Experimental study on shear strength of cracks in MICP solidified soil sites
Liu Xiaojun1,2 Gao Xin1,2 Pan Chaofan1,2
1. School of Civil Engineering, Xi’an University of Technology, Xi’an 710055, China;
2. Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering, Xi’an University of Technology, Xi’an 710055, China
Abstract：As cultural heritages, earthen sites have important historical, cultural and scientific values. However, as the main diseases, cracks seriously affect the stability and even cause damage of the earthen sites. Therefore, reasonable restoration and solidification of cracks in earthen sites should be carried out. As a green and environmentally friendly soil solidification technology, Microbial-induced calcium carbonate deposition (MICP) is not only environmentally friendly, but also has better compatibility with the raw materials of the site. In this paper, the site soil crack samples with different crack widths and structural plane roughness were prepared, and then grouted and solidified. Finally, the influence rules of crack width and structural plane roughness on the solidification effect were obtained through shear tests. The results show that the calcium carbonate cement deposits at the crack and cements the soil on both sides of the crack, which enhances the integrity and mechanical properties of the samples. The smaller the crack opening is, the rougher the structural plane is, and the greater the shear strength of the cured specimen is. The effect of the crack opening on the shear strength is greater than the roughness of the structural plane. When the crack opening is 0.5mm and the structural plane is rough, the cohesion of the cured specimen the internal friction angle can reach 38.18kPa and 33.42°, respectively.
