钢花管分段注浆工艺试验与检测

Tests and Detection of Multi-section Grouting Technique of Steel Grouting Pipes

注浆钢花管在基坑工程中的应用已经较为常见,可以作为防水措施或与其他结构形成复合支护体系以承担侧向荷载。全段二次间隔时间注浆是较为常用的工艺,该工艺在复杂地层条件下的适用性不强,常出现浆液在全段范围内无法均匀扩散的情况。鉴于该情况,开发了钢花管分段注浆结构,在碎石土地层进行了全段注浆和分段注浆的工艺对比试验。由于碎石地层孔隙通道发育,采用全段二次注浆工艺必须采取"多次少注",确保足够间隔时间的注浆方式才能确保注浆达到标准。而开发的分段注浆工艺能确保总注浆量,基本达到设计标准。工艺性试验前后的勘察检验验证了分段注浆工艺的注浆效果,注浆显著降低了渗透系数。试验后的水平承载力试验与反算验证了分段注浆工艺能够显著提高地基水平基床系数。

Steel grouting pipe was widely used in foundation excavation engineering. It can be used as anti-seepage structure assembled with other structures to afford lateral load as a composite supporting system. The full-section pipe grouting with time interval is a common technique. However,the grout can hardly diffuse uniformly along the whole pipe and is not applicable in complex stratums. A multi-section grouting structure system was developed and full-section grouting and multi-section grouting comparison tests were carried out in the gravelly soil stratums. The pore channels in the gravelly soil were strongly developed. If the full-section grouting is applied,we should inject grout more times and less grout each time so as to reach the design requirements. When the newly developed multi-section grouting was applied,the total amount of grout can be easily reached and the requirements can be reached. The investigation before and after the tests showed that the multi-section grouting can decrease the permeability of the soil significantly and good grouting effects can be obtained. The horizontal bearing capacity tests and the calculations also show that the multi-section grouting can increase the coefficient of subgrade reaction significantly.