Frost Heaving Damage Of Concrete Lining Fracture Mechanics Model And Numerical Simulation Research

The growing shortage of water resources has become the bottleneck problem affecting theglobal socio-economic development, since the reform and opening up, with the developing ofeconomy for our country society, the contradiction between water supply and demand havebecome increasingly prominent, the establishment of water-saving society, the development ofwater-saving agriculture potential in the pipeline. China is a large agricultural country, in thenorth of seasonal frozen in permafrost regions, the construction of a large number of canalseepage, but due to the channel concrete lining defects in the materials and Drainage permafrostheaving role, channel concrete lining heaving damage suffered to varying degrees, in addition toexist the body cracks of the concrete lining of the initial crack occurrence, development andfailure process often occurs under the action of the frost heave force, making the channel losessignificance of seepage, resulting in the maintenance and management of irrigation area increasein the cost of capital investment increases, seriously affecting the effective play of the waterconservancy project, which restricts the healthy development of the irrigation canal seepagecontrol works. The major factor is not adequately recognize the initial imperfections of theconcrete lining material and drainage frost heaving of law, the most impermeable liningengineering design, does not consider the interaction between frozen in the the Canal Foundationpermafrost channel lining body The expansion under concrete lining Fracture law and itscharacteristics. Therefore, in order to prevent the channel concrete lining frost heave damage, inaddition to the temperature change of the surface of the concrete lining in research outside solarradiation influencing factors, must also be studied under the action of frost heave channelconcrete lining the Fracture law of.In this paper, on the basis of the access and analyze large amounts of literature, mainly forthe following research:(1) Through appropriate simplifications and assumptions, and establish a high water table,trapezoidal channel frozen mechanical model, combined with the conditions of the cracking ofthe concrete lining board, the internal forces of the different locations, Splitting location and aseries of calculation method, and the mechanical model, and based on this model gives a highwater table, trapezoidal channels for Best Hydraulic Section.(2) On the basis of linear elastic fracture mechanics, combined with the existing channelconcrete lining frost heave structural mechanics model, consider frost heave force, reasonableassumptions and simplifications, the concrete lining plate fracture as a (Ⅰ+Ⅱ) complex crack propagation problems, the establishment of channels shady, sunny and channel bottom threedifferent locations of concrete lining plate the frost heave fracture mechanics model for channelconcrete lining board the frost heave fracture mechanics failure criterion and concrete liningthickness design. The use of this frost heave fracture mechanics model not only can calculate thethickness of the concrete lining in the shady, sunny and channel bottom plate reasonableexamples show that the channel concrete lining frost heave fracture mechanics model is in linewith the actual effective method for practical engineering.(3) The channel slope plate and bottom plate simplified by the triangular distribution pointbending under the load and uniformly distributed loads, the use of the generalized theory offracture mechanics and permafrost mechanics calculated under a certain thickness slope boardand backplane allows frozen deep, established on the basis of fracture mechanics-based concretelining frost heaving fracture prediction model; while the temperature factors fracture mechanicsmodel is introduced to calculate the critical temperature drop of the crack propagation channellining in different parts of the body, using MATLAB programming deduced showing therelationship between the temperature drop and the stress intensity factor, which made thedifferent parts of the concrete lining of a calculation channel allows deep freeze calculate newapproaches and concrete lining the frost heave fracture critical extended temperature criterion.(4) The introduction of the fatigue crack growth of the Paris Law channel concrete liningboard, fracture mechanics model and linear elastic fracture mechanics theory of frost heave, useof fracture mechanics theory and methods for different parts of the channel concrete lining boardservice life analysis, given the estimated life of the concrete lining plate the frost heave fracturemechanics analysis formula. Combined with the extended finite element method, the use ofgeneral-purpose finite element software ABAQUS the initial crack concrete liner cracks underthe action of frost heave force open process was simulated to verify the correctness of theformula.