Seismic behavior of underground structures and site response

Author(s):  
Y.M.A. Hashash
2006 ◽  
Vol 1 (3) ◽  
pp. 378-389 ◽  
Author(s):  
Kazuhiko Kawashima ◽  

A review on the seismic behavior and design of underground structures in soft ground is described focusing on the development of equivalent static seismic design called the seismic deformation method. Seismic isolation of underground structures is also presented.


Author(s):  
Naveen B. P. ◽  
Sitharam T. G. ◽  
Sivapullaiah P. V.

Seismic behavior of landfills need for a better understanding of the dynamic properties of municipal solid waste (MSW) and site response of MSW landfill during seismic events. This chapter presents unit weight, shear wave velocity, strain-dependent normalized shear modulus reduction, and material damping ratio relationships for Mavallipura landfill based on field testing, laboratory measurements, and validated using semi-empirical methods. In addition, one-dimensional seismic response analysis by an equivalent linear method for Mavallipura landfill, Bangalore is done using software like SHAKE2000 and DEEPSOIL. Results indicated that the MSW landfill has less shear stiffness and more amplification due to the loose filling and damping, which need to be accounted for by seismically safe MSW landfill design in India. Also, results of seismic response analyses performed by the authors and other researchers are examined to assess the impact of stiffness and height of the landfill refuse fill on the overall response.


Author(s):  
Amin Ghaznavi Oskouei ◽  
Asghar Vatani Oskouei

Underground structures perceived as one the most vital infrastructures,which include a variety of tunnels, subway lines,gas, oil and water pipe. Plenty of studies devoted to the investigationof the effect of wave propagation method on the seismicbehavior of steel pipelines. It should be mentioned thatanalyses have been carried out on both clayey and sandy soilwith different propagation speed in each of them. The aim ofthis research is the investigation of the effect of longitudinalp-wave propagation method on the amount of nonlinear strainsof pipeline with different way such as Pipe and Psi element or2D modelling of soil. It became evident that the amounts ofMaximum tension strain produced in the pipe have the maximumdifference, equaling 3.4 per cent. In addition, it investigatesthe effect of frequency of input motion on nonlinearstrains and the effect of frequency content in the results. 


The study of the transport and capture of particles moving in a fluid flow in a porous medium is an important problem of underground hydromechanics, which occurs when strengthening loose soil and creating watertight partitions for building tunnels and underground structures. A one-dimensional mathematical model of long-term deep filtration of a monodisperse suspension in a homogeneous porous medium with a dimensional particle retention mechanism is considered. It is assumed that the particles freely pass through large pores and get stuck at the inlet of small pores whose diameter is smaller than the particle size. The model takes into account the change in the permeability of the porous medium and the permissible flow through the pores with increasing concentration of retained particles. A new spatial variable obtained by a special coordinate transformation in model equations is small at any time at each point of the porous medium. A global asymptotic solution of the model equations is constructed by the method of series expansion in a small parameter. The asymptotics found is everywhere close to a numerical solution. Global asymptotic solution can be used to solve the inverse filtering problem and when planning laboratory experiments.


2015 ◽  
Vol 1 (1) ◽  
pp. 13-20
Author(s):  
Hamid Reza Samadi ◽  
Mohammad Reza Samadi

Due to the development of cities as well as rapid population growth, urban traffic is increasing nowadays. Hence, to improve traffic flow, underground structures such as metro, especially in metropolises, are inevitable. This paper is a research on the twin tunnels Of Isfahan's metro between Shariaty station and Azadi station from the North towards the South. In this study, simultaneous drilling of subway's twin tunnels is simulated by means of Finite Difference Method (FDM) and FLAC 3D software. Moreover, the lowest distance between two tunnels is determined in a way that the Law of Super Position could be utilized to manually calculate the amount of surface subsidence, resulted by drilling two tunnels, by employing the results of the analysis of single tunnels without using simultaneous examination and simulation. In this paper, this distance is called "effective distance". For this purpose, first, the optimum dimensions of the model is chosen and then, five models with optimum dimensions will be analyzed separately, each of which in three steps. The results of analyses shows that the proportions (L/D) greater than or equal 2.80, the Law of Super Position can be applied for prediction of surface subsidence, caused by twin tunnels' construction


2019 ◽  
Author(s):  
Hossein Alimohammadi ◽  
Mostafa Dalvi Esfahani ◽  
Mohammadali Lotfollahi Yaghin

In this study, the seismic behavior of the concrete shear wall considering the opening with different shapes and constant cross-section has been studied, and for this purpose, several shear walls are placed under the increasingly non-linear static analysis (Pushover). These case studies modeled in 3D Abaqus Software, and the results of the ductility coefficient, hardness, energy absorption, added resistance, the final shape, and the final resistance are compared to shear walls without opening.


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