scholarly journals Seismic Analysis of Connections of Buried Continuous Pipelines

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Wei Liu ◽  
Chunjie Huang ◽  
Yunchang Wang ◽  
Peixin Shi

Buried pipelines serve as a critical component of lifeline systems, such as water and gas supply. They are interconnected to form a network to transport utilities. The connections change the geometry and stiffness of pipelines and impact the seismic response of the pipelines. This paper investigates the influence of connections on the seismic response of buried continuous steel trunk lines. A finite element model is introduced for analyzing the seismic response of buried pipeline networks. The seismic response of continuous steel pipelines with different connections, including cruciform and T-, K-, L-, and Y-shaped, is analyzed. The impact of site class, pipe diameter, branch angle, and angle of wave incidence on the response of pipe connections is explored. An influence coefficient defined to characterize the strain amplification at the connections is proposed for different forms of connections. Engineering measures to reduce the strain amplification at connections are suggested.

2020 ◽  
Vol 11 (2) ◽  
pp. 72-90
Author(s):  
Radhwane Boulkhiout ◽  
Salah Messast

The present study covers the influence of soil-structure interaction on the response of structures and civil engineering constructions under seismic excitation. The response of the structures being studied was evaluated, first, using a perfectly embedded structure at the base. Then, using two different models to model soil-structure contact, the finite element model and a rheological model (springs and dampers) in order to illustrate the impact of soil type behavior on structure response was considered based on periods, displacements, and stresses. On the other hand, the effect of superstructure type and its stiffness on the seismic response will be determined, first, using a reinforced concrete frame with shear walls and, second, using a girder bridge. Finally, in each model mentioned above, a parametric study was conducted to better understand the dynamic behavior of the analyzed structure. As for modelling by finite element method, the study was achieved using SAP2000 code.


2021 ◽  
Vol 1203 (3) ◽  
pp. 032043
Author(s):  
Iacopo Costoli ◽  
Stefano Sorace ◽  
Gloria Terenzi

Abstract Observation of damage caused by recent earthquakes highlights, once again, that the presence of infills significantly affects the seismic response of reinforced concrete (R.C.) frame buildings. Therefore, in spite of the fact that infills are non-structural elements, and thus they are normally not considered in structural analyses, in many cases their contribution should not be neglected. Based on these observations, the study proposed in this paper consists in the evaluation of the seismic response of infills in time-history finite element analyses of R.C. frame structures by means of a two-element model, constituted by two diagonal nonlinear beams. A “concrete”-type hysteretic model predicts the in-plane state of infills, through a force-displacement backbone curve expressly generated, and scanned in terms of performance limits, to this aim. This model is demonstratively applied to a real case study, i.e. a R.C. frame building including various types of brick masonry perimeter infills and internal partitions, damaged by the 30 October 2016 Central Italy earthquake. The time-histories seismic analyses carried out on it allows checking the influence of infills on the response of the structure, as well the effectiveness of the proposed model in reproducing the observed real damage on the masonry panels.


2010 ◽  
Vol 102-104 ◽  
pp. 150-154
Author(s):  
Xiao Ping Hu ◽  
Xiao Ping Ye

The seismic load usually has a significant hazard to the safety of the tower equipment, so it’s important to execute of seismic design in engineering practice. In this paper, the time history analysis of the seismic response is carried out with the help of ANSYS software for the finite element model of the adsorption tower. Relevant time history data is obtained. Compared with seismic analysis of the current standard method, corresponding suggestions are given.


2012 ◽  
Vol 256-259 ◽  
pp. 1496-1502 ◽  
Author(s):  
Da Lin Hu ◽  
Tian Qi Qu ◽  
Hong Bin Wang ◽  
Long Gang Chen

There are few researches on seismic response of reinforced concrete rib arch bridges at present; therefore, it is necessary to analyze seismic performance of this kind of bridges. Based on the engineering background of a three-span reinforced concrete rib arch bridge, a full bridge finite element model is built to analyze the structural dynamic characteristic and seismic response of the bridge. The internal forces and displacements of each key section is compared and discussed when the bridge is excited by horizontal unidirectional ground motion or the combination of vertical and horizontal ground motion. The structural seismic response calculated with different analysis methods is compared. The research results of this study can be used as a reference for the seismic design of similar bridges.


2020 ◽  
Vol 10 (14) ◽  
pp. 4850
Author(s):  
Thanh-Tuan Tran ◽  
Anh-Tuan Cao ◽  
Dookie Kim ◽  
Seongkyu Chang

The study investigates the collapse probability of a cabinet facility with a tuned mass damper (TMD) subjected to high- and low-frequency earthquakes. For this aim, a prototype of the cabinet in Korea is utilized for the numeric simulation. The accuracy of the finite element model is evaluated via the impact hammer tests. To mitigate the seismic response of the structure, a TMD system is developed whose properties are designed based on the outcomes from the modal analysis (i.e., modal frequencies and mode shapes). Furthermore, the influences of earthquake frequency contents on the seismic response are evaluated. The numeric analyses are conducted using a series of eighty earthquakes that are classified into two groups corresponding to low- and high-frequency motions. Finally, fragility curves are developed for the cabinet subjected to different ground motion sets. The results quantify the seismic vulnerability of the structure and demonstrate the influences of earthquake frequency contents and the vibration control system on the seismic response of the cabinet.


2014 ◽  
Vol 580-583 ◽  
pp. 1723-1728
Author(s):  
Tai Yu Song ◽  
Yin Shen ◽  
Guo Ping Li

A radius of curvature 20 times greater than the deck width of the bridge (R≥20b) is required as a specification in the regular bridge simplification conditions of the seismic response of curved girder bridges. Selecting benchmark bridges and employing parameter analysis method, this article studies on the effect of R/B value of the curved girder bridge on the response ratio of the seismic response calculated using the finite element model and that using a regular girder bridge. This study shows that on conditions that the deck width of the bridge is constant, the smaller the radius of curvature and the larger the B/R value (i.e., the smaller the R/B value) of the curved girder bridge are, the greater the difference between the seismic response of the curved girder bridge and the result calculated with a regular girder bridge is, and the difference is more significant under traverse seismic effect than that of longitudinal seismic effect. On conditions that the radius of curvature is constant, the impact of the change of B/R value due to the deck width change of the bridge on the difference between the seismic response of the curved girder bridge and the result calculated with a regular girder bridge is insignificant. Compared with the deck width of the bridge, the difference between the seismic response of the curved girder bridge and the result calculated with a regular girder bridge is more sensitive to the radius of curvature.


2012 ◽  
Vol 28 (3) ◽  
pp. 1117-1145 ◽  
Author(s):  
Goutam Mondal ◽  
Amit Prashant ◽  
Sudhir K. Jain

Interaction between a well foundation (caisson) and the surrounding soil during earthquake shaking involves complicated material and interface nonlinearities such as soil inelasticity, separation, sliding, and uplifting. It is often perceived that the interface nonlinearity has appreciable effects on the seismic response of the well foundation. This paper studies soil-well interface behavior during ground shaking and evaluates the significance of interface nonlinearity on the seismic response of the soil-well-pier (SWP) system. Seismic analysis of the soil-well-pier system was performed using the two-dimensional finite element model considering soil and interface nonlinearities, under both full- and partial-embedment conditions of the well foundation. Soil was assumed to be cohesionless and analyzed under both saturated undrained and dry conditions. Results of this model were compared with those of a model with perfectly-bonded interface. The design displacement and force resultants were found to be marginally overestimated and were on the conservative side in absence of nonlinear interface.


2020 ◽  
Vol 15 (1) ◽  
pp. 37-44
Author(s):  
El Mehdi Echebba ◽  
Hasnae Boubel ◽  
Oumnia Elmrabet ◽  
Mohamed Rougui

Abstract In this paper, an evaluation was tried for the impact of structural design on structural response. Several situations are foreseen as the possibilities of changing the distribution of the structural elements (sails, columns, etc.), the width of the structure and the number of floors indicates the adapted type of bracing for a given structure by referring only to its Geometric dimensions. This was done by studying the effect of the technical design of the building on the natural frequency of the structure with the study of the influence of the distribution of the structural elements on the seismic response of the building, taking into account of the requirements of the Moroccan earthquake regulations 2000/2011 and using the ANSYS APDL and Robot Structural Analysis software.


2019 ◽  
Vol 3 (Special Issue on First SACEE'19) ◽  
pp. 173-180
Author(s):  
Giorgia Di Gangi ◽  
Giorgio Monti ◽  
Giuseppe Quaranta ◽  
Marco Vailati ◽  
Cristoforo Demartino

The seismic performance of timber light-frame shear walls is investigated in this paper with a focus on energy dissipation and ductility ensured by sheathing-to-framing connections. An original parametric finite element model has been developed in order to perform sensitivity analyses. The model considers the design variables affecting the racking load-carrying capacity of the wall. These variables include aspect ratio (height-to-width ratio), fastener spacing, number of vertical studs and framing elements cross-section size. A failure criterion has been defined based on the observation of both the global behaviour of the wall and local behaviour of fasteners in order to identify the ultimate displacement of the wall. The equivalent viscous damping has been numerically assessed by estimating the damping factor which is in use in the capacity spectrum method. Finally, an in-depth analysis of the results obtained from the sensitivity analyses led to the development of a simplified analytical procedure which is able to predict the capacity curve of a timber light-frame shear wall.


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