Research On Rectification Scheme And Deformation Analyzing On Tower Foundation Of Chongsheng Temple's Three Pagodas In Yunnan

Ancient pagoda all over the country is one of the carriers of 5 thousand civilization history in China. Chinese pagoda is an outstanding representation of ancient high buildings, which syncretizes the elites of Chinese traditional architectural art and external culture. The existent ancient pagodas not only have the precious cultural heritage value, but also have highly sightseeing value. However, these pagodas had experienced many vicissitudes of life, suffered much artificial and natural breakages such as war, earthquake, weathering, so, majority of them are need to be repaired and strengthened imminently. Along with the progress of social civilization, the people have been paying more attention to the protection of ancient buildings, and research for the pagodas has already become an important task of historical building protection and city construction. The developing modern technology is also promoting the protective work to change over to the science stage from the experience stage.Many ancient buildings has been situated in some inclination because of the limitation of the ancient building technology and the demolish during thousands of years. Especially, the pagodas with brick masonry structure are very sensitive to the foundation conditions, and once they incline, it will be resulted in concentration of the foundation stress of the inclined side and further accelerations of the buildings, because their ratio of length to diameter is very large, and their centers of gravity are high, adding that they have large dead weights and low strength. The brick masonry pagodas in our country now are all with different degree inclination, and some ones with excessive inclination have collapsed.Chongsheng temple in Dali of Yunnan province built up in Nanzhao period of Tang dynasty, was the famous stupa of south-west area as the royal temple of Dali Kingdom in Nanzhao period. Chongsheng temple three pagodas was built 1200 years ago, which was one of the ancient building groups which were preserved intact. Acrossing rains and winds for thousands of years and countless of earthquakes, two of the tower foundation of Chongsheng temple three pagodas have occurred uneven settlement, and the tower body has departured the perpendicular bisector and been in an anxious situation of inclination. The determinant of the stability,the actuality and inducing factors of the disease and the developing trend of them have been the problems crying for being solved.The paper relying on the protection engineering of the Chongsheng temple three pagodas in Yunnan Dali and taking the south and north turret which inclined significantly as the main research object, discussed the mechanism of uneven settlement of the brick masonry pagodas on the base of finding out the actuality and inducing factors of uneven settlement, and simulate and analyze the stress-strain of ground and foundation of south and north turret and the deformation law of tower body under the condition of uneven settlement by theoretical calculation and ANSYS software of finite element analysis. The paper also suck the characteristics and rules of the settlement and inclination and summarized the common principle of rectification and reinforcement and the applicability of the technique. And in the end it put forward the advice on the protection of three pagodas and provided the scientific basis for the protection of the ancient building group of the three pagodas.The main research results are as follows:1,The paper analyzed and summarized the main reason,actuality and the fruit of rectification and reinforcement, and inducted the common solutions of rectification and reinforcement of the brick masonry pagodas. It also supplied theoretical basis for the analysis and study of the upper project of rectification of the south and north turret of Chongsheng temple three pagodas by investigating different deviation rectification technology and analyzing themechanism of inclination of the ancient pagoda.2,The study results indicated that the inclination of the south and north turret was related with the uneven settlement of the ground. The author used the classical calculation theory requested by the criterion to calculate the settlement of foundation of the feature points in different working conditions. And the results shown that the inclination caused by the uneven settlement of the north turret occupied 41.57% of the whole inclination, and the south one occupied 32.90%. There are three factors studied in this paper which influence the uneven settlement of the foundation, and the inhomogeneity of the ground soil layers is the main factor which occupied 66.46%and 68.33% of whole inclination of the south and north turret, the next factor is the horizontal wind load occupying 24.51% and 22.84% of the inclination, the factor having the smallest influence on the uneven settlement is the seismic load.3,The paper simulated the factors influencing the uneven settlement of the foundation with ANSYS by building three-dimensional simulation model, and analyzed the law of the stress and strain, drawn a conclusion that the inclination of the tower body was caused by the most deformation of the weaker soil of silty clay layer bearing the load of the tower and overbite cushion which caused uneven settlement of the foundation. In addition, it simulated and analyzed the plastic deformation zone of the south and north turrets. In the end, the paper drawn a conclusion that finite element method was more consistent with actual situation for it took the boundary conditions,the character and inhomogeneity of the complicated material of rock and soil mass.4,By checking the inclination of the south and north turrets in Chongsheng temple , a conclusion was drawn that the formation index of the base of the south and north turrets was over standard regulated by the criterion and it needed to be rectified and strengthened.5,On the base of the analysis on the applicability of the rectification project in common use and according to the geological condition of the field, the author proposed that the rectification and reinforcement of the two turrets should focus on the reinforcement of the soft foundation to slowdown or stop the uneven settlement along the most inclining direction. In the end, three schemes were put forward to strengthen the field. And the project considered first to apply was root pile to strengthen adding anti-seepage and drainage of the ground surface. The study result of this paper supplied theoretical basis for the upper protection work of rectification and reinforcement.In this paper, the innovative points are as follows:At present, there was very little research on the stress-strain appearance and deformation of the ancient masonry pagodas and the tower foundation by established 3D entity model with the finite element method. Moreover, the research on differential settlement deformation and anti-dumping corrective reinforcement of the south and north tower in Dali was still a blank space. The paper relying on the protection engineering of the Chongsheng temple three pagodas in Yunnan Dali and taking the south and north tower which inclined significantly as the main research object, discussed the mechanism of uneven settlement of the brick masonry pagodas on the base of finding out the actuality and inducing factors of uneven settlement, and simulate and analyze the stress-strain of ground and foundation of south and north tower and the deformation law of tower body under the condition of uneven settlement by theoretical calculation and ANSYS software of finite element analysis. The paper also suck the characteristics and rules of the settlement and inclination and summarized the common principle of rectification and reinforcement and the applicability of the technique. And in the end it put forward the advice on the protection of three pagodas and provided the scientific basis for the protection of the ancient building group of the three pagodas.