Study On The Safety Of Light Tamper Compaction In The Special Position Of The Highway Bridgehead And Culvert

Express highway Bridge Abutment Traffic Jump has a great influence on the safety and comfort of driving, the basic reason is that the compaction does not conform to the standard in the special position of the roadbed, such as bridge-head、culvert-back, causing the uneven settlement. Light Tamper method is an important method to reinforce compaction of bridge-head and culvert-back, the uneven settlement gradient can slow down by tamping, so the structure and roadbed can be transition smoothly. During the construction process, the shock vibration of Light Tamper inevitably influences the stress and deformation of the adjacent structures, or even damages the structures. The paper researches mainly the impact caused by Light Tamper on bridge-head and culvert-back;Firstly, the paper analyses tamping reinforcement mechanism, the propagation principle of tamping energy and impact mechanism on construction, and proposes a method to assess the safety of the construction; Secondly, the discrete element simulating software(PFC2D) is used to calculate and simulate analysis, the effect of the dynamic tamping on the structures( for example, bridge and culvert) is measured by changes of the horizontal stress and displacement during the process of dynamic tamping on the structures, and adopt the displacement and stress-strain assessment method to assess the safety. Finally, Through the site experiment, test the changes of the strain and displacement of the structures during the construction process of Light Tamper, analysis the change regulation of horizontal displacement and strain distribution under the circumstances of different tamping horizontal distance and tamping times, and then assess the safety of Light Tamper construction combining with the domestic and foreign indicators or methods on the safety assessment of the structures.