| In recent years,a number of high-concrete concrete face rockfill dams have been built at home and abroad.While gaining successful experience,some concrete face rockfill dams have large dam body deformation,squeeze and breakage of the faceplate,voids between the faceplate and cushion material,dam Problems such as large body leakage.In this paper,the measured data of Tianshengqiao first-level face rockfill dam is used to analyze the stress-strain law of the dam body,and a test plan is designed to study the impact of different dam filling methods on the vacant scale of the face plate,and then use the large-scale finite element analysis software ANSYS The stress distribution and deformation of the overall structure of the rockfill dam body have been refined and analyzed,and through the comparative analysis of different schemes,the influencing factors and laws of the stress and strain of the dam body have been analyzed.On this basis,the stress-strain distribution law of the concrete panel is analyzed,and the finite element substructure model of the panel is established.The stress-strain distribution law and influencing factors of the panel and its compression joints are obtained.Simulate the joints of the panel,analyze the improvement of the stress situation under different joint schemes,and propose engineering measures based on this.The main conclusions obtained in this article are as follows:1.During the storage period,the axial horizontal displacement of the dam showed a tendency to squeeze from the two banks to the middle of the valley.The maximum value of vertical settlement occurred in the middle of the dam body;The two banks gradually decreased;tensile stress appeared at the crest of the left and right bank slopes,and the concrete slabs were mainly tensioned.2.When the difference between the upstream and downstream rockfill modulus is large,it can cause uneven settlement of the upstream and downstream rockfills,and the deformation coordination is poor.Enlarging the range of the upstream rockfill area with better quality is beneficial to reduce the upstream and downstream deformation of the face rockfill dam body,and can reduce the squeezing stress generated along the axial direction of the dam;Effectively reduce the uneven settlement in the upstream and downstream rockfill areas,indicating that increasing the strength of soft rock canprevent excessive deformation of the dam.3.Enlarging the upstream rockfill area and increasing the strength of the downstream soft rock material can avoid large displacements of the dam body,thereby reducing the deflection of the panel,conducive to improving the stress condition of the panel,and helping to reduce the gap between the panel and the cushion material Friction,thereby reducing the squeezing or tensile stress of the vertical seam of the panel.4.The horizontal displacement of the dam in the axial direction and the horizontal displacement in the direction of the dam caused by the deformation of the rockfill inside the dam body can cause a large squeeze stress on the face plate.The panel has a contact rotation squeezing effect at the longitudinal seam,and a stress concentration effect is generated at the panel surface near the two sides of the seam,which is the main reason for the squeeze failure of the panel.5.The flood season-leveling construction scheme reduces the vertical height difference of the construction section,makes the dam body deformation relatively uniform,reduces the uneven settlement and the evacuation depth of the face plate,is conducive to the stability of the dam structure and prevents large structural damage of the face plate.6.Packing flexible materials at the joints of the panel can absorb the deformation energy of extrusion.The middle and upper parts of the vertical joint surface of the panel have large displacement of displacement,which is the part where stress is concentrated and is prone to squeeze failure.The soft and hard vertical joints are used to weaken the squeezing and damaging effect of the slab deformation. |
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