中砂地层渗透注浆模型试验研究

Model test of permeation grouting in medium sand stratum

以西安地铁8号线中砂地层为工程背景,采用自主研发的注浆模型试验装置试验研究了酸性浆液在不良级配中砂地层中的扩散规律。研究结果表明,磷酸-水玻璃浆液在砂土中主要以渗透注浆的形式进行扩散,注浆所形成的结石体多数呈现为“球形”,少数呈现为“柱形”。随着注浆压力的不断增加,注浆所形成的结石体也不断增大;当注浆压力由0.2 MPa增大至0.6 MPa时,结石体的高度由19.5 cm增大至28.5 cm,宽度由20.3 cm增大至29.6 cm。随着砂的含水率的不断增大,注浆所形成的结石体先增大后减小。当砂中水的质量分数达到10%时,结石体的高度为27.0 cm,宽度为27.4 cm,达到最大值。

Based on the medium sand layer of Xi’an Metro Line 8,the diffusion pattern of acidic slurry in the poorly graded medium sand layer was investigated using the self-developed grouting model test device.The results show that the phosphoric acid-sodium silicate slurry diffuses in the sand soil mainly through permeation,and most of the stones formed by grouting are“spherical”while a few are“columnar”.With the increase of grouting pressure,the volume of the grouted stone also increases.As the grouting pressure increases from 0.2 MPa to 0.6 MPa,the stone grows from 19.5 cm to 28.5 cm in height and from 20.3 cm to 29.6 cm in width.With the increase of water content in the sand,the volume of the grouted stone first increases and then decreases.When the water content of the sand reaches 10%,the grouted stone is 27.0 cm high and 27.4 cm wide,reaching its maximum value.