The Evaluation of Stone Column and Jet Grouting Soil Improvement by Conducting a Comprehensive Experimental Program

Abstract

Ground improvement is an important requirement in today`s construction industry as land reclamation is becoming increasingly popular. Many different ground improvement techniques have been developed over the past few decades to treat weak soil deposits. Two of commonly used techniques are jet grouting and vibro-stone column. The goal of this study is to investigate the advantages and disadvantages of both techniques using in-situ tests such as cone penetration testing, standard penetration testing, seismic wave velocity measurements and laboratory tests including direct shear tests, density and void ratio measurements on undisturbed samples obtained from the soil between produced columns. A test area including 25 jet grout columns with 1.8 m spacing and diameter of 60 cm was prepared to investigate the effectiveness of jet grouting method. A test area with same dimensions as it was for jet grout columns was prepared for stone columns. 25 stone columns with diameter of 1 m and spacing of 1.8 m were produced in the test area. Vibroflotation technique was used to produce stone column with top feeding method. In-situ and laboratory tests were carried out for these test areas to investigate the advantages and disadvantages of both techniques. The most important result obtained from in-situ tests was the better improvement of soil mass between stone columns than that of jet grout columns which plays a key role in reducing seismic risks and liquefaction hazards. Laboratory tests on undisturbed samples obtained from the soil between produced stone columns and jet grout columns also approved the findings from in-situ tests.