scholarly journals Introduction and Application of a Simple Probabilistic Liquefaction Hazard Analysis Program: HAZ45PL Module

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jui-Ching Chou ◽  
Pao-Shan Hsieh ◽  
Po-Shen Lin ◽  
Yin-Tung Yen ◽  
Yu-Hsi Lin
Keyword(s):  
Hazard Analysis ◽  
Probabilistic Approach ◽  
Soil Liquefaction ◽  
Shallow Foundation ◽  
Evaluation Procedure ◽  
Liquefaction Potential ◽  
Probability Map ◽  
Liquefaction Hazard ◽  
Potential Map ◽  
The Government

The 2016 Meinong Earthquake hit southern Taiwan and many shallow foundation structures were damaged due to soil liquefaction. In response, the government initiated an investigation project to construct liquefaction potential maps for metropolitans in Taiwan. These maps were used for the preliminary safety assessment of infrastructures or buildings. However, the constructed liquefaction potential map used the pseudo-probabilistic approach, which has inconsistent return period. To solve the inconsistency, the probabilistic liquefaction hazard analysis (PLHA) was introduced. However, due to its complicated calculation procedure, PLHA is not easy and convenient for engineers to use without a specialized program, such as in Taiwan. Therefore, PLHA is not a popular liquefaction evaluation procedure in practice. This study presents a simple PLHA program, HAZ45PL Module, customized for Taiwan. Sites in Tainan City and Yuanlin City are evaluated using the HAZ45PL Module to obtain the hazard curve and to construct the liquefaction probability map. The liquefaction probability map provides probabilities of different liquefaction potential levels for engineers or owners to assess the performance of an infrastructure or to design a mitigation plan.

scholarly journals Liquefaction hazard assessment and ground failure probability analysis in the Kathmandu Valley of Nepal

2022 ◽  
Vol 9 (1) ◽  
Author(s):  
Mandip Subedi ◽  
Indra Prasad Acharya
Keyword(s):  
Soil Liquefaction ◽  
Kathmandu Valley ◽  
Borehole Data ◽  
Gorkha Earthquake ◽  
Engineering Structures ◽  
Liquefaction Potential ◽  
Ground Failure ◽  
2015 Gorkha Earthquake ◽  
Scenario Earthquakes ◽  
Liquefaction Hazard

AbstractDuring the 2015 Gorkha Earthquake (Mw7.8), extensive soil liquefaction was observed across the Kathmandu Valley. As a densely populated urban settlement, the assessment of liquefaction potential of the valley is crucial especially for ensuring the safety of engineering structures. In this study, we use borehole data including SPT-N values of 410 locations in the valley to assess the susceptibility, hazard, and risk of liquefaction of the valley soil considering three likely-to-recur scenario earthquakes. Some of the existing and frequently used analysis and computation methods are employed for the assessments, and the obtained results are presented in the form of liquefaction hazard maps indicating factor of safety, liquefaction potential index, and probability of ground failure (PG). The assessment results reveal that most of the areas have medium to very high liquefaction susceptibility, and that the central and southern parts of the valley are more susceptible to liquefaction and are at greater risk of liquefaction damage than the northern parts. The assessment outcomes are validated with the field manifestations during the 2015 Gorkha Earthquake. The target SPT-N values (Nimproved) at potentially liquefiable areas are determined using back analysis to ascertain no liquefaction during the aforesaid three scenario earthquakes.

scholarly journals LPI Based Earthquake Induced Soil Liquefaction Susceptibility Assessment at Probashi Palli Abasan Project Area, Tongi, Gazipur, Bangladesh

2018 ◽  
Vol 10 (2) ◽  
pp. 105-116
Author(s):  
A. H. Farazi ◽  
N. Ferdous ◽  
A. S. M. M. Kamal
Keyword(s):  
Threshold Value ◽  
Flood Plain ◽  
Standard Penetration Test ◽  
Soil Liquefaction ◽  
Cumulative Frequency ◽  
Liquefaction Potential ◽  
Project Area ◽  
Potential Index ◽  
Liquefaction Hazard ◽  
Simplified Procedure

This study aims at evaluation of seismic soil liquefaction hazard potential at Probashi Palli Abasan Project area of Tongi, Gazipur, exploiting standard penetration test (SPT) data of 15 boreholes, following Simplified Procedure. Liquefaction potential index (LPI) of each borehole was determined and then cumulative frequency distribution of clustered LPI values of each surface geology unit was determined assuming cumulative frequency at LPI = 5 as the threshold value for liquefaction initiation. By means of geotechnical investigation two surface geological units—Holocene flood plain deposits, and Pleistocene terrace deposits were identified in the study area. We predicted that 14% and 24% area of zones topped by Pleistocene terrace deposits and zones topped by Holocene flood plain deposits, respectively, would exhibit surface manifestation of liquefaction as a result of 7 magnitude earthquake. The engendered hazard map also depicts site specific liquefaction intensity through LPI values of respective boreholes, and color index, which was delineated by mapping with ArcGIS software. Very low to low, and low to high liquefaction potential, respectively, was found in the areas covered by Pleistocene terrace deposits and Holocene flood plain deposits. LPI values of both units are such that sand boils could be generated where LPI > 5.

Liquefaction evaluation guidelines for practicing engineering and geological professionals and regulators

2001 ◽  
Vol 7 (4) ◽  
pp. 301-320 ◽  
Author(s):  
Marshall Lew
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Analytical Techniques ◽  
The United States ◽  
Lateral Spreading ◽  
The State ◽  
Hazard Mapping ◽  
Liquefaction Potential ◽  
Liquefaction Hazard ◽  
Flow Slides

Abstract Liquefaction is a seismic hazard that must be evaluated for a significant percentage of the developable areas of California. The combination of the presence of active seismic faults, young loose alluvium, and shallow ground water are the ingredients that could result in the occurrence of liquefaction in many areas of California. These ingredients are also found in other seismically active areas of the United States and the world. The state of California, through the Seismic Hazard Mapping Act of 1990, has mandated that liquefaction hazard be determined for new construction. On a parallel track, the Uniform Building Code, since 1994, has provisions requiring the determination of liquefaction potential and mitigation of related hazards, such as settlement, flow slides, lateral spreading, ground oscillation, sand boils, and loss of bearing capacity. Fortunately, the state of knowledge has now evolved to where there are field exploration methods and analytical techniques to estimate the liquefaction potential and the possible consequences arising from the occurrence of liquefaction. There are some areas that still need further research. Mitigation for liquefaction has become more commonplace and confidence in these techniques has been increased based on the relatively successful performance of improved sites in the past several major earthquakes. Unfortunately, not all practicing engineering and geological professionals and building officials are knowledgeable about the current state-of-practice in liquefaction hazard analysis and mitigation. Thus, it was considered necessary to develop a set of guidelines to aid professionals and building officials, based on California's experience with the current practice of liquefaction hazard analysis and mitigation. Although the guidelines reported in this paper were written specifically for practice in California, it is believed that guidelines can benefit practitioners to evaluate liquefaction hazard in all seismic regions.

scholarly journals Probabilistic Liquefaction Potential of Kathmandu Soil Based On Standard Penetration Tests

2021 ◽  
Author(s):  
Mandip Subedi ◽  
Indra Prasad Acharya
Keyword(s):  
Probabilistic Approach ◽  
Kathmandu Valley ◽  
Ground Acceleration ◽  
Liquefaction Potential ◽  
Earthquake Scenarios ◽  
Testing Procedures ◽  
Scenario Earthquakes ◽  
Liquefaction Hazard ◽  
First Order Second Moment ◽  
Penetration Tests

Abstract Despite being a liquefaction susceptible zone, Kathmandu Valley soil in Nepal has limited studies on liquefaction potential and most of them are based on the deterministic approach. Although this method is widely used, it ignores the uncertainties of seismic parameters such as peak ground acceleration, amax, and earthquake magnitude, Mw as well as the inherent variabilities of soil layers, in-situ testing procedures, and geotechnical properties. On the other hand, the probabilistic approach helps assess the liquefaction potential by considering all these uncertainties. In this study, we assess the liquefaction hazard in the Kathmandu Valley using the first-order second-moment (FOSM) method as a probabilistic approach for liquefaction hazard assessment. The assessment is done for three likely-to-recur scenario earthquakes utilizing the geotechnical data of 1510 boreholes. The soils are characterized geotechnically to further assess susceptibility criteria of liquefaction in the valley. The assessment reveals that the central part of the valley is more vulnerable to liquefaction than other parts and the liquefaction probability increases with increasing depth up to 9 m, after which has geared down the value. Moreover, a relationship between the probability of liquefaction (PL) and the factor of safety (FS) against liquefaction is established. The hazard maps prepared for different earthquake scenarios can be useful for future infrastructure planning in Kathmandu Valley.

scholarly journals Predicting the liquefaction potential of soil layers in Tabriz city via artificial neural network analysis

2021 ◽  
Vol 3 (7) ◽  
Author(s):  
Mohammad Alizadeh Mansouri ◽  
Rouzbeh Dabiri
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Soil Liquefaction ◽  
Data Sets ◽  
Liquefaction Potential ◽  
Advantages And Disadvantages ◽  
Artificial Neural ◽  
Artificial Neural Network Ann ◽  
Prediction Approach ◽  
Empirical Approaches

AbstractSoil liquefaction is a phenomenon through which saturated soil completely loses its strength and hardness and behaves the same as a liquid due to the severe stress it entails. This stress can be caused by earthquakes or sudden changes in soil stress conditions. Many empirical approaches have been proposed for predicting the potential of liquefaction, each of which includes advantages and disadvantages. In this paper, a novel prediction approach is proposed based on an artificial neural network (ANN) to adequately predict the potential of liquefaction in a specific range of soil properties. To this end, a whole set of 100 soil data is collected to calculate the potential of liquefaction via empirical approaches in Tabriz, Iran. Then, the results of the empirical approaches are utilized for data training in an ANN, which is considered as an option to predict liquefaction for the first time in Tabriz. The achieved configuration of the ANN is utilized to predict the liquefaction of 10 other data sets for validation purposes. According to the obtained results, a well-trained ANN is capable of predicting the liquefaction potential through error values of less than 5%, which represents the reliability of the proposed approach.

The use of MASW method in the assessment of soil liquefaction potential

2004 ◽  
Vol 24 (9-10) ◽  
pp. 689-698 ◽  
Author(s):  
Chih-Ping Lin ◽  
Cheng-Chou Chang ◽  
Tzong-Sheng Chang
Keyword(s):  
Soil Liquefaction ◽  
Liquefaction Potential ◽  
Masw Method
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