Research On The Test Method Of Horizontal Thrust And Extrusion Method

The currently adopted spot in-situ test methods consist of large shearing apparatus, jack-up, horizontal thrust and extrusion method etc., with its own merits and defects. Among them, the horizontal thrust and extrusion method has characteristics of simple process, low cost and high efficiency, and is easier to carry out comparing with other in-situ test methods. But the current research of horizontal thrust and extrusion method still cannot meet the needs of the engineering, limiting its application in engineering.Coulomb’s earth pressure theory and Rankine’s earth pressure theory have become the classic theory of soil mechanics due to their clear mechanics concept and simple calculation, and are widely used in civil engineering. Rankine’s earth pressure theory hypothesis model is similar to the test model of horizontal thrust and extrusion method Therefore, Rankine’s earth pressure theory provides theoretical basis for improving the methodThis article points out its defects through the analysis of the related formula currently adopted by horizontal thrust and extrusion method. A calculation formula is created for horizontal thrust and extrusion test on the basis of the Rankine’s earth pressure theory. And with the basis of it, the test model and its test procedure are created for the indoor simulation horizontal thrust and extrusion test, with sand, the silt and mudstone as the objects and the formulas created by this article and current engineering calculating and analyzing separately its shear strength index, and the flowing result comparison of its result, the indoor direct shear test and small shear test. The research works out the test result’s relationship adopting the above different tests and calculation methods. In the end, it has been verified reasonably through the created formula’s application on practical engineering.