Influence of cement soil column on soil behavior.

Abstract

The present study is mainly based on the determination of the effect of cement soil on improving the bearing capacity of weak soil and decreasing the settlement. The program consists of installing a cement soil column with a fixed diameter (D = 0.1 m), various percentages of cement (0 ,3, 6, 9 and 12%) of soil weight and fixed length (L = 1.0 m). The column is supported by a circular steel plate with a diameter of 0.45 m and thickness 0.25 m to ensure the load is distributed uniformly from the hydraulic jack to the cement soil column in a very fine-sandy soil with traces of clay in El-Arish region placed in a soil chamber, and subjected to compressive axial load. The displacement underneath the plate was measured with a 2- dial gauge. Finite element package of a PLAXIS 3D version 2021 (A finite element code for soil analysis) has been done for the experimental program to compare the theoretical and experimental results. The obtained experimental test results indicated that increasing the percentage of cement has a significant effect on decreasing the settlement of soil and enhancing the bearing capacity of soil. As the untreated soil exhibited high compressibility, reaching a settlement of 1.65 cm under a stress of 4 kg/cm². This was reduced to 0.9 cm with 12% cement (demonstrating 45% reduction in settlement). Also, Study the effect of increasing number of cement column in the same area theoretically where (N = 1,2,3and4) cement column on settlement. On the other hand, studying the effect of spacing between cement soil column for 4 cement columns with various spacing S = (2.5D,3D,3.5D,4D) has been done theoretically. It was found that the settlement can be reduced by increasing the number of columns in a group but is adversely affected by increasing the spacing between them.