The Research On The Stability Of The Super-high Embankment Of Red-bed Soft Rock In Western Yunnan

Red-bed soft rock in western Yunnan is a kind of engineering properties of thespecial poor soil, which are widely distributed in a mountainous region of westernYunnan province. The highway construction steps of western Yunnan mountainousspeed up day by day as the great development to the smooth progress of the western.High filled embankment and super-high filled embankment have been acceptedgradually by engineers to cross steep slope and deep canyons area for the shortage fundrelative of mountain area highway construction. Adopting high embankment in themountain area highway construction not only can shorten the bridge mileage, eliminatea lot waster, balance roadbed, greatly reduce the cost of project,but also can protect theoriginal vegetation and cultivated land through less or abandoned building clay, witchaccord with the scientific concept of development and the building of a harmonioussociety thought. At present, the high filled embankment and super-high filledembankment have been everywhere in western Yunnan mountain area.On the basis of summing up previous studies, this paper focuses on theconstruction technology of high embankment relative to Red-bed soft rock in westernYunnan, and carried out researches on the deformation law and the stability of thesuper-high embankment on the transverse steep slope. Firstly, through the investigateand experimental analysis to study the feasibility of Red-bed soft rock in westernYunnan filling as the roadbed filling, the necessary parameters in slope stability analysiswere obtained. By establishing FLAC finite difference calculation model, this researchanalyzed the deformation law and the stability condition of the super-high embankmentunder the different embankment form, and studied the deformation law and the stabilityof the super-high embankment slope of Red-bed soft rock in western Yunnan indifferent rainfall strengths and rainfall durative times condition, the calculation resultsproved that the Red-bed soft rock in western Yunnan super-high embankmentprogrammed is feasible, and also verified the feasibility of Red-bed soft rock in westernYunnan filling as the roadbed filling. Secondly, the paper took secondary roads inShiDian~MengDing ShiDian~LianZi bridge super-high filled embankment as theengineering support, for the lack of stability of the original design, the studies proposedoptimization measures on super-high filled embankment slope in western Yunnan，including linear optimization, design optimization of slope, and other technical measures（resurfacing geo-grid, adding anti-slide pole board wall） to improve thestability of sub-grade, analyzing the deformation and stability with FLAC andcentrifugal model test, the results showed that after taking certain optimization ofreinforcement treatment measures can really improve the stability of long-termoperation of high embankment, also validating the feasibility of super-high embankmentinstead of bridge and Road performance of packing on Red-bed soft rock in westernYunnan. At last, relying on engineering geological environment and construction, thispaper described special optimization method, construction elements and attention forreinforcement design of high embankment on Red-bed soft rock in western Yunnan,selected the maximum height filling and most representative section of engineering asapplication, and took long-term observation for the high embankment, the observationresults anastomosed with the results of numerical analysis and centrifugal model test.The researchers of this paper will provide theoretical support and experienceguidance for super-high embankment instead of bridge and construction of high-filledembankment in mountainous area.This paper was sponsored by the science and technology project "The technicalresearch and projects demonstration of secondary highway construction with low costfor strong earthquake are in Yunnan mountain area" by Yunnan TransportationDepartment in the year of2011.