回填片石区既有建筑物地基微型桩注浆加固技术

Reinforcement technique of micro-pile grouting for existing building foundation in backfill schist area

在回填片石等大孔隙地层中,将钢花管微型桩和袖阀管劈裂注浆技术相结合,形成了钢花管微型桩控制性注浆施工技术,采用二次注浆工艺,第一次常压注浆采用浓浆对土层较大孔隙进行有效封堵,排除孔隙中的空气和水,显著提高土体密实度;二次劈裂注浆时,增大注浆压力,浆液在土体中自然向周边细小孔隙流动,加快固结效应。回填片石区钢花管微型桩控制性注浆施工工法操作方便、施工机具小、土层适应性强,既可以保证微型桩成桩质量,又可以精准控制浆液灌注量,对既有建筑的室内加固优势尤为明显。结合工程实例,论述了钢花管微型桩控制性注浆技术在既有建筑物回填片石层地基沉降加固治理中适用性和优越性,结果表明,该技术经济、环保、操作方便、加固效果好,符合工程实际需要。

In the backfilling of large porous strata such as rubble,the steel flower tube micro pile and sleeve valve tube splitting grouting technology are combined to form a steel flower tube micro pile control grouting construction technology.The second grouting process is adopted,and the first atmospheric pressure grouting uses concentrated slurry to effectively seal the larger pores of the soil layer,eliminate air and water in the pores,and significantly improve the compactness of the soil;During the secondary splitting grouting,increasing the grouting pressure will allow the slurry to naturally flow into the surrounding small pores in the soil,accelerating the consolidation effect.The controlled grouting construction method for steel flower pipe micro piles in the backfill stone area is easy to operate,with small construction equipment and strong soil adaptability.It can ensure the quality of micro piles and accurately control the amount of grout injected,which is particularly advantageous for indoor reinforcement of existing buildings.This article discusses the applicability and superiority of steel flower tube micro pile control grouting technology in the settlement reinforcement treatment of existing building backfill stone layer foundation through engineering examples.The results indicate that the technology is economically,environmentlly friendly,easy to operate,and has a good consolidation effect,which meets the actual needs of the project.