Study On Structural Behavior Of Interface Between Fresh And Old Concrete For Thickening Project Of Arch Dam

With the increase of service period and various damage of concrete structure，concrete reinforcement engineering has become an important branch in constructionfield. In the dam heightening project the problem of bounding between fresh and oldconcrete are one of the main difficult problem, with a large number of cracks andoriginal defects, the new-to-old concrete interface is vulnerable to destruction.Fracture problems and contact analysis must be studied for non-continuous structuralsurface.Interface of new-old dam will appear uncertain status such as opening, slippingand bounding. The interface is typical discrete structural surface, The fracturesituation and transfer mechanism of the interface is very complex, fracture and contactproblem should be taken into account in model simulation. In this paper,based on thethickening project of arch dam,we Combine the CZM with the contact analysis offinite element method software ABAQUS to simulate the mechanical behavior of theinterface and to evaluate the safety of arch dam.The numerical simulation analysis shows that the temperature load is the mainreason for the fracture of interface and the main influencing factor of the contact state.The interface of new-old concrete is always in the state of opening, and keeps bondingnear the dam foundation and abutment, at the same time, in the midst of dam, atransitional stage from micro-crack to full crack is found,in addition large openingdisplacement is found at the top of joint surface in the winter. The analysis shows thaton the one hand the CYJ-J1can modify the fracture situation of dam, on the otherhand, rebar-planting can decrease the opening displacement of joint surface.