Analysis Of Uneven Settlement Of Pumping Station And Study Of Reinforcement Measures Based On Rheological Effect

Uneven settlement of buildings caused by soil rheology is one of the common problems in engineering field.China has a large number of pumping stations,sluices and other water conservancy buildings built on soil embankments such as the Yangtze,Yellow,Heilongjiang and Songhua rivers.During the operation of these projects,there are many failure cases of foundation settlement under the condition of neglecting soil rheology.Based on the present situation of uneven settlement of the factory building located on the gray silt foundation,this paper analyzes the influence of soil rheology on the underground factory building by using the methods of field observation and finite element analysis,puts forward the reinforcement measures to reduce the influence of soil rheology on the pump station factory building,and verifies the feasibility of the reinforcement measures.The research mainly includes the following contents:(1)According to the field test and data,the data obtained from the analysis are used to check the stability of the pump station structure,to judge that the pump station is in an unstable and dangerous state,to analyze the seepage field of the underground plant,to analyze the distribution and variation of seepage potential and seepage slope.(2)Combining the finite element method the three-dimensional finite element model of the underground powerhouse is established to study the influence of soil rheology on the uneven settlement of the underground powerhouse.The results show that the influence of soil rheology on the pumping station powerhouse can not be ignored during the excavation of the underground powerhouse.After considering the soil rheology,and according to the geological conditions revealed by the field inspection under the installation room,the soil model at the bottom of the installation room is selected as the finite element model to carry on the inversion calculation,and it is concluded that under the joint influence of 1,3# caisson pump room resonance,sand liquefaction and rheology,the 12# installation room inclines southeast,and the 23# installation room.tilt to the southwest,resulting in uneven settlement between the installation.After the foundation is strengthened,the stability of the foundation is improved greatly and the deformation is reduced.After the uneven settlement of the foundation,the soil rheology also intensifies the uneven settlement of the foundation.After the operation of the pumping station,the uneven settlement of the plant increases and has a further development trend.(3)According to the field inspection,the reinforcement measure plan is determined,and the reinforcement method of high pressure rotary jet grouting pile is adopted.The calculation results show that the foundation size is 8.4 m×6.8 m×20 m,and the rigid foundation size is6.8 m×6.8 and 2 m,pile length and diameter.At the bottom of the caisson,the depth of the model is 20 m..After 13 years of operation by finite element inversion and comparing the settlement of rigid foundation without pile and pile,the stress of plant foundation is reduced.The maximum displacement of soil without pile is 96.78 mm,the maximum stress of pile is3.054 MPa;the maximum stress of pile is 3.079 MPa.The maximum displacement after pile addition is 55.20 mm,occurs at the top and decreases by 19.76 mm.compared to 74.96 mm,without pile.The settlement value of pumping station without pile is much larger than that of pile after pile addition,which indicates that the method of high pressure rotary jet grouting pile can be effectively combined with the reinforcement measures of pumping station foundation built next to river and river,and it has obvious effect on reducing rheology to pump station factory building.