干拌水泥碎石桩加固路基现场试验研究

针对京珠高速公路漯周界K421＋642-K421＋975段路基病害问题，采用干拌水泥碎石桩予以加固。为了研究其加固效果，现场试验段分为5个区，每区6根桩，桩长6m，成孔直径150mm，桩间距1m×1m，重锤120kg，每个区桩的每层虚填料高度、夯击次数不同。通过载荷试验、动力触探试验检测结果对比分析得出以下结论：每层虚填料高度小于40cm，夯击7次时，桩体达到密实状态，单桩承载力极限值达到400kPa，满足设计要求；通过静力触探、瑞利波测试及室内试验对比，分析加固前后路基土的变化，发现加固后路基含水量降低，路基的承载力和沉降得到改善。运行路基没有再出现唧泥、翻浆、路面病害等问题。上述分析和治理方法可为类似工程病害治理提供参考。

Gravel Pile of Dry Mixed Cement Trial Research in Reinforcing Subgrade

According to the Beijing-Zhuhai Expressway K421＋642-K421＋975 Subgrade disease problems, it is reinforced by dry mixing of cement rubble pile. In order to study the reinforcement effect, the test site is divided into 5 districts and each district has six piles, the length of pile is 6.0m, the diameter of pile is 150ram, the pile spacing is lmx lm and the weight of hammer is 120kg. The packing height of pile and the pound number of pile per layer is different on each district. By analyzing the results of the loading tests and the dynamic penetration test, when the packing height less than 40cm and the pound number more then 7, the pile body is closely dense state and bearing capacity characteristic value is 340kPa, and meet the design requirements; The variation is comparative analyzed by the results of the CPT, Rayleigh wave testing and laboratory tests of the reinforcement of subgrade before and after, the water content of reinforced subgrade is decreased, the subgrade bearing capacity and settlement is improved. Subgrade diseases have not been detected after they were treated one year. The analysis and control methods provide a reference for similar projects treatment.