Study On The Calculation Model Of Side Pressure Of Viscous Particles Material

Bulk particles are widely distributed in nature and human life,such as the lateral pressure of soil on adjacent buildings,the lateral pressure of grain in silos on silo walls,and the lateral pressure of bulk cargo in open cars on their end walls or side walls.At present,the Rankine or Coulomb theory in geomechanics is widely adopted for bulk lateral pressure calculation.The numerical solution method of Coulomb theory has higher accuracy and wider application in solving active soil pressure,but the classical Coulomb calculation method is only applicable to cohesionless soil.The graphical solution method is also a commonly used method for solving soil pressure,which can adapt to a wider range of conditions and has a clear model,but has the disadvantages of complicated graphing and low accuracy.For cohesive soils,the presence of cohesive forces on the slip fracture surface makes it impossible to solve the lateral pressure directly using the Coulomb numerical calculation method.In this case,the lateral pressure of the cohesive fill can be solved using the graphical method,when the force polygon becomes a pentagon,making its solution process more complicated.In this paper,we consider that the main factor affecting the active earth pressure is the shear strength of the fill behind the wall.When the shear strength of the soil is high,the soil can maintain its own stability,and the active earth pressure is low;on the contrary,the soil has low shear strength and its own stability is poor,and the active earth pressure is high.Cullen shear strength equationτ₁=σtan?+c shows that the shear strength of soil consists of two components,namely friction strengthσtan?and cohesive strength c.In the soil pressure calculation problem,although the friction strength and cohesive strength affect the soil pressure calculation results in different ways,the trend of the results is the same,that is,the increase of both will make the active soil pressure decrease.Therefore,under certain conditions,we can equate the two,which is the starting point of this paper.If the complex lateral pressure calculation of cohesive fill can be equated to the lateral pressure calculation of non-cohesive soil fill,and its accuracy can meet the engineering tolerance error,it can provide a relatively simple and practical engineering calculation method,for which the main research contents and results of this paper are as follows.（1）In this paper,?and c in cohesive soil fill are equated to?_eq without cohesive soil,and the active earth pressure of this example is calculated by programming using the improved Kuhlman graphical solution method,and the error between the simplified method and the theoretical value is compared and analyzed,and it is found that it can meet the requirement of engineering error within 5%in the height range of 0.4h～0.425h,which proves that the simplified method is effective.（2）The simplified method was analyzed to determine the influence of each factor:c>?>H>γ>β>α>δ;The law of the best equivalent height is analyzed for each factor individually:the equivalent height decreases when the internal friction angleφincreases;the equivalent height decreases when the cohesive force c increases;the equivalent height increases when the sidewall height H increases;the equivalent height increases when the filler weight behind the wallγincreases;the best equivalent height remains the same regardless of the values of c,γand H,given that the value ofηis a constant.The optimal equivalent height was also explored for different combinations ofηand?,and the equivalent internal friction angle of cohesive soils was recommended for different levels ofη.