Strength Properties and Settlement-time curve of Floating Soil-Cement Column Provided by Simple Method

Abstract

This research aims to study the strength property in term of unconfined compressive strength (q_u) and investigate the settlement-time curve of floating soil-cement column set up by the simple method for using in local community. This simple method is able to conduct with ease and the instruments of soil-cement column making are able to be provided and operated easily by the local people. For the process of proposed method, there are 4 steps as followings 1) Making a hole 2) Mixing soil with water 3) Soil-cement mixing and 4) Soil-cement installation. The effectiveness of the simple method was demonstrated by comparing with the jet grouting method in term of the q_u value and dry density (r_d) of soil cement column. The testing site was located in Pathumthani, Thailand which the soil layer is a soft clayey deposit. The soil cement columns with the diameter of 0.50 m and length of 4.0 m were constructed by the proposed method and by the jet grouting method. The specimens of testing were collected by using the coring machine. The comparisons of testing results are shown that the q_u value of soil cement column by the proposed method is less slightly than that by the jet grouting method. The increasing of curing period increases the q_u value and the modulus of elasticity (E₅₀) for both methods. The tendency of q_u-g_d relationship by the proposed method is the same as that by the jet grouting method. This means the greater g_d value, the greater q_u value. For the settlement-time curve, the results of both method have the same tendency. The settlement by simple method is higher slightly than that by jet grouting method. Thus, the proposed method can be used to construct the soil-cement column for improving the soft clayey deposit by local people due to easy procedures. The construction tools can also be provided with availability in the local country.