摘要：The modern transportation system is increasingly developed during recent *** is an effective solution to set the noise barriers to reduce the traffic noise pollution caused by different kinds of transportation *** deficiencies on concrete noise barriers and metal noise barriers with rivet structure can be eliminated by a new kind of noise barrier with no-riveted *** mechanical performance examination and acoustic performance test are conducted on the new-designed noise barrier with no-riveted *** results indicate that the maximum stress is 1.74 MPa and the maximum deformation is 1.04 mm with load acting on the unit *** noise reduction coefficient of this kind of no-riveted noise barrier unit plate is 0.75 and its noise insulation is 40 dB,which were conform to or superior to the standard ***,this new designed noise barrier meets the field application requirements of mechanical and acoustic performance,which demonstrates the noise barriers can be widely promoted.

摘要：轻质高强是混凝土声屏障发展的趋势,其壳体材料选择和结构设计是关键。为解决台风区高速铁路混凝土声屏障容易开裂、变形过大等问题,壳体材料采用钢纤维高性能混凝土。通过理论计算、结构试验并考虑施工因素,制作内空腔无隔板,壳体最小壁厚25 mm的新型声屏障单元板。试验研究表明,背板在8.0 k Pa极限弯矩作用下,单元板没有开裂破损,跨中挠度较小,与有限元分析结果比较吻合。而且单元板自重小,制作方法简单,运输方便,具有良好的抗弯性能,满足台风地区高铁混凝土声屏障的要求。

摘要：采用发泡法,在陶粒制作工艺中添加碳酸氢铵发泡剂,增加热处理程序。通过宏观试验和微观表征,控制发泡剂用量、升温速率、养护时间来调节陶粒的孔径、显孔率以及孔的有序性等微观结构,实现陶粒孔结构的可控,从而优化陶粒的吸声性能。研究表明:发泡剂的添加量越多、升温速率越高、增加热处理程序之前养护时间越短,所制备的陶粒显孔率越大、孔径越细小、孔排列的结构越有序均匀。当发泡剂的添加量为2.0 wt%、升温速率为20℃/min、热处理之前零养护时,可制备出最高显孔隙率为32.67%,平均孔径为0.31μm,孔结构有序均匀排列的多孔陶粒,并有效改善多孔材料在低频范围吸声性能;整个控制机理下所制备的多孔陶粒筒压强度都大于2.0 MPa,满足规范和使用要求。

摘要：为寻找对“U”型管改造的理论依据 ,编制了FORTRAN计算程序 ,计算出不同条件下的水出口温度、气体出口温度和壁温 ,并据此对“U”型管进行环隙改大等项改造。