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我国客运专线列车设计时速将达到350km,路基轨道两侧声屏障受到的脉动力也随之增大,传统插板式声屏障采用螺栓连接的钢立柱易出现螺栓松动和钢材锈蚀等现象,为此,采用预应力混凝土立柱(PC)替代钢柱则不仅能有效解决这些问题,而且,PC柱比普通混凝土柱的抗裂、抗疲劳性更优越。此外,考虑声屏障施工工效,提出了预制PC立柱的两种快速装配连接形式,即插入式后浇连接和螺栓连接。通过4个立柱试件的模拟正负列车风压及台风风压的双向推覆荷载试验,表明了插入式连接PC立柱的插入深度达到1.5倍截面高度时,在台风的设计荷载作用下,立柱不会开裂,立柱顶部侧向位移小于L/250,结构近似保持弹性工作状态;螺栓连接PC立柱满足非台风地区时速350km客运专线路基声屏障的设计要求。
China’s passenger dedicated train design speed will reach 350km, both sides of the subgrade track acoustic barrier by the pulsating force also increases, the traditional plug-in sound barrier using bolt-connected steel column prone to bolt loosening and steel corrosion and other phenomena, therefore, the use of Prestressed concrete columns (PC) instead of steel columns not only can effectively solve these problems, but also, PC column cracking better than ordinary concrete columns, fatigue resistance is superior. In addition, considering the construction efficiency of sound barrier, two rapid assembly and connection forms of prefabricated PC post are proposed, that is, plug-in pouring and bolting. Through four column specimens simulating positive and negative train wind pressure and typhoon wind pressure two-way pushover load test, it shows that when the insertion depth of the plug-in PC pillar reaches 1.5 times the cross-section height, under the design load of the typhoon, Which will not crack. The lateral displacement of the top of column is less than L / 250, and the structure is approximately elastic. The bolting of PC column meets the design requirements of subgrade sound barrier of 350 km / h passenger dedicated line in non-typhoon areas.