Method for determining allowable bearing capacity of railroad bed

Abstract

According to the method for determining the allowable bearing capacity of the railroad bed, the allowable bearing capacity of the railroad bed foundation can be accurately determined according to the stability safety coefficients required by different grades of railways, and the design is more accurate. Comprising the following steps: (1) determining the thickness, weight, cohesive force and internal friction angle of a ground stratum; (2) determining a stability safety coefficient [Fs] to be reached by the roadbed according to the designed speed v per hour of the railway; (3) giving an initial value and a load width B of an embankment base load p; (4) calculating the stability coefficient Fs of the embankment and the foundation under the action of the load p; (5) gradually increasing the load p of the substrate, and repeating the step (4) until Fs is less than 1.0; (6) drawing a relation curve of the substrate load p and the stability safety coefficient Fs; and (7) determining a base load [P0] corresponding to [Fs] on the relation curve of the base load and the stability safety coefficient, namely the allowable bearing capacity of the railway roadbed foundation.

Description

technical field [0001] The invention relates to the technical field of railway subgrade structures, in particular to a method for determining the allowable bearing capacity of railway subgrades. Background technique [0002] As the substructure supporting the upper track, the railway subgrade has clear requirements on the settlement, stability and bearing capacity of the subgrade and foundation in order to ensure the smoothness of the line and the safety of operation. [0003] Railway subgrades belong to flexible foundations, while general building foundations belong to rigid foundations. The bearing characteristics of flexible foundations and rigid foundations are significantly different. The bearing capacity of flexible foundations is greater than that of rigid foundations, so the calculation of bearing capacity is also different. [0004] At present, the calculation idea of ​​bearing capacity in "Technical Regulations for Foundation Treatment of Railway Engineering" is as...

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Problems solved by technology

[0005] (1) The allowable bearing capacity is determined artificially using the bearing capacity correction factor, the concept is not clear, the theoretical basis is not sufficient, and there are disputes in the actual use process;

[0006] (2) The increase value of the bearing capacity of the flexible foundation is related to the grade of the railway and the nature of the foundation soil. The higher the grade of the railway and the higher the operating speed, the greater the required stability safety factor and the smaller the corresponding bearing capacity correction factor; The better the soil properties, the smaller the value of the bearing capacity correction factor k. The value in the "Technical Regulations for Railway Engineering Foundation Treatment" only stipulates the range of 1.2 to 1.5, but it has not been refined. When determining the allowable bearing capacity of the railway subgrade, it depends on the design The correction coefficient is determined by the experience of personnel, which is highly subjective and not accurate enough

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