Semi-Empirical Method for evaluating Risk of Liquefaction during earthquakes a Study Case of Rhiss Dam

Fatima Ezzahraa Latifi,Khadija Baba,Choukri Cherradi,Soukaina Touijrate,Lahcen Bahi,A Akhssas,E Cherkaoui,L Bahi,L Ouadif,F Benradi,A Lahmili,M Menzhi,M Khamar,A Nounah,K Baba

doi:10.1051/e3sconf/202015001004

Abstract

Liquefaction is a hazardous and temporary phenomenon by which water saturated soil loses some or all of its resistance. The undrained conditions linked to the cyclic load increase the pores water pressure inside the soil and consequently reduce effective stress. As a result, the soil can no longer resist or hold the shear forces, and lead to enormous deformations that directly influence the stability of structures and infrastructures foundations. Since 1964, several semi-empirical methods have been invented to evaluate the liquefaction potential using the in-situ test results. This study is based on the correlation between experimental data results of Menard pressuremeter and SPT dynamic penetrometer tests. Samples used in this test come from the Rhiss dam located in the North of Morocco, 24 kilometers as the crow flies from the town of Al Hoceima and south of the foundations of a calcareous ridge. The studied area have high seismic activity and a high percentage of fine soil elements, which suggests the possibility of soil liquefaction. We present and discuss the results of applying Idriss and Boulanger, and Youd et al methods in the evaluation of liquefaction susceptibility.

Highlights

One of the most important causes of major structural and engineering works disorders during earthquakes is the development of liquefaction in saturated sandy soils
The case studied is based on the SPT tests experimental results of the RHISS dam, located in the North of morocco
To study the ability of semiempirical methods to correctly verify the susceptibility of liquefaction by calculating the safety factor using the cyclic stress approach

Summary

Introduction

One of the most important causes of major structural and engineering works disorders during earthquakes is the development of liquefaction in saturated sandy soils. The main cause of soil liquefaction can be summarized as follows: if saturated sand undergoes ground vibrations, it tends to compact and decreases in volume. The effective pressure is cancelled, which makes the sand without resistance and develops a liquefaction state. The aim of this paper is, on the one hand, to signal the phenomenon of liquefaction which is responsible of high level of soil instability in Morocco, especially in the North. To study the ability of semiempirical methods to correctly verify the susceptibility of liquefaction by calculating the safety factor using the cyclic stress approach

Objectives

Results

Conclusion