Reinforced Experiment Research Of Yulin Acropolis South City Wall

Yulin Acropolis Is a rammed earth structure that lateral with brick, basically hasthe same form as the ancient city wall around the country, Yulin city wall was built in1437and before the1950the city wall is in good conserve. With the social development,Yulin city is in danger of extinct, the reinforcement protection is imminent.In this paper, through the analysis about the present damage situation of the citywall, obtain the damage factor,analysis to these factors demands a case that using theconsolidated soil to reinforce the city wall, the modified soil has a good durability. Themain contents of this thesis are as follows.1. To improve the intensity and durability of the soil, this paper first analysis thechemical composition of the wall soil samples, the research found the soil of city wallcontains a special local construction material called the LiaoJiang stone which is nativeto both the loess area of northern and northwest China, and regolith ofLimestone.Then,Chemistry analysis and salt dissolve analysis have been proceed, someamount of mixed stuff(liaojiang stone, cement, hydrated lime) were added into thesoil to improve the soil intensity, anti-water property, anti-salt dissolve property,anti-freeze property and anti-wind erosion property and so on.Make wall specimens in different mixture ratio to test moisture content and drydensity, optimum moisture content curve is obtained. Analysis the mechanism of actionbetween modified materials and soil; Following five tests have been completed:Unconfined Compressive intensity of specimens, Anti-Hydrochloric acid corrosiontest,Wetting test, rain drop erosion test and freezing-thawing cycle test.2. Analysis Soil failure mechanism under each experimental environment and themechanism of the effect which modified material improve the soil durability,following conclusions are obtained: A small amount of modified material influence compressive strength of soil a little. Cement proportion below10%will hardlyimprove the compressive strength of modified soil. Modified soil strength perform alinear relationship with addition of LiaoJiang stone and lime content. Cement soil canimprove the resistance to salt, water, scour resistance and freeze resistance performanceof soil. LiaoJiang Stone and lime improve the soil durability less than cement, largeamount of cement will make the soil to dark color and create mass white gypsumcrystals when under salt erosion, these effect the city wall’s appearance. fellow theprinciples of ancient building repair, the dosage of cement must be strictly controlledunder10%.3.This paper use ABAQUS finite element analysis software to analysis the seismicbehavior of city-wall, obtain the feasibility of reinforce the city wall with modifiedsoil and brick. Under the seismic load, The wall has good integrity when modified soiland soil combined well. Displacement and stress can meet the requirements.The research results demonstrated that rammed wall under (5%cement,5%hydrated lime,10%liaojiang stone,80%soil) has a well durability. On July27,2012,yulin occurred a torrential rains, research found that soil reinforced by modified soil isin good condition while other reinforcement wall in the region has a different degree ofdamage wall. Practice shows that the study meet with the actual situation well.