| The Golmud-Korla Railway starts from the west of Golmud City in Qinghai Province to Korla City in Xinjiang,with a total length of 1214 km.It has opened up the rail transit from the central part of Qinghai to the central part of Xinjiang,perfecting the railway transportation network in the western part of China,and promoting the social economy and national unity in the area where the line is promoted.The development of the region from the Mainland to Central Asia,Southern Europe and other Belt and Road areas has important strategic significance.The Qinghai section of the Geku Railway is 505 km in length.The area along the route belongs to the Qaidam Basin on the Qinghai-Tibet Plateau,with an average elevation of about 3000 m.The area along the line belongs to the Qaidam Basin.It is a typical plateau continental arid climate with less precipitation,large evaporation,deep groundwater,sparse vegetation,and complex and diverse types of aeolian landforms.Under the action of strong winds,wind-blown sand is easily formed,which has a great destructive effect on the railway(Subgrade,bridge,culvert,etc.).Therefore,the sandstorm disaster has become the primary problem facing the safe operation of the Qinghai section of the Golmud-Korla Railway.In this paper,field observation,field monitoring,wind tunnel test and numerical simulation were used to clarify the wind field characteristics and typical surface sand flow movement laws in different areas along the Qinghai section of the Golmud-Korla Railway,and screen the suitable suitable for the Golmud-Korla Railway Qinghai.This study determines the optimal protection characteristic parameters of sand-proof material,evaluates the protection benefits of the sand-proof engineering test section,and improves and optimizes it to construct a sand-control system model suitable for the characteristics of sand-sand disasters in the Qinghai section of the Golmud-Korla Railway,it provides favorable support for the design of the railway project's sand control system.The main conclusions are as follows:(1)Based on the difference of aeolian landform types and underlying surface properties along the Qinghai section of the Golmud-Korla Railway,the sand-sand environment of the Qinghai section of the Golmud-Korla Railway is divided into three types: the mobile dune area,the gravel Gobi area and the lake basin desertification area.(2)The annual average wind speed in the mobile dune area(Zhongzaohuo)is 5.1 m/s,the maximum wind speed is 21.2 m/s,the dominant wind direction and the main sand-driving wind direction are WNW,W and NW,and the sand drift potential(DP)is 452.07 VU is a high wind energy environment;the average annual wind speed in the gravel Gobi area(Gansen)is 3.6 m/s,the maximum wind speed is 16.4 m/s,and the dominant wind direction and main sand-driving wind direction are WNW,NW and W.DP is 223.56 VU,which belongs to the medium wind energy environment;the annual average wind speed of the lake basin desertification area(Mangya Lake)is 4.4 m/s,the maximum wind speed is 20.6 m/s,and the dominant wind direction and the main sand-driving wind direction are NW,N,and NNW,the DP is 311.18 VU,which belongs to the medium energy environment.(3)The results of sandstorm observation show that the flux of sand transport on the three types of landform gradually increases with height,and the structure of sand flux obeys the law of exponential decline.Affected by the regional wind energy intensity,the sediment transport in the mobie sand dune area and the Mangya Lake basin is mainly concentrated in the 2 m height above the surface of the earth.The sand particles in the sand flow are dominated by fine sand,mostly belonging to the saltating particles;The sand transport in the Gobi area west of Mangya Lake is mainly concentrated in the height of 1.5 m above the surface of the earth.The sand particles in the sand flow is dominated by fine sand,and most of them belong to the saltating particles.(4)The protection effectiveness of HDPE board fence and galvanized metal sheet(punching board)fence was evaluated by wind tunnel test and numerical simulation.When the two kinds of fences have a porosity of 30% and a spacing of 20H(H is the height of the fence),the protection effect is optimal.Among them,the screened HDPE board has good heat resistance and cold resistance,strong UV resistance,good chemical stability and aging resistance.It was applied to the railway sand control project in high altitude desertification area for the first time,and realized the innovation of sand control materials.(5)Evaluation of the protection effectiveness of the existing protection system in the Gobi area west of Mangya Lake and in the fluid dune area of Zhonzaohuo.In the Gobi area west of Mangya Lake,the wind-proof efficiency of the front-end sand-blocking belt is 20.6%~86.5%,the sand-blocking efficiency is 24.8%~56.1%;the HDPE board square wind-proof efficiency(0.2 m height)is about 70%,The wind protection efficiency(0.5 m height)is between 40% and 50%,and the sand blocking efficiency is up to 60%.The mobile sand dune area of Zhonzaohuo,the wind-proof efficiency of the front-sand sand-blocking zone is 25.7~92.4%,and the sand-blocking efficiency is 33.1%~65.4%.(6)Based on the results of field observation,wind tunnel test and numerical simulation,according to the characteristics of wind and sand environment in Qinghai section of Golmud-Korla Railway,a comprehensive sand control system suitable for the area is constructed,mainly consisting of frontal sand blocking belt and large grid sand fixing belt.The wind-proof efficiency of the sand barrier zone at the front of the system is 90%,which is the main settlement zone of sand.The area below the height of the large-grid sand-fixing zone is almost a static wind zone.The sandstorm disaster protection system in the Gobi area west of Mangya Lake,in the basin desertification area of Mangya Lake and in the fluid dune area of Zhonzaohuo has good sand protection benefits,and is suitable for the prevention and control of sandstorm disasters in the Qinghai section of the Golmud-Korla Railway. |
PDF Full Text Request