and conducted a series of shaking table tests. Through examining the recorded dynamic responses (acceleration and dynamic strain measured at different locations in model tunnels), we found that the seismic response of the crown was the largest at the central section, and the invert of the tunnels was exactly opposite to the crown, which presented a “parabolic” distribution, and we inferred that the damage within the model may be mainly concentrated on the crown of the tunnels. Additionally, the dynamic strain showed obvious nonlinear and nonstationary characteristics under the action of different degrees of seismic intensities. Different from a single tunnel, the acceleration superposition effect appears in the cross section of two tunnels because of the spatial effect of overlapping tunnels, resulting in the obvious seismic response in the cross section. Meanwhile, we also found that the 1st dominant frequency (0.1–6.26 Hz) seismic wave played a leading role in the process of tunnel slope failure. Furthermore, the analysis of the acceleration response spectrum also showed that the surrounding rock mass has an amplification effect on low-frequency seismic waves. These results help us better understand the features of the dynamic responses and also provide evidence to reinforce the overlapped tunnels against earthquakes.

scholarly journals Seismic Performance of Deposit Slopes With Underlying Bedrock Before and After Reinforcement by Stabilising Piles

2021 ◽  
Author(s):  
Zhiliang Sun ◽  
Kong Lingwei ◽  
Bai Wei ◽  
Wang Yong
Keyword(s):  
Seismic Performance ◽  
Seismic Waves ◽  
Bending Moment ◽  
Resultant Force ◽  
Shaking Table ◽  
Slope Instability ◽  
Dynamic Responses ◽  
Seismic Excitation ◽  
Ground Acceleration ◽  
Response Characteristics

Abstract The seismic performance of stabilising piles used to reinforce underlying bedrock in a deposit slope is a complex soil-structure interaction problem, on which there is limited design guidance on the optimum use of a single row of rock-socketed piles to reinforce such slopes. Two centrifuge shaking-table model tests at a geometric scale of 1:50 were conducted to ascertain the dynamic responses of the underlying bedrock deposit slopes without and with the use of stabilising piles during an earthquake. Multi-stage seismic waves with various peak accelerations were applied from the bottom of each model. Under seismic excitation, the differences in the response accelerations between the deposit and bedrock increase significantly with the increase in amplitude of the input seismic waves. The two are prone to uncoordinated movement, which leads to slope instability. Setting stabilising piles reduces the crest settlement and angular deformation and changes the natural frequency of the slope crest. The presence of the rock-socketed stabilising piles can bridge the uncoordinated movement of the bedrock and the overlying deposit to some extent. According to the mobilised pile bending moment, shear force, lateral pile-soil load distribution, and pile displacement, the dynamic response characteristics of stabilising piles under continuous multi-level seismic excitation were analysed. The resultant force arising from a distributed load increment on the piles caused by an earthquake is mainly concentrated in the upper part (the point of action of the resultant force is 1.54m below the slope surface). With increases in the peak ground acceleration (PGA) of the input motion, the resistance of the bedrock in front of the stabilising piles increases; moreover, with the increase of PGA, the peak resistance under the bedrock surface of the stabilising piles gradually moves downwards. This finding indicates that the strong seismic motion significantly changes the embedded working state of the stabilising pile.

scholarly journals Experimental Study on Seismic Response of a Large-Span and Column-Free Subway Station in Composite Strata

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Tingjin Liu ◽  
Siyuan Zheng ◽  
Xinwei Tang ◽  
Weixing Xu
Keyword(s):  
Seismic Response ◽  
Shaking Table Test ◽  
Boundary Effect ◽  
Soft Clay ◽  
Lateral Wall ◽  
Shaking Table ◽  
Subway Station ◽  
Model Structure ◽  
Soil Pressure ◽  
Large Span

In this paper, a shaking table test was conducted to investigate the seismic response of the large-span and column-free subway station in the upper-soft and lower-hard strata. The acceleration of the structure and the soil, the dynamic soil pressure, and the strain response of the subway station were obtained and analyzed. The results demonstrate the reasonable test design as the boundary effect was eliminated. The seismic response of the structure and soil became more severe as the acceleration amplitude of the input motion increased. It is indicated that possible shear damage of the soil and irreversible plastic deformation of the structure might have occurred as the test proceeded. The soft clay had a greater effect on the structure than that of the artificial rock. For the model structure, the tensile strain amplitude in the support region was larger than that in the midspan region. The support regions of the roof slab, lateral wall, and middle slab were the vulnerable components of the model structure during earthquakes.

scholarly journals Dynamic Response of Parallel Overlapped Tunnel under Seismic Loading by Shaking Table Tests

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tao Yang ◽  
Yunkang Rao ◽  
Honggang Wu ◽  
Junyun Zhang ◽  
Hao Lei ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Wavelet Packet ◽  
Failure Process ◽  
Side Wall ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Dynamic Strain ◽  
Shaking Table Tests ◽  
Failure Characteristics ◽  
The Right

Potential earthquake-induced damage to overlapped tunnels probably occurs during the operation and maintenance of mountain tunnel engineering, especially in the seismically active zone. This study investigated the dynamic response and the failure characteristics of the parallel overlapped tunnel under seismic loadings by employing shaking table tests. The failure mode of the parallel overlapped tunnels was analyzed through macroscopic test phenomena. The dynamic responses of the surrounding rock and tunnel lining were evaluated by acceleration and dynamic strain, respectively. In particular, wavelet packets were used to investigate the spectrum characteristics of the tunnel structure in depth. The failure process of the model can be divided into three stages. The upper-span and the under-crossing tunnels showed different failure characteristics. Additionally, the lining damage on the outer surface of the tunnel mainly occurred on the right side arch waist and the left side wall, whereas the lining damage on the inner surface of the tunnel mainly appeared on the crown and invert. Wavelet packet energy results showed that the energy characteristic distributions of the upper-span and the under-crossing tunnels were not consistent. Specifically, the energy eigenvalues of the crown of the upper-span tunnel and the invert of the under-crossing tunnel were the largest, which should be considered to be the weak parts in the seismic design.

scholarly journals Study on the Seismic Performance of Prefabricated Single-Segment Steel Jacket Bridge Piers

Symmetry ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2312
Author(s):  
Baodong Deng ◽  
Yanmin Jia ◽  
Dongwei Liang
Keyword(s):  
Seismic Performance ◽  
Shaking Table ◽  
Parameter Analysis ◽  
Dynamic Responses ◽  
Bridge Piers ◽  
Longitudinal Reinforcement ◽  
Anchorage Length ◽  
Single Segment ◽  
Steel Jacket ◽  
Bridge Models

To study the seismic performance of prefabricated single-segment steel jacket piers connected by grouting sleeves, two scaled symmetrical pier models with different anchorage lengths of the longitudinal reinforcement in the grouting sleeves and a comparative symmetrical cast-in-place (CIP) model were designed. OpenSees finite element models were established and shaking table tests were carried out on the three scaled pier models. The seismic response of each pier was compared and analyzed. Results showed the stiffness of the two prefabricated piers was greater than that of the CIP pier, and other seismic responses were less than those of the CIP piers, The dynamic responses of the two prefabricated bridge models were similar and changing the anchorage length of the reinforcement in the grouting sleeve had little effect on the seismic performance of the prefabricated pier. The simulation results were in good agreement with the experimental results. In the parameter analysis, the counterweight of the pier top had the greatest influence on the seismic performance of the prefabricated pier. The anchorage length of the longitudinal reinforcement in the grouting sleeve could be 6–14 times the diameter of the longitudinal reinforcement. Moreover, the seismic performance was found to be optimal when the thickness of the steel jacket was 5–7 mm.

scholarly journals Seismic Performance of Ni-Ti SMA Wires Equipped in the Spatial Skeletal Structure

2021 ◽  
Vol 8 ◽  
Author(s):  
Yang Liu ◽  
Tao Yang ◽  
Binbin Li ◽  
Bo Liu ◽  
Wentao Wang ◽  
...  
Keyword(s):  
Numerical Model ◽  
Vibration Control ◽  
Seismic Performance ◽  
Passive Control ◽  
Shaking Table Test ◽  
Experimental Tests ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Skeletal Structure ◽  
Performance Study

Nickel Titanium (Ni-Ti) Shape Memory Alloy (SMA) can be used to limit response of structure during external disturbances such as large seismic events. This paper presents a seismic performance study of Ni-Ti SMA wires equipped in the spatial skeletal structure. First, an improved Graesser-Cozzarelli (G-C) numerical constitutive model of the Austenitic phase of NiTi SMA wire is established. By contrast, the model based on uniaxial cyclic loading experimental tests is demonstrated as feasibility and validity. Next, a method consisting of a three-layer steel spatial skeletal structure model equipped with SMA wires is employed for simulation and experimental tests. According to the obtained constitutive numerical model, the simulation program of vibration control is written to simulate the effect of vibration control of seismic EL-centro wave. Furthermore, a shaking table experimental test was designed to verify the vibration control effect under the same action of seismic EL-centro wave. By comparison of the results of the numerical simulation and shaking table test, dynamic responses of the displacement and acceleration for different floors with control and without control was concluded. The superior superelastic properties of SMA wires used in passive control are investigated and the correctness of the constitutive numerical model are verified as well. The results show that such a comprehensive analysis integrates seismic-resistant behavior of Ni-Ti SMA wires in this type of structure. Besides, proposed method has broad application prospects to address the issues in passive control field of building structures.

scholarly journals Seismic Performance of Deposit Slopes with Underlying Bedrock before and after Reinforcement by Stabilizing Piles

2021 ◽  
Vol 11 (12) ◽  
pp. 5664
Author(s):  
Zhiliang Sun ◽  
Lingwei Kong ◽  
Wei Bai ◽  
Yong Wang
Keyword(s):  
Seismic Performance ◽  
Seismic Waves ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Ground Acceleration ◽  
Stabilizing Piles ◽  
Multi Stage ◽  
Before And After ◽  
Table Model ◽  
Input Motion

The seismic performance of stabilizing piles used to reinforce underlying bedrock in a deposit slope is a complex soil–structure interaction problem. Two centrifuge shaking table model testswere conducted to ascertain the dynamic responses of the underlying bedrock deposit slopes without and with the use of stabilizing piles during an earthquake. Multi-stage seismic waves with various peak accelerations were applied from the bottom of each model. The differencesin the response accelerations between the deposit and bedrock increase significantly with the increase in amplitude of the input seismic waves. The presence of the rock-socketed stabilizing piles can bridge the uncoordinated movement of the bedrock and the overlying deposit to some extent. The resultant force arising from a distributed load increment on the piles caused by an earthquake is mainly concentrated in the upper part. With increases in the peak ground acceleration of the input motion, the resistance of the bedrock in front of the stabilizing piles increases and the peak resistance under the bedrock surface of the stabilizing piles gradually moves downwards.This finding indicates that the strong seismic motion significantly changes the embedded working state of the stabilizing pile.

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