| This paper is relied on the National Natural Science Foundation of China "A new type of anchoring to strengthen the mechanism of ecological protection which protect the expansive rock and soil slope".Using the indoor model test to study the anti erosion performance of the high performance vegetation protection cushion system under the condition of rainfall in Nanning City, Guangxi. Based on the performance of HPTRM material, the expansive soil planting performance and making indoor model on expansive soil slope to carry out the artificial rainfall simulation experiment, study on anti scouring effect of expansive rock slope under protection of HPTRM system, so it can provide theoretical guidance for the field test of expansive rock soil slope and the application of HPTRM in the future. In this paper, the main research contents and conclusions included:(1) Experimental study on the properties of HPTRM materials. The test results show that the HPTRM intensity is high, which is more than 10 times of the Ordinary three dimensional network. and its elongation is small. HPTRM has a strong ability to resist radiation, and the durability is good, which service life can be as long as 50 years.(2) Indoor planting test. The results show that:under the condition of external temperature and humidity, the germination rate of ryegrass and dog tooth root was not affected by HPTRM net, and the vegetation growth was slightly worse than that of bare slope; Directly planting on the surface of expansive soil is not conducive to vegetation growth; After 45 days of vegetation growth, the 10cm depth range of the slope surface is measured, and the content of HPTRM vegetation protection slope and the pure vegetation protection slope are basically similar, which is about 0.14%.(3) Expansive soil with plant roots, the specimen shear stress and the vertical stress is proportional to the relationship. The change of the content of the expansive soil samples and the water content of the soil samples have a direct influence on the shear strength of the expansive soil samples.(4) By using a portable automatic manual simulation of rainfall equipment to simulated natural rainfall, and analysis of the effect of anti scouring effect of HPTRM protective expansive soil slope under different influence factors (rainfall intensity, rainfall duration, slope gradient, etc.). The text results show that, the size of the unit time slope is determined by the intensity of the rainfall, the second is the size of the rain drops, and the gradient of the slope.(5) Comparative study on different slope ecological protection measures. The results show that under the same conditions of rainfall, expansion rock slope surface erosion amount is mainly determined by the slope protection, the size of the unit time erosion amount is as follows:bare slope> HPTRM protection slope> vegetation protection slope> Ordinary three dimensional vegetation protection slope> HPTRM vegetation protection slope. Compared to bare slope, HPTRM slope protection at the level of the rainfall is moderate rain or heavy rain, reduced by 70%～85% of the erosion; and HPTRM vegetation protection slope under different rainfall intensity erosion, the erosion amount is very small, the erosion amount is only about 1% of the bare slope. It shows that HPTRM can effectively reduce the slope erosion, and the effect of anti-erosion after the combination of vegetation is more obvious.(6) Monitoring the change of water content in the process of simulating rainfall. The maximum amplitude of the content daily variation below the 5-11cm of HPTRM vegetation protection slope is about 4%, far less than the daily water content change of bare soil slope. HPTRM vegetation protection slope in the slope below the 5-11cm range of the maximum amplitude of the daily variation of water content in 4%,. The water content in the top is lower than the toe. The change of water content in the slope of 20-40min was the fastest in the process of 1H simulation. |
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