Application And Research Of Grouting Reinforcement For Existing Building Foundation

Compared with the foundation reinforcement treatment of the new building,the factors involved in the existing buildings are more complicated.Before the reinforcement and start at the beginning of design,first through to the building on the ground structures,underground structure and foundation bearing capacity for identification of scientific and reasonable,to identify the results as the basis to determine the necessity and feasibility of strengthening;secondly on the foundation for strengthening design,but also consider the coordination effect between the part and the underground part and the foundation of the building on the ground;in the formulation of foundation reinforcement design scheme,to consider the foundation is affected by the load effect,as little as possible the original soil disturbance;reliability in the construction process to ensure construction safety,be the leading technology,economy,applicability,safety and other aspects of purpose to the building.Engineering example of the No.5 building based on foundation reinforcement treatment,the paper mainly expounds the application of grouting in foundation reinforcement,and carries out the work from the following three aspects.(1)By consulting a large number of documents,the existing methods of foundation reinforcement and the engineering characteristics of various methods have been analyzed.By analyzing the technology and parameters of foundation survey,we find out the relationship between engineering test parameters and processing methods and the relationship between engineering parameters and stable settlement calculation.(2)Analyzing the theoretical basis of cement grouting method.The amount and filling rate of soil and the size effect of mud on pore are related.According to the influence of different grouting pressure on cement slurry,the roots permeate,break and compact the soil separately.The grouting theory of soil in soil under different action modes was analyzed.(3)According to the environmental conditions and topography of the foundation to be treated,considering the engineering mechanical characteristics and geological conditions,the grouting pressure and control method of grouting pressure are determined by means of test.Through selecting grouting material and proportion,grouting test,grouting parameters and grouting method,the foundation grouting reinforcement is designed.(4)According to the engineering design of foundation reinforcement of residential buildings,the grouting reinforcement and construction of residential buildings are carried out.Finally,the reinforcement effect is summarized.The effect of grouting reinforcement was tested by static load test.The final settlements are 62.64 mm,63.71 mm and 64.5 mm,respectively.According to the test data,the bearing capacity of foundation is determined to be 207 kPa.The bearing capacity of foundation after grouting meets the normal use requirements of the structure.