| Wandu Mountain City, the Ancient Koguryo relic located in Ji'an City of JilinProvince, is invaluable materials for studying Ancient Korean culture and history. Itwas listed as a National Key Cultural Relic Unit for Preservation and was listed on theList of World Cultural Heritage by UNESCO in 2004 at the 28th World CulturalHeritage Conference.The Watch Platform, studied in this thesis, is locates on a hummock at the northof the southern city gate of Wandu Mountain city and 200meters away from it. It isthe hathpace of the Wandu Mountain City for overseeing and guard. The remanet arewholly built by block stones. There are two stone-ladders at the inner side of theplatform. The exterior are intact regular block stones, and the interior are filled withrock blocks of various sizes and shapes.At present, the features of deformation of the Watch Platform can be generalizedas collapse, tensile deformation, convex camber of the wall, block stone failure, blockstone desquamation, settlement upheaval and bedstone inclination. Moreover, theWatch Platform sits on an inhomogeneous foundation. The west part of the structure ison the matrix directly and the east part of the structure is on the severely weatheredgranite stratum. Thus the stability of the platform and that of the groundwork arerelated closely. Besides, as the Watch Platform is built on a slope, it also has slopestability problems.In this thesis, the engineering geological condition has been analyzed;a great dealof data of engineering geological condition has been acquired through fieldinvestigation. Based on those fundamental research mentioned above, we concludedthat the main factor of the damage of the Watch Platform is differential settlement.The thicknesses of the soil stratum between the foundation base and the underlyingmatrix thicken from the northwest part to the southeast part of the Watch Platform.Thus, under the coupled action of the gravitational field and the seepage flow field,differential settlement occurred. During the process of consolidation settlement, thecascades slipped, collapsed and convexed. At the same time, as the settlementsbetween rock blocks are different, the tensile deformation, the outward motion and theintroversion occurred at the rock blocks, and the step surface lifted.Based on the field investigation and indoor test, the mechanical parameters,required for modeling, of the relative strata and building materials had been acquired.The numerical analysis had been carried through by using the FLAC3D software asbasic computation tool. The deformation features during the process of consolidationsettlement under the deadweight stress field, the effect, caused by the rainwaterseepage flow, on the deformation of the upper structure and the velocity features ofparticles under the dynamic load caused by earthquake. The mechanism of thedeformation and damage of the Watch Platform had been analyzed.Furthermore, the entire and local stability had been evaluated by using MSARMAmethod. The Watch Platform is stable under present status without the effect ofearthquake. The Watch Platform will be at the critical state when the seismic intensityis VII, and several parts of the upside will destabilize. |
