Jet grouting piles were widely employed for ground reinforcement in building and infrastructure engineering due to the low cost and construction convenience. However, this foundation treatment method is not allowed to be used in high-speed railway involved constructions in China because of the concerning of the negative effect on the lateral displacement of the existing high-speed railway. To find a reasonable application distance of jet grouting piles away from existing high-speed railway bridge in deep soft soils with medium sensibility, a series of laboratory and in-situ tests on the influence of the jet grouting piling on the deformation of surrounding soils and adjacent high-speed railway bridge are carried out. The geological characteristics of the construction site and the mechanical properties of the soft soil are deeply investigated by utilizing field and laboratory tests. The piling induced lateral displacement of the surrounding soils is monitored as well as the displacement of an adjacent high-speed railway bridge. The monitoring data reveal that the influence area of the jet grouting piling is approximately 1.75 ∼ 1.85 times of the pile length in deep soft soils. The critical distance of the jet grouting piles from the existing high-speed bridge should be larger than 2 times of the pile length.

旋喷桩因其成本低、施工方便等特点，在建筑和基础设施工程中广泛应用于地基加固。但由于担心对既有高速铁路的横向位移产生负面影响，这种地基处理方法在我国不被允许在涉及高速铁路的建设中使用。为找到中等敏感性深层软土中旋喷桩距既有高铁桥梁的合理应用距离，通过一系列室内和现场试验，研究旋喷桩对周围土体变形的影响，毗邻的高铁大桥正在建设中。通过现场和室内试验，深入研究了施工现场的地质特征和软土的力学特性。监测桩引起的周围土壤的横向位移以及邻近高速铁路桥的位移。监测数据显示，深层软土中旋喷桩的影响面积约为桩长的1.75～1.85倍。旋喷桩距既有高速桥梁的临界距离应大于桩长的2倍。