The Study Of The Side Friction Of Basement Exterior Wall In Loess Area

As the basis of the whole building design, the foundation design played a very important position and was directly related to the safety and engineering cost of the overall building whether it was safe, reliable, reasonable or not. Nowadays, the interaction between the soil and the wall of the underground structure was ignored in foundation design, just as a safety margin, which will not only lead to a waste of resources, also made the cost higher. In order to make full use of the interaction, this paper carried out relevant research in the theoretical contrast, the laboratory tests and the numerical analysis.First of all, the paper compared with the current calculation method of friction which commonly used, based on the special engineering properties of loess and the particularity of underground structure, determined the calculation methods that combining with earth pressure at rest and active earth pressure ultimately; Secondly, through combining with the laboratory test and the field test, drown a negative linear correlation between moisture content and the frictional resistance of the wall; Again, simulating the surface interaction between loess soil and underground outdoor wall by using the numerical analysis software ABAQUS, the paper got nonlinear distribution of frictional resistance in the horizontal direction and the depth direction; Finally, by calculating the total friction of the basement wall of the engineering cases, we can find that the total friction resistance value of double basement wall is equivalent to a whole layer load of the building.In this paper, theoretical analysis show that, the distribution of earth pressure on the wall of the underground structure is mainly based on earth pressure at rest and active earth pressure, we should combine with the both when calculating the frictional resistance; The experiment shows that, the increase of water content will reduce the friction coefficient of loess and concrete interface, it is particularly evident especially when it over the soil plastic limit and, it can increase the friction coefficient when increasing the pressure or density of the soil. Numerical analysis shows that, friction force of basement exterior wall along the depth direction nonlinearly, and the basement of the weight, size, elastic modulus, water content and soil density will affect the distribution of friction; Finally,by case calculation, we find that the total friction resistance value of double basement wall is equivalent to a whole layer load of the building.