Study On The Influence Test And Evaluation Method Of SDBS Solution On The Properties Of Red Bed Soft Rock

Red beds are widely distributed in areas such as southwest,south,central and northwest China.Lithofacies and physical and mechanical properties of red beds vary from place to place,but most of them are characterized by low compressive strength and easy to degrade and disintegrate when exposed to water,leading to high engineering construction and maintenance costs in red bed areas.How to effectively alleviate the disintegration and deterioration of red bed soft rock has become an important issue in engineering construction in red bed area.At present,our research group found that SDBS(sodium dodecylbenzene sulfonate)solution with low surface tension can inhibit the disintegration of some red bed soft rocks.Therefore,it is of great guiding significance for civil engineering construction in red bed area to further identify and evaluate its influence on the properties of different red bed rock types and their fillers.In this paper,laboratory tests on the properties of the red bed and its fillers under the action of SDBS solution were carried out at first.Then,based on the need of property assessment of the red bed soft rock,the evolution process of the red bed property under different conditions was studied by using the method of acoustic analysis.The main work completed is as follows:(1)Through the lithologic description of the original red bed rock provided by the site,combined with mineral composition analysis,the basic information of different red bed soft rocks is obtained.Based on theoretical analysis,the feasibility of SDBS solution to restrain the collapse of red bed soft rock was demonstrated and the reasonable concentration of the solution was determined.(2)The slake durability tests,wetting and drying cycle test,unconfined compression test,energy spectrum analysis and scanning electron microscope detection of three kinds of red bed soft rocks under SDBS solution were carried out.By comparing with the ones soaking in distilled water,the effect of SDBS solution soaking on the original lithology of typical red bed soft rocks was found out.(3)On the basis of the fractal theory,indoor scale samples were prepared to reflect the properties of field fillers.Triaxial shear tests and permeability tests under different confining pressures were carried out to find out the influence of SDBS solution on the strength and permeability of red bed soft rock fillers.(4)The percussion test of various rocks is carried out and the acoustic data of percussion is analyzed.The relationship between the characteristic parameters of rock percussion wave and its strength is established.Furthermore,percussion tests are carried out on typical red bed soft rocks that has experienced the action of solution immersion and humidity environment.Based on the relationship between rock percussion wave characteristic parameters and its strength,the percussion wave of red bed soft rock is analyzed,and the effect of SDBS solution on red soft rock properties is quantitatively studied.