Nonlinear Seismic Response Analysis of the Surrounding Rock-Tunnel System in the Mountain Areas Under SV Wave

The seismic responses and failure mechanisms of the tunnels embedded in the rock are quite different from those of the aboveground structures due to the dynamic interactions between tunnel and surrounding rock. In the previous studies, the tunnel models were under some extent of simplification without considering much of critical issues such as the three-dimensional (3D) characteristics, nonlinear mechanical properties or initial in-situ stress in the model, which are bound to bring the unpredictable errors in the evaluation of seismic response of tunnel-rock system. In this paper, some 3D nonlinear finite element models are established to evaluate the seismic response of surrounding rock-tunnel system in the mountain areas, considering the initial stress state of surrounding rock-tunnel system induced by gravity and excavation, General Mohr Coulomb nonlinear constitutive. Based on the proposed model, the optimal value of the longitudinal length of the model is firstly discussed to determine the value range of the model size. After that, a series of numerical parametric analyses are carried out to investigate the deformation of the surrounding rock. One important finding is that there exists a most unfavorable stress condition which makes the tunnel induce maximum seismic responses. Finally, the typical control variable method is employed to compare the results of the models established in this paper with those of the model considering or not some of significance factors, the comparison results further prove the necessity of establishing the 3D nonlinear model.

Download Full-text

Elasto-Plastic Analysis of Seismic Response of Valve-Hall Structure with Suspension Valves of Large-Scale Converter Station

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.94-96.1941 ◽

2011 ◽

Vol 94-96 ◽

pp. 1941-1945

Author(s):

Yi Wu ◽

Chun Yang ◽

Jian Cai ◽

Jian Ming Pan

Keyword(s):

Seismic Response ◽

Large Scale ◽

Seismic Waves ◽

Tensile Force ◽

Response Analysis ◽

Vertical Acceleration ◽

Seismic Responses ◽

Seismic Response Analysis ◽

Finite Element Software ◽

Plastic Analysis

Elasto-plastic analysis of seismic responses of valve hall structures were carried out by using finite element software, and the effect of seismic waves on the seismic responses of the valve hall structures and suspension equipments were studied. Results show that significant torsional responses of the structure can be found under longitudinal and 3D earthquake actions. Under 3D earthquake actions, the seismic responses of the suspension valves are much more significant than those under 1D earthquake actions, the maximum tensile force of the suspenders is about twice of that under 1D action. The seismic responses of the suspension valves under vertical earthquake actions are much stronger than those under horizontal earthquake actions, when suffering strong earthquake actions; the maximum vertical acceleration of the suspension valves is about 4 times of that under horizontal earthquake actions. It is recommended that the effects of 3D earthquake actions on the structure should be considered in seismic response analysis of the valve hall structure.

Download Full-text

Seismic Response Analysis of Concrete Lining Structure in Large Underground Powerhouse

Mathematical Problems in Engineering ◽

10.1155/2017/4106970 ◽

2017 ◽

Vol 2017 ◽

pp. 1-14 ◽

Cited By ~ 2

Author(s):

Xiaowei Wang ◽

Juntao Chen ◽

Ming Xiao ◽

Danqi Wu

Keyword(s):

Constitutive Model ◽

Seismic Response ◽

Surrounding Rock ◽

Concrete Lining ◽

Response Analysis ◽

Analysis Method ◽

Stability Calculation ◽

Concrete Material ◽

Underground Powerhouse ◽

Lining Structure

Based on the dynamic damage constitutive model of concrete material and seismic rock-lining structure interaction analysis method, the seismic response of lining structure in large underground powerhouse is studied in this paper. In order to describe strain rate dependence and fatigue damage of concrete material under cyclic loading, a dynamic constitutive model for concrete lining considering tension and shear anisotropic damage is presented, and the evolution equations of damage variables are derived. The proposed model is of simple form and can be programmed into finite element procedure easily. In order to describe seismic interaction characteristics of the surrounding rock and lining, an explicit dynamic contact analysis method considering bond and damage characteristics of contact face between the surrounding rock and lining is proposed, and this method can integrate directly without iteration. The proposed method is applied to seismic stability calculation of Yingxiuwan Underground Powerhouse, results reveal that the amplitude and duration of input seismic wave determine the damage degree of lining structure, the damage zone of lining structure is mainly distributed in its arch, and the contact face damage has great influence on the stability of the lining structure.

Download Full-text

Structure Strengthening Method for Enhancing Seismic Behavior of Soft Tunnel Portal Section

Mathematical Problems in Engineering ◽

10.1155/2021/6624963 ◽

2021 ◽

Vol 2021 ◽

pp. 1-12

Author(s):

Guangyao Cui ◽

Jianfei Ma

Keyword(s):

Seismic Response ◽

Seismic Performance ◽

Shaking Table Test ◽

Soft Rock ◽

Surrounding Rock ◽

Shaking Table ◽

Key Factor ◽

Rock Tunnel ◽

Tunnel Portal ◽

Strengthening Method

Tunnel portal sections always suffer serious damage under strong earthquakes. This paper aims to study the seismic performance of lining strengthening method in soft rock portal section by employing the model test. Firstly, the shaking table test considering the test cases, the modified input motions, the boundary condition, and monitoring equipment are conducted to simulate the seismic response of the soft tunnel portal section. Then, the lining strengthening method of increasing concrete grade is applied to the tunnel structure to study the aseismic performance of the soft rock tunnel portal section, and the seismic effects of the tunnel linings with different concrete grades are compared and analyzed. The result shows that the proportion of soft rock to total surrounding rock is the key factor affecting the seismic response of soft rock tunnel portal section; the larger the proportion of soft rock in surrounding rock, the more vulnerable the structure to earthquake damage; the seismic performance of the lining strengthening in hard rock portal is remarkable while limited in soft rock portal section. The stiffness and strength of the lining are larger than those of surrounding rock; the seismic performance of the soft portal section could hardly be improved only by the lining strengthening method. It is suggested to adopt both the structure strengthening and isolation method in the seismic design of soft portal section.

Download Full-text

Seismic Response Analysis of the Numerical Simulation Method on Cable-Stayed Bridge Tower which Considers the Rigid Foundation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.875-877.998 ◽

2014 ◽

Vol 875-877 ◽

pp. 998-1002

Author(s):

Wei Bing Luo ◽

Ji Ming Fan ◽

Ji Lv ◽

Li Ya Zhang ◽

Cui Cui Wu

Keyword(s):

Seismic Response ◽

Ground Motions ◽

Simulation Method ◽

Response Analysis ◽

Rigid Foundation ◽

Seismic Responses ◽

Near Fault ◽

Cable Stayed Bridge ◽

Long Span ◽

Bridge Tower

The seismic responses under the action of far-fault and near-fault ground motions of the bridge tower structure of the long-span cable-stayed bridge are numerically discussed by means of the model of the bottom consolidation of the column. The results show that the responses of tower of the cable-stayed bridge correlate well with the properties of the ground motions. The seismic responses of the model have much larger values under the near-fault velocity pulse-like ground motions than those of the counterpart. The frequency of system reduces as the flexibility of structure decreases because of the rigid foundation; The displace response of tower shows that the rigid foundation has little influence on the seismic response of the cable-stayed bridge, while the acceleration response of the tower implies that rigid foundation has adverse effect. Thus, consideration of the soil-pile-superstructure interaction can be meaningful both in theory and reality during the seismic design of long-span cable-stayed bridge structure.

Download Full-text

Elastic Seismic Response of Steel-Concrete Composite Frames with Partial Interaction

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.268-270.729 ◽

2012 ◽

Vol 268-270 ◽

pp. 729-732

Author(s):

Jin Xi Duan ◽

Z. Shen

Keyword(s):

Boundary Condition ◽

Seismic Response ◽

Slip Boundary Condition ◽

Frame Structures ◽

Response Analysis ◽

Seismic Responses ◽

Shear Connection ◽

Slip Boundary ◽

Composite Frames ◽

Partial Interaction

The finite element formulations of steel-concrete composite (SCC) beams considering interlayer slip with end shear restraint is established. Elastic seismic response of SCC frame structures under different shear connection stiffness and slip boundary conditions are examined. The influences of the shear connection stiffness and the slip boundary condition on elastic seismic response are analyzed. With the shear connection stiffness increasing, the free vibration frequencies increase and the seismic responses decrease. The natural vibration properties of SCC frame structures and seismic responses are also significantly affected by the slip boundary condition, and it should be properly imposed on all composite beams in seismic response analysis.

Download Full-text

Seismic Response Analysis for Tunnel Conveying Water under Traveling Waves Excitation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.2050 ◽

2012 ◽

Vol 166-169 ◽

pp. 2050-2053

Author(s):

Jin Yun Liu ◽

Cai Chu Xia ◽

Sheng Nan Sun

Keyword(s):

Seismic Response ◽

Traveling Wave ◽

Large Scale ◽

Water System ◽

Response Analysis ◽

Wave Effect ◽

Earthquake Excitation ◽

Traveling Wave Effect ◽

Variation Characteristics ◽

Rock Tunnel

For large-scale water-conveying tunnel, the spatial variation characteristics of earthquake excitation, namely, multi-point input has great effects on seismic response of the water-conveying tunnel. Aim at this problem, the paper considers interaction of surrounding rock-tunnel lining-water system and considers traveling wave effect. The result indicates: compare with the coincident earthquake excitation, traveling wave effect brings disadvantageous influence on seismic response of the water-conveying tunnel.

Download Full-text

Study on Effects of Sea Ice on Nonlinear Seismic Responses of Single-Column Pier Subject to Different Types of Earthquakes

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.166-169.2298 ◽

2012 ◽

Vol 166-169 ◽

pp. 2298-2303

Author(s):

Fu Qiang Qi ◽

Bo Song

Keyword(s):

Sea Ice ◽

Seismic Response ◽

Response Analysis ◽

Seismic Responses ◽

Analysis Model ◽

Maximum Displacement ◽

Ductility Demand ◽

Nonlinear Seismic Response ◽

Single Column ◽

Different Types

The seismic response analysis model of a single-column pier surrounded by sea ice was established and it analyzed the nonlinear seismic response of the pier subject to different types of earthquakes. The results show that the maximum seismic responses of the pier occur when the mass of sea ice is about 5000~10000 ton, which should be used to design a pier. When the sea ice is considered, the curvature ductility demand coefficient，the maximum displacement and the maximum residual displacement of the pier are several times than those corresponding to without sea ice, and the M-Ø hysteretic curves of the cross-section of the pier subject to earthquakes present downfallen ‘S’ form significantly and the deformability and energy dissipation capability of the pier drop remarkably.

Download Full-text

Seismic Response Analysis of Piping Systems With Nonlinear Supports Using Differential Algebraic Equations

Journal of Pressure Vessel Technology ◽

10.1115/1.1634589 ◽

2004 ◽

Vol 126 (1) ◽

pp. 91-97 ◽

Cited By ~ 6

Author(s):

Katsuhisa Fujita ◽

Tetsuya Kimura ◽

Yoshikazu Ohe

Keyword(s):

Seismic Response ◽

Time History ◽

Differential Algebraic Equations ◽

Response Analysis ◽

Algebraic Equations ◽

Seismic Responses ◽

Seismic Response Analysis ◽

Nonlinear Seismic Response ◽

Piping Systems ◽

Time History Response

Hysteresis elements such as elasto-plastic dampers are important elements for mechanical structures, especially for earthquake-proof structures. When such nonlinear supports are utilized for piping systems, the nonlinearities of the hysteresis elements and the geometrical complexity of the piping systems lead to complicated seismic responses, and thus further studies are required in order to enhance the reliability of the earthquake-proof design. In the seismic response analysis, the method of time history response analysis is widely used. In this paper, a method of nonlinear seismic response analysis for a piping systems using a combination of the FEM and the Differential Algebraic Equations (DAE) is proposed. As it is well known, the DAE is suitable for numerical analysis of time history responses for mechanical structures and machinery elements. According to the advantage of the DAE, the numerical modeling and simulation of a complex piping systems supported by the hysteresis elements can be easily carried out by using the proposed method. In order to verify the usefulness of the method, the time history responses of piping systems supported by a elasto-plastic damper is examined for seismic excitation by using the proposed method. The damper is modeled as a bilinear model. The effects of the second stiffness and the stiffness associated with the plastic deformation of the damper on the seismic responses are investigated using an actually recorded earthquake motion.

Download Full-text