灌注桩后注浆技术在廊坊地区的应用研究

针对廊坊地区银丰大厦主楼和苏宁广场商业地块,采用灌注桩后注浆技术,进行了试验桩和工程桩的试验研究。结果表明:①利用试桩静载荷试验结果结合试桩施工、岩土特征分析,选择适宜的粉砂地层进行桩周注浆,是提高桩基础承载力和减小基础沉降变形的关键。工程桩经设计调整参数施工后,经静载荷试验,承载力及沉降变形均满足主体结构设计要求。②工程试桩施工采用双套筒施工工艺,可排除设计桩顶标高以上桩身的摩阻力影响,有利于静载荷试验在原地表进行,增强了检测工作的安全性,缩短了静载荷试验周期。

Applied Research on Post-grouting Technology of Bored Piles in Langfang Area

Aiming at main building of Yinfeng Building and commercial plot of Suning Square in Langfang Area, the bored pile post-grouting technology is adopted to perform experimental research on trial pile and engineering pile. The results show that: ①trial pile static loading test results combining trail pile construction and rock and soil features are analyzed. It’s especially important to select proper silt stratum to perform pile surrounding grouting, which is the key to improve the bearing capacity of pile foundation and reduce the settlement deformation of foundation. After parameter design and adjustment for engineering pile, through static loading test, the bearing capacity and settlement and deformation all meet the design requirements of main structure. ②The engineering trial pile construction with double sleeve can eliminate the influence of frictional resistance on pile body above the design pile top elevation, which is good for performing static loading test on the original ground, enhancing the detection safety and shortening the static loading test cycle.