| With the development of infrastructure in China,the experience of infrastructure construction is becoming more and more prosperous,and the demand for land is becoming more and more tense.Therefore,more and more hilly and mountainous areas are used to build houses,but due to lack of corresponding treatment experience and theoretical support,it brings more difficulties to the construction.Taking a bad geological factory building in Mianyang mountain area as an example,this paper puts forward the geological treatment scheme of the awful mountain area,as well as the subsequent monitoring and evaluation.The paper carries on the research in the following aspects,and obtains the following results:(1)The engineering site is situated on a river overlying area of Pingwu County,Mianyang City.The settlement of the project site is generated by the preliminary code method that the 227.9mm is greater than the maximum value of the design,and the design elevation is 4 m higher than the natural standard,so the foundation treatment must be undertaken.(2)Depending on the actual situation,it is therefore proposed adopting well point precipitation and large area excavation backfill dynamic compaction treatment.For the calculation of well point precipitation,255 water well pipes are used for precipitation treatment.Depending on the actual situation on the spot,it is determined that the ratio of soil to rock is 6:4.For the dynamic compaction treatment,four in-situ test areas are chosen according to the actual situation in the field.Finally,we select the tamping hammer mass of 15 t,the tamping diameter of2 m,the height of the tamping falling point of 12 m,the tamping point spacing of 5m,and the tamping energy level of 2000 kN.m.(3)Unsaturated characteristics of the backfill are studied,and the relationship between the matrix suction and water content of the backfill is considered under the action of different matrix suction.Unsaturated SWCC characteristics of the backfill prove that the backfill is unsaturated.(4)By numerical simulation of the excavation process and the foundation after treatment,it can be seen that the excavation in the sub-region has a great influence on the adjacent areas,and the settlement is about 266 mm before treatment,and about 117 mm after foundation treatment.(5)The settlement calculation of the treated foundation is performed by utilizing the standard method and the unsaturated soil settlement method.The settlement of the foundation is about 97.01 mm and 66.8mm,respectively.It can be observed that both of them meet the design requirements,and the calculated data of unsaturated settlement theory and the actual monitoring data about 70 mm are more in line with the actual situation.(6)According to the actual monitoring work after foundation treatment,the settlement is about 70 mm.Through the improved BP neural network prediction,final settlement data 72.03 mm in the next three years is achieved,which further proves that the foundation treatment method is reasonable and reliable. |
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