CONSTRUCTION OF FALLING HEAD PERMEAMETER AND DETERMINATION OF THE PERMEABILITY COEFFICIENT OF SANDY AND LATERITIC SOIL IN KHANA

ABSTRACT

The permeability coefficient of sandy and lateritic soil was carried out. In this work, falling head permeability test, sieve analysis, moisture content and Atterberg limit tests were performed on the soil samples collected from 5 different communities in Khana L.G.A of Rivers State. Experimental permeability coefficients of the soil was determined using falling head permeability test. The result of the falling head permeability test revealed that the permeability coefficient of laterite soil in Khana ranges from 0.005 – 0.073cm/s and that of sandy soil ranges from 0.113 – 0.929cm/s. The for laterite and sand is approximately 0.12mm.

CHAPTER ONE

INTRODUCTION

1.1 BACKGROUND OF STUDY

A certain number of problems relating to the interacting factor of soils had been the major concern of geotechnical engineers over the years. This is because the engineering properties of soils exhibits varying and uncertain behaviors, due to the complex and imprecise physical process associated with the formation of these materials which is a matter of concern for geotechnical engineers. Amongst the many interacting factors of the soil that the engineer has to deal with, permeability is one of its very important engineering properties (Whiteman, 1969) This reason is attributed to the fact that it plays a predominant role in solving of a good number of engineering problems such as settlement of buildings, yield of wells, seepage through and below the earth structures; it also controls the hydraulic stability of soil masses. It is important to note the permeability of soils is influenced by various factors such as particle size, structure of soils, shape of particles, void ratio, properties of water and degree of saturation (Handsbo, 1994). Furthermore, it is needful to mention that several methods can be adopted in the determination of the coefficient of permeability in the field and laboratory generally depending on the site conditions and type of soil. Other research works have been carried out to relate permeability and compaction characteristics of soils to their physical properties: Rowan and Graham (1948) used gradation, specific gravity, and shrinkage limit in their correlation equations, Davidson and Gardiner (1949) eliminated the specific gravity from the equations of Rowan and Graham (1948), but included a plasticity index.Taylor (1948) formulated a theoretical equation, based on the capillary tube model, for flow through porous media, relating the permeability with a representative grain size etc. The physical properties used generally include plasticity characteristics (liquid limit, plastic limit, shrinkage limit, and plasticity index), specific gravity, and grain size distribution that are attainable from relatively straightforward laboratory tests. However, specific index properties used in various correlation equations differ considerably. To ascertain the permeability coefficient of the soil, soil samples are to be collected and taken to the laboratory to carry out the above mention practical. For the purpose of this work, various soil samples have been collected from various locations within the study area to determine the permeability coefficient of the study area.

1.2 STATEMENT OF PROBLEM

Soil permeability is a key test for the determination of infiltration capacity of any soil. It aids the engineers to effectively control flooding in an area. Permeability coefficient also aids soil classification, dam design, filter construction, slope stability analysis and drainage design. This work is aimed at determining the permeability coefficient of sandy and lateritic soil in Khana Local Government area.

1.3 OBJECTIVES OF STUDY

The aim of this study is to determine the permeability coefficient of sandy and lateritic soil in Khana Local Government Area. The specific objectives of the study are: i. Determine the permeability coefficient of sandy and lateritic soil in Khana ii. To determine the coefficient of uniformity (Cu) for sandy and lateritic soil in Khana iii. To determine the Plastic and the Liquid limit values for Khana soil.