W dolnych pomostach budynku parkingowego na południu Niemiec wystąpiły patologicznie duże ugięcia. Zjawisko to utrudniało odprowadzenie zanieczyszczonej wody po myciu pomostów, co zakłócało ich użytkowanie, a nawet trwałość. Firma wykonawcza obwiniła za to projektanta utrzymując, że podciągi są zbyt giętkie, a ubezpieczenie tego ostatniego zleciło autorowi wyjaśnienie przyczyn awarii. Zaawansowana analiza konstrukcji wykazała, że winę ponosi wykonawca, który podpierał poszczególne szalunki ze świeżym betonem tylko na jednym pomoście. Udowodniono to drogą nieliniowych analiz pomostów z uwzględnieniem spadku ich sztywności wskutek zarysowania i pełzania betonu.
EN
The lower piers of a parking building in southern Germany experienced pathologically large deflections. This phenomenon impeded the drainage of contaminated water after washing the piers, which interfered with their use and even durability. The contractor’s company blamed the designer for this, maintaining that the stringers were too flexible, and the latter’s insurance company commissioned the author to explain the causes of the failure. An advanced analysis of the structure showed that the contractor was to blame, supporting individual formwork with fresh concrete on only one platform. This was proven through nonlinear analyses of the piers, taking into account the decrease in their stiffness due to cracking and concrete creep.
Concrete hollow thin-walled high piers (CHTWHPs) located in mountainous areas may be destroyed by the huge impact force of accidental rocks. The study focuses on analyzing the effects of rock impact on the pier, including its impact force, pier damage, dynamic response, and energy dissipation characteristics. The results show that: (1) Increasing the impact height led to a decrease in the peak impact force. Specifically, 15.5% decrease in the peak collision force is induced when the height of rock collision rises from 10 m to 40 m. (2) The damage mode of the pier’s collision surface is mainly oval damage with symmetrical center, radial damage on the side surface, and corner shear failure on the cross section. (3) The peak displacement of bridge pier increases with the increase of collision height. As the collision height increased from 10 m to 40 m, the bridge pier’s peak displacement also increased, rising by 104.2%. (4) The concrete internal energy gradually decreased with increasing collision height, dropping by 36.9% when the height of rock collision rises from 10 m to 40 m. The reinforcement internal energy showed an increase of 78%. The results of this study may provide reference for the rock collision resistance design of CHTWHPs.
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