AXLE LOAD SHIFTS DURING TRUCK BRAKING AND THEIR IMPLICATIONS FOR BRIDGE AND PAVEMENT DESIGN
AXLE LOAD SHIFTS DURING TRUCK BRAKING AND THEIR IMPLICATIONS FOR BRIDGE AND PAVEMENT DESIGN
复制标题
DOI：
10.1139/l89-026
复制
发表时间：
1989-04
影响因子：
1.4
通讯作者：
B. Hutchinson;L. Rilett;R. Green;R. Haas
中科院分区：
文献类型：
--
作者：
B. Hutchinson;L. Rilett;R. Green;R. Haas
四种类型的卡车在制动过程中的轴载转移估计使用理论制动模型和这些轴载转移的桥梁和路面设计的影响进行了探讨。检查的卡车类型是三轴直卡车，五轴牵引半挂车，七轴牵引半挂车与两个空气提升腹轴，和七轴B列车牵引双拖车，每一个装载到法律的安大略限制与称重商品。每种类型的卡车在制动时都经历了大量的载荷转移到前转向轴，主要来自后纵列轴组，其中前轴载荷增加从38%到48%不等。根据安大略桥梁公式以及与参考设计卡车引起的力矩相比，在单跨桥梁中引起的力矩，检查了荷载转移对桥梁设计的影响。对于所使用的制动模型，减速和相关的轴载变化不会导致桥梁设计和评估的更高力。路面损坏的影响进行了分析，在1986年在加拿大各地的一些路面站点进行的一些负载测试中得出的负载等效函数。这些当量增加了50%的静态值为三轴卡车在最大制动。有人建议，主要损害的影响是在城市地区的交叉口，增加结构部分可以设计来处理增加的当量。
The axle load shifts of four truck types during braking are estimated using theoretical braking models and the implications of these axle load shifts for bridge and pavement design are explored. The truck types examined are a three-axle straight truck, a five-axle tractor semi-traler, a seven-axle tractor semi-trailer with two air-lift belly axles, and a seven-axle B-train tractor-double trailer, each loaded to legal Ontario limits with weigh-out commodities. Each of the truck types experienced a substantial load transfer to the front steering axles under braking, mainly from the rear tandem axle groups, where the front axle load increase varied fron 38 to 48%. The bridge design implications of the load shifts are examined in terms of the Ontario Bridge Formula and the moments induced in simple-span bridges compared with the moments induced by a reference design truck. For the braking model used, the decelerations and associated shifts in axle load do not lead to higher forces for bridge design and evaluation. The pavement damage implications are analyzed in terms of load equivalency functions derived from some load tests conducted at a number of pavement sites across Canada in 1986. These equivalencies increased up to 50% of the static values for the three-axle truck at maximum braking. It is suggested that the major damage implications are at intersections in urban areas and that increased structural sections could be designed to handle the increased equivalencies.