压密注浆极限注浆压力研究

Research of limit grouting pressure in compaction grouting

为了避免压密注浆极限注浆压力在理论上一直没有理论解的弱点,依据压密注浆是以球形进行扩孔的假设,并利用球形扩孔过程中的能量和体变守恒原理以及砂土在压密注浆压力和地应力等较高应力同时作用下的应力-应变-体变关系,推导出压密注浆极限注浆压力求解的理论方程组,通过求解该方程组即可求解出压密注浆的极限注浆压力,可为计算高应力粒状土中压密注浆的极限注浆压力提供理论依据.分析表明,压密注浆的极限注浆压力值主要取决于土的应力-应变-体变关系,柱形扩孔时的压密注浆形式可以看成是球形扩孔时压密注浆的依次叠加.现场试验和计算分析可知,理论计算与工程实际较为吻合.

The limit pressure of spherical cavity expansion was solved by the law of conservation, in which the volume change of spherical cavity was balanced with the compression of granular soil and the energy given out from spherical cavity expansion was absorbed by the volume change and shear strain caused in granular soil. The stress-strain-volume change relationships and nonlinear strength behaviors of granular soils under high stresses were described. This method can be used to estimate the resistance of compaction grouting. The analysis shows that the limit pressure is determined by the characteristics of stress-strain-volume change relationships and the strength of granular soil,and has no concern with the pressure of super stratum. The theoretical values agree with the measured values from the field test.