scholarly journals Analysis of Dynamic p-y Curve Characteristics According to Mode Shape of Structure Using Shaking Table Tests

2021 ◽  
Vol 21 (5) ◽  
pp. 245-250
Author(s):  
Jae-hyeok Han ◽  
Seongnoh Ahn ◽  
Hyungchul Yoon ◽  
Jongwon Jung
Keyword(s):  
Seismic Design ◽  
Mode Shape ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Shaking Table ◽  
Soil Resistance ◽  
Shake Table Tests ◽  
Story Structure ◽  
Structure Interaction ◽  
Input Acceleration

In the seismic design of pile foundations, a p-y curve representing the nonlinear behavior of the ground considering the dynamic load of the earthquake is required. Recently, p-y curve analyses reflecting the soil-structure interaction have been conducted, but studies on multilayer structures have not been investigated extensively. In this study, the p-y curve characteristics were analyzed, considering the influence of the ground-structure interaction based on the mode shape of the structure (no structure, single-story structure, and three-story structure) through shake table tests. It was found that (1) the bending moment and pile displacement increased with input acceleration, and (2) the maximum soil resistance and pile displacement occurred at the natural frequencies of each structure were observed. In addition, the bending moment, soil resistance, and p-y curve slope were higher in the single-story structure than in the three-story structure. The findings indicate that the seismic design simulated for a single-story structure is conservative.

Performance of Multifiber Beam Element for Seismic Analysis of Reinforced Concrete Structures

2014 ◽  
Vol 14 (06) ◽  
pp. 1450013 ◽  
Author(s):  
Xuan Huy Nguyen
Keyword(s):  
Reinforced Concrete ◽  
Damage Mechanics ◽  
Seismic Analysis ◽  
Axial Strain ◽  
Nonlinear Behavior ◽  
Bending Moment ◽  
Axial Direction ◽  
Beam Element ◽  
Shaking Table ◽  
Rc Structures

This paper presents a simplified modeling strategy for simulating the nonlinear behavior of reinforced concrete (RC) structures under seismic loadings. A new type of Euler–Bernoulli multifiber beam element with axial force and bending moment interaction is introduced. To analyze the behavior of RC structures in the axial direction, the interpolation of the axial strain is enriched using the incompatible modes method. The model uses the constitutive laws based on plasticity for steel and damage mechanics for concrete. The proposed multifiber element is implemented in the finite element Code_Aster to simulate the nonlinear behavior of two different RC structures. One structure is a building tested on a shaking table; the other is a column subjected to cyclic loadings. The comparison between the simulation and experimental results shows that the performance of this approach is quite good. The proposed model can be used to investigate the behavior of a wider variety of configurations which are impossible to study experimentally.

Introducing Dynamic Nonlinear Soil-Foundation-Structure Interaction Effects in Displacement-Based Seismic Design

2013 ◽  
Vol 29 (2) ◽  
pp. 475-496 ◽  
Author(s):  
Roberto Paolucci ◽  
Raffaele Figini ◽  
Lorenza Petrini
Keyword(s):  
Seismic Design ◽  
Damping Ratio ◽  
Time History ◽  
Nonlinear Behavior ◽  
Interaction Effects ◽  
Structure Interaction ◽  
Soil Foundation ◽  
Displacement Based ◽  
Dynamic Time ◽  
Displacement Based Seismic Design

An iterative linear-equivalent procedure to take into account nonlinear soil-structure interaction effects in the displacement-based seismic design is presented for the case of shallow foundations. The procedure is based on the use of empirical curves to evaluate the stiffness degradation and the increase of damping ratio as a function of foundation rotation. Iterations are performed to ensure that admissible values of foundation rotations are complied with, in addition to the standard checks on structural displacements and drifts. Some examples of application of the approach to the design of bridge piers are provided. Design results are checked by means of nonlinear dynamic time-history analyses performed by a macro-element-based numerical tool, assuming nonlinear behavior of both structure and soil-foundation system.

Centrifuge Modeling on Seismic Behavior of Pile in Liquefiable Soil Ground

2013 ◽  
Vol 479-480 ◽  
pp. 1139-1143
Author(s):  
Wen Yi Hung ◽  
Chung Jung Lee ◽  
Wen Ya Chung ◽  
Chen Hui Tsai ◽  
Ting Chen ◽  
...  
Keyword(s):  
Seismic Behavior ◽  
Soil Structure ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Soil Liquefaction ◽  
Centrifuge Modeling ◽  
Shaking Table ◽  
Pile Head ◽  
Liquefiable Soil ◽  
Tip Mass

Dramatic failure of pile foundations caused by the soil liquefaction was founded leading to many studies for investigating the seismic behavior of pile. The failures were often accompanied with settlement, lateral displacement and tilting of superstructures. Therefore soil-structure interaction effects must be properly considered in the pile design. Two tests by using the centrifuge shaking table were conducted at an acceleration field of 80 g to investigate the seismic response of piles attached with different tip mass and embedded in liquefied or non-liquefied deposits during shaking. It was found that the maximum bending moment of pile occurs at the depth of 4 m and 5 m for dry sand and saturated sand models, respectively. The more tip mass leads to the more lateral displacement of pile head and the more residual bending moment.

Preliminary Parametric Assessment of a Bolted Endplate Joint under Combined Axial Force and Cyclic Bending Moment

2011 ◽  
Vol 255-260 ◽  
pp. 718-721
Author(s):  
Z.Y. Wang ◽  
Q.Y. Wang
Keyword(s):  
Finite Element Analysis ◽  
Axial Force ◽  
Seismic Design ◽  
Axial Load ◽  
Failure Modes ◽  
Bending Moment ◽  
Element Analysis ◽  
Cyclic Behaviour ◽  
Joint Behaviour ◽  
Steel Joints

Problems regarding the combined axial force and bending moment for the behaviour of semi-rigid steel joints under service loading have been recognized in recent studies. As an extended research on the cyclic behaviour of a bolted endplate joint, this study is performed relating to the contribution of column axial force on the cyclic behaviour of the joint. Using finite element analysis, the deteriorations of the joint performance have been evaluated. The preliminary parametric study of the joint is conducted with the consideration of flexibility of the column flange. The column axial force was observed to significantly influence the joint behaviour when the bending of the column flange dominates the failure modes. The reductions of moment resistance predicted by numerical analysis have been compared with codified suggestions. Comments have been made for further consideration of the influence of column axial load in seismic design of bolted endplate joints.

Seismic Response of Pile Groups Improved with Deep Cement mixing Columns in Liquefiable Sand: Shaking Table Tests

2021 ◽  
Author(s):  
Dingwen Zhang ◽  
Anhui Wang ◽  
Xuanming Ding
Keyword(s):  
Seismic Behavior ◽  
Lateral Displacement ◽  
Bending Moment ◽  
Pile Group ◽  
Shaking Table ◽  
Excess Pore Pressure ◽  
Shaking Table Tests ◽  
Pile Groups ◽  
Acceleration Response ◽  
Table Model

A series of shaking table model tests were performed to examine the effects of deep cement mixing (DCM) columns with different reinforcement depths on the seismic behavior of a pile group in liquefiable sand. Due to the DCM column reinforcement, the fundamental natural frequency of the model ground increases noticeably. The excess pore pressure of soils reduces with the increase of reinforcement depths of the DCM columns. Before liquefaction, the acceleration response of soils in the improved cases is obviously lower than that in the unimproved case, but the acceleration attenuation is greater after liquefaction in the unimproved case. Moreover, the lateral displacement of the superstructure, the settlement of the raft, and the bending moment of the piles in the improved cases are significantly reduced compared to those in the unimproved case, and the reduction ratios rise with the increase of reinforcement depth of the DCM columns. However, reinforcement by the DCM columns may result in the variation of the location of the maximum moment that occurs in the pile.

Computer Simulation of the Shaking Table Tests on Harder Soil-Structure Interaction System

2011 ◽  
Vol 261-263 ◽  
pp. 1619-1624
Author(s):  
Pei Zhen Li ◽  
Jing Meng ◽  
Peng Zhao ◽  
Xi Lin Lu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Soil Structure ◽  
Shaking Table Test ◽  
Shaking Table ◽  
Soil Structure Interaction ◽  
Shaking Table Tests ◽  
Site Condition ◽  
Element Analysis ◽  
Structure Interaction

Shaking table test on soil-structure interaction system in harder site condition is presented briefly in this paper. Three-dimensional finite element analysis on shaking table test is carried out using ANSYS program. The surface-to-surface contact element is taken into consideration for the nonlinearity of the state of the interface of the soil-pile and an equivalent linear model is used for soil behavior. By comparing the results of the finite element analysis with the data from shaking table tests, the computational model is validated. Based on the calculation results, the paper gives the seismic responses under the consideration of soil-structure interaction in harder site condition, including acceleration response, contact analysis on soil pile interface and so on.

PUSHOVER ANALYSIS BY ONE ELEMENT PER MEMBER FOR PERFORMANCE-BASED SEISMIC DESIGN

2010 ◽  
Vol 10 (01) ◽  
pp. 111-126 ◽  
Author(s):  
S. W. LIU ◽  
Y. P. LIU ◽  
S. L. CHAN
Keyword(s):  
Seismic Design ◽  
Design Method ◽  
Pushover Analysis ◽  
Nonlinear Behavior ◽  
Computational Effort ◽  
Effective Length ◽  
Single Element ◽  
Individual Element ◽  
Economical Design ◽  
Performance Based Seismic Design

Nonlinear static (pushover) analysis is an effective and simple tool for evaluating the seismic response of structures and offers an attractive choice for the performance-based design. As such, it has generally been used in modern design due to its practicality. However, the nonlinear plastic design method consumes extensive computational effort for practical structures under numerous load cases. Thus, an efficient element capturing the nonlinear behavior of a beam-column will be useful. In this paper, the authors propose a practical pushover analysis procedure using a single element per member for seismic design. As an improvement to previous research works, both P – Δ and P – δ effects as well as initial imperfections in global and member levels are considered. Therefore, the section capacity check without the assumption of effective length is adequate for present design and the conventional individual element design is avoided. The uncertainty of the buckling effects and effective length method can be eliminated and so a more economical design can be achieved. Two benchmark steel frames of three-storey and nine-storey in FEMA 440 were analyzed to illustrate the validity of the proposed method.

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