Study On Compressive Behavior And Engineering Application Of Geocell Structure Layer

This paper takes the embankment of bridge abutment transition section in coal mining subsidence area as the research background.Based on the characteristics of the coal gangue decay over time,the effects of various factors on the compression behavior of geosynclinal structure layer and the interaction between the coal gangue and geosynclinal material were studied by numerical simulation.Through numerical simulation,the influence of geocell compartment spacing,geocell compartment layer number and geocell compartment height on the settlement of embankment in the transition section of subsidence area is analyzed,and the reinforcement form of geocell compartment is reasonably optimized.The feasibility of strengthening the embankment of the transition section with geotechnical grid is judged according to the engineering practice.Specific research results are as follows:(1)After geotechnical cell reinforcement,the vertical variable of the structure layer decreases and the deformation modulus increases.With the increase of decay time,the fine material content of coal gangue increases,the vertical deformation first decreases and then increases,and the deformation modulus first increases and then decreases.When the coal gangue decays for two months,the geotechnical lattice structure has the strongest deformation resistance.(2)The height of geocell chamber is inversely proportional to the vertical deformation of the structure layer and proportional to the deformation modulus of the structure layer.The geosyncline weld distance is proportional to the vertical deformation of the structure layer and inversely proportional to the deformation modulus of the structure layer.When the geotechnical cell of 200-400 is used,the deformation modulus and the percentage increase of deformation modulus of the structure layer are the largest in this case,respectively 63.74 mpa and 25.72%respectively,and the geotechnical lattice room has the best reinforcement effect.(3)After the construction,the structural layer is in the state of full water due to the rainy season or the rise of underground water level,and the anti-deformation capacity of the structural layer is obviously less than that of the structural layer under the optimal water content.In engineering,vibration compaction should be carried out near the optimal water content to ensure the deformation resistance of geocell structure layer.The deformation modulus of the structure layer increased greatly after the geotechnical chamber strengthened coal gangue with saturated water content,andthe percentage of increase was within the range of 38.66%~58.64%.(4)Under the load,the lattice room displacement and the maximum film stress are the largest,and the farther away from the load position,the smaller the lattice room displacement and the maximum film stress are.With the increase of load,the displacement of cell and film stress increase.The stress of cell membrane can reflect the reinforcement effect of geotechnical cell.(5)For the soft soil section in the coal mining subsidence area,geosynclinal embankment reinforcement can effectively reduce the embankment settlement in the transition section.For each additional two layers of grille,the embankment settlement decreased by about 0.5cm.When the number of grid-compartment layers is 3~7 layers,the embankment of the transition section can be strengthened with five or seven layers of geotechnical compartment.The interstitial section embankment is strengthened with the interstitial section embankment of 70 cm interstitial section embankment.The height of lattice chamber has a great influence on the embankment settlement.It is suggested that the geotechnical chamber with the height of 200 mm should be used to reinforce the embankment in the transition section.There are 109 figures,30 tables and 85 references in this paper.