Theoretical study on multiple holes grouting with natural boundary element method

Aiming at the cylinder grouting manner, according to the character of complex function, and based on the natural boundary element theory and Fourier series method, interaction problems of multiple holes grouting with arbitrary forms of hole-sitting are investigated for osmotic grouting. Considering the wall of the vertical shaft as impermeable stratum, the seepage pressure solution of exterior vertical shaft is deduced. The serum pressure distribution and relationships between serum pressure and consolidating distance are obtained. The results show that the grouting pressure of the shaft wall will increase while the radius of hole-sitting is small, and accordingly, the shaft wall will suffer from bad influence; the stratum can not be consolidated well if the radius of hole-sitting is large; when the consolidating width keeps the same, there is an optimal consolidating distance and the relative consolidating distance will be 2∼4.