The Lanzhou-Xinjiang high-speed railway(HSR)traverses areas of the Gobi Desert where extremely strong winds are frequent.These strong winds cause sand/gravel hazards,an unaddressed issue that often seriously compromis...The Lanzhou-Xinjiang high-speed railway(HSR)traverses areas of the Gobi Desert where extremely strong winds are frequent.These strong winds cause sand/gravel hazards,an unaddressed issue that often seriously compromises the safe operation of the HSR.This paper studies the mechanisms leading to wind-blown sand hazards and the outcomes of sand control projects in these areas.The main findings are as follows:(1)Cold northern airflows over the Tian Shan mountain range are accelerated by the wind tunnels and downslope effect as they pass over complex terrain comprising passes,gullies,and proluvial fans.Consequently,the wind intensity often increases two-to threefold,creating frequent high-speed winds that lead to severe sand damage along the HSR.(2)In the Gobi areas with extremely strong winds,sand grains can be lifted as high as 9 m from the ground into the air,far higher than in other areas of the desert.The sand transport rate decreases exponentially with increasing height.Both wind speed and particle size determine saltation height.Coarser particles and stronger winds provide the particles with a higher kinetic energy as they collide with the ground.In the wind zones of Baili and Yandun,the analysed study areas,the saltation layer height of wind-blown sand/gravel exceeds 3 and 2 m,respectively.(3)Based on the above findings,recently emerging sand control materials,suitable for the areas of interest,were screened and developed.Furthermore,under the proposed principle of‘supplementing blocking with trapping’,a comprehensive sand control measure was established,featuring sandblocking belts comprised of multiple rows,and high,vertical sand-trapping installations with a large grids size.The installed system showed a high efficacy,reducing sand transport rate by 87.87%and significantly decreasing the deposition of sand along a trial section of the HSR.展开更多
为了得到内陆区复杂地形桥位风场特性，并提供正确的风荷载计算依据，对内陆强风和沿海台风两大强风带风特性开展研究，并从二者产生原因、特点及风参数等方面进行了比较。在对龙门黄河大桥桥位长期风观测研究中，采用多站点、多测点立...为了得到内陆区复杂地形桥位风场特性，并提供正确的风荷载计算依据，对内陆强风和沿海台风两大强风带风特性开展研究，并从二者产生原因、特点及风参数等方面进行了比较。在对龙门黄河大桥桥位长期风观测研究中，采用多站点、多测点立体观测得到了538个观测日的大风样本，经统计分析，得到了内陆强风区实测风场参数的分布和规律：内陆强风区受地形影响，风速和风向既带有明显的季风环流基本规律，又带有明显的区域特征；气流攻角在-9~8°范围内，比平原地区大，应以实测数据为主；受复杂地形效应的影响，实测得到的内陆强风区风剖面指数并不完全符合幂指数分布，《公路桥梁抗风设计规范》（JTG/ T D60-01-2004）（以下简称《规范》）所建议公式不适用；湍流度平均值在0.103~0.13之间，阵风因子平均值在1.22~1.39之间，不同于《规范》取值，随着平均风速的增大二者有减小的趋势，且存在明显的线性相关性；湍流积分尺度取值与《规范》建议的平坦地貌尺度不同，且一般偏大；风谱的拟合应该按照不同频率区分段，选用不同的风谱公式。展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.41730644,41901011&41771010)。
文摘The Lanzhou-Xinjiang high-speed railway(HSR)traverses areas of the Gobi Desert where extremely strong winds are frequent.These strong winds cause sand/gravel hazards,an unaddressed issue that often seriously compromises the safe operation of the HSR.This paper studies the mechanisms leading to wind-blown sand hazards and the outcomes of sand control projects in these areas.The main findings are as follows:(1)Cold northern airflows over the Tian Shan mountain range are accelerated by the wind tunnels and downslope effect as they pass over complex terrain comprising passes,gullies,and proluvial fans.Consequently,the wind intensity often increases two-to threefold,creating frequent high-speed winds that lead to severe sand damage along the HSR.(2)In the Gobi areas with extremely strong winds,sand grains can be lifted as high as 9 m from the ground into the air,far higher than in other areas of the desert.The sand transport rate decreases exponentially with increasing height.Both wind speed and particle size determine saltation height.Coarser particles and stronger winds provide the particles with a higher kinetic energy as they collide with the ground.In the wind zones of Baili and Yandun,the analysed study areas,the saltation layer height of wind-blown sand/gravel exceeds 3 and 2 m,respectively.(3)Based on the above findings,recently emerging sand control materials,suitable for the areas of interest,were screened and developed.Furthermore,under the proposed principle of‘supplementing blocking with trapping’,a comprehensive sand control measure was established,featuring sandblocking belts comprised of multiple rows,and high,vertical sand-trapping installations with a large grids size.The installed system showed a high efficacy,reducing sand transport rate by 87.87%and significantly decreasing the deposition of sand along a trial section of the HSR.
文摘为了得到内陆区复杂地形桥位风场特性，并提供正确的风荷载计算依据，对内陆强风和沿海台风两大强风带风特性开展研究，并从二者产生原因、特点及风参数等方面进行了比较。在对龙门黄河大桥桥位长期风观测研究中，采用多站点、多测点立体观测得到了538个观测日的大风样本，经统计分析，得到了内陆强风区实测风场参数的分布和规律：内陆强风区受地形影响，风速和风向既带有明显的季风环流基本规律，又带有明显的区域特征；气流攻角在-9~8°范围内，比平原地区大，应以实测数据为主；受复杂地形效应的影响，实测得到的内陆强风区风剖面指数并不完全符合幂指数分布，《公路桥梁抗风设计规范》（JTG/ T D60-01-2004）（以下简称《规范》）所建议公式不适用；湍流度平均值在0.103~0.13之间，阵风因子平均值在1.22~1.39之间，不同于《规范》取值，随着平均风速的增大二者有减小的趋势，且存在明显的线性相关性；湍流积分尺度取值与《规范》建议的平坦地貌尺度不同，且一般偏大；风谱的拟合应该按照不同频率区分段，选用不同的风谱公式。
