Assessment of Soil Liquefaction Potential Based on SPT Values at Some Ground Profiles in the North Central Coast of Vietnam

Nguyen Thanh Duong,Nguyen Thi Nu,Bui Truong Son

doi:10.24996/ijs.2021.62.7.12

Nguyen Thanh Duong, Nguyen Thi Nu + Show 1 more

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https://doi.org/10.24996/ijs.2021.62.7.12

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Abstract

The North Central Coast of Vietnam has a wide distribution of loose sand which is often exposed on the surface. The thickness changes from a few meters to over ten meters. This sand with the loose state can be sensitive to the dynamic loads, such as earthquakes, traffic load, or machine foundations. It can be liquefied under these loadings, which might destroy the ground and buildings. The Standard Penetration Test (SPT) is widely used in engineering practice and its values can be useful for the assessment of soil liquefaction potential. Thus, this article presents some ground profiles in some sites in the North Central Coast of Vietnam and determines the liquefaction potential of sand based on SPT and using three parameters, including the Factor of Safety against Liquefaction (FSLIQ), Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN). The research results show that the FSLIQ, LPI, and LSN values depend on the depth of sand samples and the SPT values. In this study, the sand distributed from 2.0 to 18.0m with (N1)60cs value of less than 20 has high liquefaction potential with FSLIQ<1, LPI is often higher than 0.73, and LSN is often higher than 10. The results also show that many soil profiles have high liquefaction potential. These results should be considered for construction activities in this area.

Highlights

Vietnam is the country having a long coastline and includes three main regions: the Northern, the Central, and the Southern regions
The main objective of this study is to evaluate the sand liquefaction potential by three parameters (FSLiq, Liquefaction Potential Index (LPI), and Liquefaction Severity Number (LSN)) in the North Central Coast of Vietnam based on Standard Penetration Test (SPT) values
The thickness of the sand layer in the North Central Coast of Vietnam varies from a few meters to more than ten meters and it is often exposed on the surface

Summary

Introduction

Vietnam is the country having a long coastline and includes three main regions: the Northern, the Central, and the Southern regions. In the Northern and Southern coastal areas, soft clay soil is mainly distributed in the deltas with the thickness varying from a few meters to more than 30-50 meters, which usually needs to be treated before construction 1-7. The thickness of loose sand changes from a few meters to over ten meters In this region, the demands for infrastructure development, such as building of roads and railway systems are on the rise. The loose sand layers are often distributed at the shallow depth and sensitive to the dynamic loads, such as earthquakes, traffic loads, and machine foundations. They can be liquefied under these loads and damage the buildings and constructions.

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