The settlement evaluation of improved soft clay using leca replacement technique

Abstract

Soil replacement technique is the easiest and oldest method to improve the soft soils underneath the shallow foundations by reducing the settlement by replacing weak soil (e.g. medium or soft clay and organic soils) with more competent materials such as sand, gravel or other suitable granular materials. This paper presents the research on soft soil improvement underlain a large embankment using Lightweight Expanded Clay Aggregate (LECA) as a replacement material which is substitute of normal aggregate. LECA has been used successfully in geotechnical application where weight is an issue because the materials can help reduce dead loads by more than half. The analysis of performance of LECA as a replacement material was conducted through finite elements methods by using Plaxis 3D software and the recorded settlement magnitude then were compared to Tarzaghi’s equations for evaluating the average settlement of uniform loading. The obtained results demonstrated that the settlement decreases with increasing of LECA replacement thickness. Keywords: Soft clay, settlement, numerical modelling, soil improvement, replacement technique