Pore pressure response analysis for earthquakes

1985 ◽  
Vol 22 (4) ◽  
pp. 466-476 ◽  
Author(s):  
Ashok K. Chugh ◽  
J. Lawrence Von Thun
Keyword(s):  
Pore Pressure ◽  
Effective Stress ◽  
Computer Programs ◽  
Pressure Response ◽  
Response Analysis ◽  
Earthquake Loading ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Soil Deposits ◽  
Pore Pressure Response

Modifications and extensions made to the computer programs APOLLO and GADFLEA for studying the generation and dissipation of pore water pressure in soil deposits under earthquake loading are presented. The revised versions of these computer programs permit a fuller use of the analytically estimated site-specific earthquake response of soil deposits. These changes do not, however, alter the basic formulation of the problem and the solution strategies implemented in the computer programs APOLLO and GADFLEA. It is argued that the dynamic pore pressure response results obtained through these programs when used iteratively with the total stress ground response analysis should yield results close to the true effective stress ground response analysis for earthquake loading. Key words: pore pressure, earthquakes, soil dynamics, analysis, effective stress, computer programs, liquefaction.

Investigation of the Performance of Simplified Constitutive Models in Nonlinear 1D Effective Stress Ground Response Analysis

2021 ◽  
Author(s):  
Caroline Bessette ◽  
Samuel Yniesta
Keyword(s):  
Pore Pressure ◽  
Ground Motion ◽  
Effective Stress ◽  
Spectral Response ◽  
Constitutive Models ◽  
Excess Pore Pressure ◽  
Response Analysis ◽  
Total Stress ◽  
Ground Response ◽  
Ground Response Analysis

ABSTRACT Several building codes, such as the National Building Code of Canada, recommend that an effective stress ground response analysis be performed if a liquefiable stratum is identified within a soil profile. Although, constitutive models for total stress ground response analysis have been well verified against earthquake recordings, existing models for effective stress ground response analysis have yet to be thoroughly validated. This article investigates the predictions of five pore pressure models derived for effective stress ground response analysis. First, a dataset of five downhole arrays and two centrifuge experiments in which a potential of liquefaction was identified is presented. The profiles and ground-motion recordings are selected to represent a broad range of soil properties, ground-motion intensities, and excess-pore pressure generation levels. The differences between predictions of the effective stress models against commonly used 1D ground response total stress equivalent-linear and nonlinear analyses are evaluated. The predicted and measured motions are compared in terms of spectral response and amplification factor. The pore pressure response of all models is evaluated as a function of shear strain and found to agree well with published correlations representing the expected behavior of liquefiable soils. Although, the models show the ability to capture liquefaction triggering, the results indicate that for the selected dataset, total stress simulations were found to be, at least, as precise and accurate as the effective stress simulations. Therefore, simplified models for effective stress ground analysis should be used with caution by practicing engineers to predict surface spectra but can be used confidently to assess the potential for liquefaction triggering.

ENGINEERING CHARACTERISTICS AND EARTHQUAKE RESPONSE ANALYSIS OF GROUND

2018 ◽  
Vol 5 (2) ◽  
Author(s):  
Haruyuki Yamamoto ◽  
Munkhunur Togtokhbuyan
Keyword(s):  
Shear Modulus ◽  
Ground Surface ◽  
Response Analysis ◽  
Soil Profiles ◽  
Lumped Mass ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Natural Period ◽  
Soil Deposits ◽  
Computational Procedures

One-dimensional layered soil lumped mass ground response analysis was conducted for the representative site in Ulaanbaatar, Mongolia. The surficial geology of the site is predominantly composed of the gravely and sandy soil typical of this region in the central part of Ulaanbaatar. The natural period of soil profiles needs to be investigated under several circumstances. For example, these parameters-based study has indicated that damage due to earthquakes occurs when the natural periods, T1 and T2, of the ground are closer to that of a superstructure. Various computational procedures or methods have been proposed for this kind of the ground response analysis. In this paper, the numerical analysis method such as the lumped mass method within eigenvalue analysis is used to determine the natural periods of the ground. The ground surface, soil deposits, and bedrock are assumed to be horizontal. The soil deposits are subjected to shear deformation such as shear modulus, G, on the other hand, excitation of vibration could be a shear modulus on each layer. As well as to determine an engineering bedrock depth in the site, the methodology that is utilized in this paper is focused on the use of the correlation between SPT-N value and soil elastic Young's modulus, E, in the soil profiles, and used over 100 boreholes data with SPT-N values in the vicinity of Ulaanbaatar.

scholarly journals The Use of Ground Motion Parameters to identify the Liquefaction during a Strong Earthquake in Northern Thailand

2021 ◽  
Vol 27 (1) ◽  
pp. 1-8
Author(s):  
Lindung Zalbuin Mase
Keyword(s):  
Pore Pressure ◽  
Amplification Factor ◽  
Pressure Ratio ◽  
Excess Pore Pressure ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Northern Thailand ◽  
Motion Parameters ◽  
Excess Pore

This paper presents a ground response analysis to simulate the liquefaction phenomenon during the 2011 Tarlay Earthquake in northern Thailand. The site investigation data and geophysical measurements on 7 sites in northern Thailand were collected. The multi-springs element model was implemented in finite element ground response analysis. Several parameters, such as peak ground acceleration, peak ground velocity, amplification factor, excess pore pressure ratio, were observed. Furthermore, the correlation from the ground motion parameters was generated to estimate liquefaction potential, which was represented by excess pore pressure ratio. The result showed that the excess pore pressure ratio was relatively well correlated with several ground parameters, such as amplification factor, velocity-acceleration ratio, and factor of safety against liquefaction. The results could be also used for the engineering practice in predicting liquefaction potential in Northern Thailand.

scholarly journals Reliability on ProSHAKE 2.0 in the Assessment of One Dimensional Ground Response Analysis through Verification Example

2019 ◽  
Vol 8 (4S2) ◽  
pp. 56-59
Keyword(s):  
Maximum Amplitude ◽  
Response Spectra ◽  
Response Analysis ◽  
Ground Response ◽  
Ground Response Analysis ◽  
Peak Displacement ◽  
Earthquake Motion ◽  
Soil Deposits ◽  
Time Histories ◽  
Frequency Domain Approach

It is understood from the recent destructive earthquakes, topography, nature of the bedrock and geometry of the soil deposits are the prime factors that made modifications to the underlying earthquake motion. The influence of such confined soil states on the strong earthquake motion plays a significant task in accessing the uniqueness of ground action. In this paper, the response of the soil layers to the earthquake action of the bedrock directly under it is determined. The analysis is done through frequency domain approach. Pro-shake software 2.0 is used to arrive the reliability of the ground response study. A wide variety of output parameters such as time histories of acceleration, velocity, displacement, shear stress, shear strain, response spectra and maximum amplitude of various parameters with depth are plotted and the other scalar parameters such as peak acceleration, peak velocity, peak displacement, RMS acceleration, arias intensity, predominant period and bracketed duration was computed.

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