Study On Application Of CGMT Pile In Reinforcement Of Highway Foundation

CGMT (Cement Gravel Mixing Trenchless) non-excavation dry mixing cement gravel pile is a new pile based on gravel pile, CFG pile, and also has been used in Henan Highway disease treatment and embankment reinforcement project. The mechanism of CGMT pile composite foundation reinforcement is still being studied at present because of the complexity of geological conditions and CGMT pile itself. It studies on its reinforcement mechanism and optimal design theory through the methods of theoretical analysis, laboratory experiment, in-situ experiment.Firstly, through the research of the reinforcement mechanism on loose sand foundation and soft clay foundation, the reinforcing effect of CGMT pile can be obtained through vibration and compaction effect, replacement effect, the accelerated drainage effect and cushioning effect. Through the experiment and the analysis, we have obtained the pile-soil stress-strain relations of CGMT pile, the pile-soil stress ratio, the calculation methods of bearing capacity of single pile and composite foundation.Secondly, according to the study on deformation mode and the mechanism of CGMT pile, we can see that the accelerated drainage effect accelerated the consolidation of the foundation filling and reduced the settlement by improving the micro-structure of the soil around the pile. We put forward a reasonable settlement calculation method under the embankment load, and analyzed the influencing factors of embankment settlement.Thirdly, we did a lot of in-situ and laboratory experiments based on the reinforcement project of Jing-Zhu highway Xuchang-Luohe section. We test the treating effect, take study on bearing mechanism and stress-strain mechanism of complex foundation. At last, the strengthening effect is tested by geologic radar. Its feasibility and superiority of embankment reinforcement in Highway has been validated.The end, this paper introduces the construction and quality controlling and test of CGMT pile.