钢筋混凝土灌注桩后压浆施工技术研究

Study on Post-grouting Technique for Cast-in-place Piles

钢筋混凝土灌注桩后压浆技术是利用预先设置在桩身内的压浆管,在钢筋混凝土灌注桩成桩过程中,将水泥浆液注入桩端与土层之间,加固桩端(侧)松软持力层,提高了竖向承载力。该项技术具有施工工艺简单、加固机理明确、加筋作用明显的特点。针对各类土质地层,对钢筋混凝土灌注桩进行压浆前后工程性状的比较,揭示了后压浆技术的内在规律,并针对施工中常见的一些问题提出了相应的应对措施。通过实际工程应用,用数据证明了灌注桩后压浆施工技术确实具有特定的加固作用,能够减小桩的长度、提高桩的极限承载力、减少桩的沉降量,从而改善了钢筋混凝土灌注桩的工程性状,降低工程造价。钢筋混凝土灌注桩后压浆技术是一项工艺简单、投资较少但能创造了较高经济效益的施工技术,值得推广。

The post-grouting technique for borehole grouting reinforced concert piles makes use of the pre-installation grouting pipes and injects the grout between the pile tip and the soil, which strengthens the soft bearing stratum and increases the vertical bearing capacity. The technique has the advantages such as the simple construction, the definite reinforcing mechanism and the obvious effect. Based on the comparison of the engineering behaviors of the piles in different strata before and after the grouting, some rules for the post-grouting technique are revealed, and the measures for the construction are presented. Through the engineering practice the data prove that the technique has the special reinforcing function and it could reduce the length of piles, increase the limit bearing capacity of piles and decrease the settlement of piles, which would improve the engineering behaviors of the piles and reduce the cost. The technique is of the simple process, low cost and high benefit which is worthy Of use widely.