铁路企业营改增对招投标工作的影响及对策

结合铁路系统实行营改增的实际情况,介绍了增值税的主要特点,分析了铁路企业营改增的盈亏平衡点,提出了营改增后招标工作的对策。     

A simplified analysis method for the lateral deformation of braced excavations

Pile-anchor retaining structure is widely used in foundation pit engineering and side slope engineering in many countries. In contrast to strut, pile-anchor retaining structure has its typical features and advantages. It does not occupy the internal space of the foundation pit, and the project cost is much lower. Accurate prediction of the lateral displacement of the retaining structure is very important in the design stage. A simplified analysis method and several calculation assumptions of the lateral deformation of pile-anchor retaining structures are set up according to the engineering features. The expression function of lateral displacement versus depth is solved by means of a fitted function and the quasi-elastic summation method. The parameters are obtained through the stiffness equation of the anchors and the principle of minimum potential energy. The analytical evaluation of the lateral deformation curve is then completed, whose applicability is proved through practical engineering.     

城市地下快速道路空气净化技术的发展战略研究

城市地下道路中由机动车排放的污染气体,无论是通过高风塔排放,还是经由隧道洞口通风排出,都会对周边环境空气质量造成负面影响。随着国内相关规范的出台和国民对大气环境关注度日益提升,对城市地下道路中的空气污染物进行净化处理已经成为了大势所趋。在综述国外隧道污染空气净化技术发展历史和应用现状的基础上,分析了我国新建地下快速道路引进空气净化技术的发展战略。     

引江济淮工程安徽段生态岸坡防护结构形式综述*

运河工程沿线渠道开挖将产生大面积的人工创面，采用生态岸坡防护工程对创面修复有积极作用。以引江济淮工程安徽段岸坡防护工程为研究对象，基于设计资料和现场调研梳理了引江济淮工程安徽段生态岸坡防护结构使用情况。结果表明：引江济淮工程生态结构选型主要受地质条件及特征水位影响，土质岸坡常水位以上采用30%孔隙率的混凝土预制块体结构，枯水位局部河段试验性采用带有鱼巢功能的水下矩阵块体结构。膨胀土区域采用大框格预制块体结构及柔性水位保持毯材料，孔隙率分别为79%和95%，使用区域均位于最高洪水位以上。