红一线新建地方铁路联合沙障结构参数优化研究  

Structural parameter optimization of combined sand barrier of new local railway for Hongyi line

作　　者：孙婧 李家园 王海龙 刘宏波 刘畅 SUN Jing;LI Jiayuan;WANG Hailong;LIU Hongbo;LIU Chang(Hebei Key Laboratory for Diagnosis,Reconstruction and Anti-disaster of Civil Engineering,Zhangjiakou 075000,China;School of Civil Engineering,Hebei University of Architecture,Zhangjiakou 075000,China;School of Traffic and Transportation,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]河北省土木工程诊断、改造与抗灾重点实验室,河北张家口075000 [2]河北建筑工程学院土木工程学院,河北张家口075000 [3]石家庄铁道大学交通运输学院,河北石家庄050043

出　　处：《铁道科学与工程学报》2023年第1期145-155,共11页Journal of Railway Science and Engineering

基　　金：国家自然科学基金资助项目(51878242);河北省科技厅重点研发计划项目(20373802D);河北省高校基础科研业务费项目(2021XSTD02)。

摘　　要：机械沙障能控制流沙、沉降沙粒,是目前最主要的防风固沙措施。但在风沙灾害频繁发生地区,单一使用一种结构形式的沙障,大量沙粒跃移沙障后还会沿地表向前推进,风沙流控制效果不明显,必须考虑使用多种固沙措施联合的方式。依托红一线新建地方铁路工程,在现场调研基础上,设计使用钢制防风沙网板作为高立式沙障。沿风沙流前进方向,在板后一定间距处,利用当地风积沙为原料,将其固化后制备带孔固沙砖铺设成方格沙障,建立防风沙网板-固沙砖方格联合沙障。针对该联合沙障对风沙流场的影响及其阻挡风沙效果,开展了数值模拟和风洞试验研究,以优化其结构参数。研究结果表明:孔隙率对防风沙网板后不同高度处风速衰减程度影响大,结合现场沙粒起动风速,确定最佳孔隙率为30%;不同风速下,防风沙网板后有效防护距离随风速增大而减小,固沙砖方格沙障与防风沙网板合理间距范围在10H~19H(H为网板高度)。风洞试验中,板后不同高度风速分布与数值模拟结果相吻合,积沙主要出现在防风沙网板周围、防风沙网板与固沙砖沙障之间和固沙砖方格内部;当固沙砖沙障设置为5排、与防风沙网板的间距布设为18H时,固沙砖方格内沙粒沉积率最大、阻沙效果最好。固沙砖方格沙障与铁路路堤预留5 m间距,方便定期清理积沙。Mechanical sand barrier can control quicksand and settle sand particles, which is the most important wind prevention and sand fixation measure at present. However, in areas where wind sand disasters occur frequently, if only a single structural form of sand barrier is used, a large number of sand particles will move forward along the surface after jumping the sand barrier, and the control effect of wind sand flow is not obvious.The combination of multiple sand fixation measures must be considered. Relying on the new local railway project on the Hongyi line, based on the field investigation, the steel windproof sand screen plate was designed to be used as a high vertical sand barrier. Along the direction of wind sand flow, at a certain distance behind the plate, the local aeolian sand was used as the raw material. The perforated sand fixing brick was prepared after curing to form a grid sand barrier, so as to establish a windproof sand screen plate sand fixing brick grid combined sand barrier. Aiming at the influence of the combined sand barrier on the wind sand flow field and its blocking effect,numerical simulation and wind tunnel test were carried out to optimize the structural parameters of it. The results show that the porosity has the great influences on the attenuation degree of wind speed at different heights behind the windbreak sand screen. Combined with the starting wind speed of sand particles in the field, the optimal porosity is determined to be 30%. Under different wind speeds, the effective protection distance behind the windproof sand screen plate decreases with the increase of wind speed. The reasonable distance between the sand fixing brick grid sand barrier and the windproof sand screen plate is 10H~19H(H is the height of the screen plate). According to the wind tunnel tests, the wind speed distribution at different heights behind the plate is consistent with the numerical simulation results. The sand deposition mainly occurs around the windbreak sand screen plate, between the windbreak sand sc

关 键 词：钢制防风沙网板 固沙砖方格 联合机械沙障 风洞试验 铺设间距 

分 类 号：TU431[建筑科学—岩土工程]