Static And Dynamic Analysis And Research On Cracking Principal For High Arch Dam

Arch dam is an important type of dam. It is an economical and safe type of dam.The advantages of arch dam are very conspicuous for high dam. It is adopted widelyin domestic and foreign high dam for its graceful figure and reasonable structure.Arch dam is researched in this paper and stress and displacement of high archdam under basic loads are analyzed with concrete constitutive relation adopted byelastic and nonlinear conditions. The results indicate that biggish tensile stress appearsin heel area of high arch dam under elastic condition. Tensile stress value exceedsconcrete strength of extension so cracks come into being in dam heel inevitably.Cracking is an important problem needing to considered in high arch dam design.It is believed that compressive strength of arch dam with general height has largesafety stock, when crack happens partly, dam body stress can adjust by itself andnormal work is not affected. However stress level is very high and safety stock isquite little for high arch dam with 300 meters height, the room for stress adjustment isnot adequate once tensile crack happens. Cracking of high arch dam is analyzed andcalculated in this paper aim at this situation and cracking trace is carried out oncracking elements simultaneously. In process of cracking trace, the least reliabilitymethod is adopted. Response surface and first-order second-moment are utilized forreliability calculation. This method is more effective and simpler than other methodsfor the solution of implicit reliability calculation of massive structure, so it is worthyof generalization.Seismic factor is a part which cannot be ignored out of question in high arch damdesign and calculation. The earthquake resistant ability of a project is a key to assureits safety. Dynamic analysis is carried on high arch dam by both elastic and nonlinearmethods in this paper to calculate the stress and displacement of arch dam underseismic load. In the same time, cracking trace under dynamic condition is completedon arch dam which is analyzed by nonlinear method to study crack after tension andclosure after crack of concrete material of high arch dam applied both by dead andseismic loads. The analysis indicates permissible crack of dam heel should beconsidered as a design condition for the high arch dam which cracks in heel providedthat crack divergence is stable. If impervious drapery is not damaged, this crack willnot endanger integral safety.