Research On The Disease Cause And The Rectification Reinforcement Technology Of The Pagoda In Huan County

The Huan County pagoda which is nearly one thousand years history of the song dynasty is the national key protection of cultural relics.It locates on famous Ling Wu ancient stage in the eastern part of Gansu province,the total height of the pagoda is about 28.7 meters.It is imitation wood brick pagoda with dense eaves and is five layers eight surfaces.There are wooden ladders which can pass though the top of the pagoda and there is a door in each interval,which can be seen in distance.The pagoda which is majestic tall and is exquisite has the high architecture,art,culture,and scientific research value.After all,the Huan County pagoda has endured nearly one thousand years of wind and rain erosion and also produced a variety of disasters.The pagoda has inclined 13.29 ‰ towards to southeast.It is more than three times than the national standard value.Pagoda spire inclination rate is about 25 ‰,the pagoda became a veritable dangerous pagoda.Especially the fear is that the tower inclined disaster is increasingly intensified and became more and more worse,once encounter an earthquake or a storm,the pagoda is in danger of collapse all the time.The following work is carried out on the basis of the disease control project of Huan county tower :(1)Consulting a large amount of data,discussing the present situation at home and abroad in ancient pagoda,the history of ancient pagoda in China,the history of the tower of Huan county and the previous repair and strengthening.Collecting and analyzing the successful cases of the rectification and reinforcement of ancient pagodas at home,and summarizing the reasons for the tilting of buildings and the present commonly used methods for rectification and reinforcement of buildings.(2)Using the UAV aerial photograph to make a full mapping of the Huan county tower body and its surrounding environment,and make the 3D model of the Huan county tower,get the exact size of the tower body,and calculate the weight and the height of the center of gravity of Huan country tower.Using the aerial mapping of Huan county tower orthophoto map and the total station fitting center to measure the inclination.The two methods check each other accurately and accurately measure the tilt rate,offset,tilt and inclination of the Song tower of Huan county,get the basic situation of the ancient pogoda and correct the mistakes in the previous archives..(3)The detailed engineering geological survey of the Song Pagoda in the Huan county is carried out.The form of the tower body and the basic structure,the ground geology and the bearing capacity and the occurrenc form of groundwater are grasps.The deformation status of the ancien pogoda is analyzed.The excavation pit in the inclined direction both the less sinking side and the more sinking side is against the tower body(the excavation depth should penetrate the artificial rammed soil layer until the old stratum),and sampling and take soil test.According to the test results,the water content and the compression coefficient of the soils on both sides are compared to find out the six main points of disease and tilt.The reasons include : 1)The influence of ground treatment difference;2)The influence of water content difference;3)The influence of loess collapsibility;4)The influence of the difference of ground soil density;5)The influence of the difference between the foundation and the shear strength;6)The influence of the earthquake.(4)In view of the six main reasons,the paper puts forward the rectification scheme for the core technology of the ground ring beam to change the foundation of the tower of Huan county,to excavate soil,force sedimentation and rectify the ground in the less sinking side of the tower of Huancounty(the horizontal drilling or the rope saw cutting),and to set up the anchor static pressure pile to reinforce ground of the more sinking side,steel pipe piles and lime piles are used to reinforce the foundation outside the tower.In order to ensure that the whole body of the tower body is not damaged during the rectification and reinforcement,the protection measures of the tower rope pull rope are formulated.At the same time,in order to prevent the phenomenon of "sudden sinking" in the process of soil correction,the protection measures of the positioning pier combined with the jack support are set up under the foundation of the underpinning tower so as to ensure that the whole rectification and reinforcement process is no danger of anything going wrong.