袖阀管劈裂注浆加固粉土路基实验研究

Model tests on fracture grouting reinforcement of silt embankment by using Soletanche method

通过室内大型模拟实验,对粉土路基强度、刚度在毛细水作用下的衰减规律和袖阀管劈裂注浆加固路基的效果进行研究。实验模拟新建路基、潜水位20 cm/50 cm的毛细水作用路基、袖阀管注浆劈裂土体加固路基等4个工况,得到粉土路基土体含水率的分布规律和物理力学指标;在分级循环加卸荷载的作用下,得到路基模型总体刚度、受力和变形的特性;挖除路基模型,观察袖阀微桩及浆液扩散的形态。结果表明:毛细水作用可使粉土路基模型总体刚度降低70%,土体抗剪强度下降,路基竖向塑性变形随荷载增大快速增加;水平分层劈裂土体凝固的浆液不仅阻断了毛细水的上升通道,而且与底端扩大的微桩形成空间骨架与土体共同作用,骨架与土体各承担荷载大约50%,袖阀管加固粉土路基效果显著。

Based on large-scale indoor model tests, the attenuation law of strength and stiffness of silt embankment under the action of capillary water and the reinforcement effect of the embankment by using the Soletanche method are studied. Four working conditions, newly constructed embankment, attenuated embankments affected by the capillary water with different groundwater levels （20 and 40 cm） and fracture grouting reinforced embankment, are simulated, Moisture content distribution, physical and mechanical properties of the silt embankment are detected. General stiffness, force and deformation characteristics of the embankment model are obtained under grading cyclic loading and unloading conditions. Micro-piles and fracture grouting spread forms are observed during the excavation of the embankment model. The test results indicate that the general stiffness of the silt embankment will reduce by 70% because of the capillary water, the shear strength of embankment soil will decline, and the vertical plastic deformation of the embankment increases rapidly with the increasing load. The horizontal layered fracture grouting not only blocks the rising channels of capillary water, but also forms a space frame with the bottom expansion micro-piles to bear the load with soil together, of about 50%. The reinforcement effect of the embankment by means of the Soletanche method is significant.