| Loose deposits mainly refers to mine exploitation, mountain pools excavation, building excavation, highway construction abandon soil, others are formed by landslip and debris flow in the nature. Loose deposits'slope possess loose structure, strong permeability, easy to be loose and be washed etc. engineering characteristics, which easily induced such as sloughing geological disasters under natural factors and disturbance of human activities. According to Henan Ye-Wu expressway loose deposits'slope mixed with expansive soil and with rich groundwater special engineering geology hydrological characteristics, and through the field survey, indoor and outdoor experiments, numerical analysis and entities project to build, failure characteristics and mechanism of loose deposits'slope mixed expansive soil in rich groundwater, the effectiveness of treatment with flexible supporting technology used in this special slope are studied:Firstly, Through progressing in-situ standard penetration test and field exploration research to the loose slope mixing expansive soil, loose deposits'are composed of gravel soils mixed expansive soil, which are loose, water softening, abundant groundwater, roadbed is seriously scoured by undercurrents. embankment slope prospecting shows, slope geological sections of the roadbed mainly are composed by perched water interface above and below of roadbed. Slope with characteristics of loose, rich groundwater, its'damage controlled by perched water interface, and with characteristics of shallow and tractional.Secondly, According related physical and mechanical properties experiments about loose deposit, obtain related physical mechanical parameters .Through the field measured the precipitation head viscous soil layers and loose slope of the permeability coefficient and conducted indoor wet under large direct shear test cycle, obtained the soil intensity with dry wet cycling times increase decay laws.Thirdly, finite element method for excavation seepage slope is simulated, and the results show that, with the slope of seasonal change of the dry-wet after lifting water loss ponds produced change, slope seepage path and seepage flow change. The higher the rainy season in water, slope dynamic water pressure, the higher the seepage flow is subsequently, the greater the slope safety coefficient criterion gradually become low; The dry season low water cases, slope soil mass in drier, seepage flow is lesser, underground water level is low, the influence of ground water on slope, slope safety coefficient weakened significantly higher than high water level. Analysis showed that only put mild rate cannot effectively firm geogrid body.Lastly, In recognizing rich groundwater expansive soil slope destruction stained the loose the occurring mechanism, characteristics and regularity, on the comparison and analysis of the retaining wall, soil nail and anchor rod class structures pile, traditional treatment such reinforcing method, combining with engineering slope and the advantages and disadvantages of using actual situation proposed geogrid, loose body directly as filling and complementary with perfect waterproof and drainage system of the flexible supporting structure of flexible supporting structure design, will loose the expansive soil slope slide collapse, stained repeatedly aquifers scour the roadbed engineering problems. Using the Finite Element Method to analyze the seepage change after the treatment of the slope, the limit equilibrium method for checking with the stability of the slope after the treatment. Calculation results verified the slope in a safe state after the treatment, and through work verified after testing, seepage slope evaluating. |
PDF Full Text Request