新型钢弹簧浮置板道床隔振试验与数值分析研究

提出了一种附加位移放大杠杆的新型钢弹簧浮置板道床隔振装置并进行了理论分析,给出了该装置基于位移放大倍数的阻尼力和耗能计算公式。同时设计制作了附加3倍位移放大的新型钢弹簧浮置板道床隔振装置并进行了地铁振动测试,试验结果表明:该装置隔振效果显著。通过建立新型钢弹簧浮置板道床隔振系统有限元分析模型,数值模拟结果与实测振动数据可进行较好的吻合,结果表明:新型钢弹簧浮置板道床隔振系统能有效地减小结构的动力响应。     

哈尔滨市地铁1号线某站应急监测及数据分析

地铁在运行过程中,隧道难免出现沉降,为了确保地铁安全运行,本文对哈尔滨市地铁1号线某站进行了应急监测及数据详细分析,监测数据表明,在观测期间,轨道各监测点沉降平均值相对车站结构呈下降趋势,监测的轨道沉降相对稳定。     

钢弹簧浮置板道床在西安地铁中减振效果分析

西安地铁二号线绕行通过西安钟楼,为降低地铁长期运营对钟楼的振动影响,在钟楼段采用钢弹簧浮置板道床进行减振。主要以地铁二号线运行影响下对钟楼的振动监测数据为基础,通过对钢弹簧浮置板道床段和普通道床段的振动实测值比较与分析,得出隧道内减振段和普通段的振动差异,以此评价钢弹簧浮置板道床在地铁应用中的减振效果。     

Flow resistance of gravel bed channels

Existing resistance formulas produce a wide range of friction-factor estimates for gravel bed streams. The purpose of this paper is to develop a reliable resistance formula in terms of the Darcy-Weisbach friction factor f Published data were screened and used to establish the formula. The existing formulas have considered thatfis a function of relative roughness D84/R only, where R is the hydraulic radius and 1984 is the particle size referred to the intermediate diameter that equals or exceeds that of 84 percent of bed sediments. In this paper, f is considered as a ftmction of Froude number in addition to the relative roughness, ffor D84/R〉l displays a different trend than that for Dsn/R〈l perhaps due to the invalid assumption of a logarithmic velocity distribution for D84/R〉l. Anfformula for Dsa/R〈l has been established.