论文部分内容阅读
一座桥梁可以用不同的压缩程度跨越某一河流,得出不同的冲刷系数。根据河流特点和技术经济条件,最大可以压缩到什么程度,即为允许冲刷系数。或称为冲刷系数标准。 (一) 制订允许冲刷系数的依据 冲刷系数标准应该以工程费和运营费总和为最小的原则为依据。但要直接计算各种冲刷系数(各种压缩程度)对应的运营养护费有一定的困难。因此在制订冲刷系数标准时,可以用保证运营正常的最小工程费原则代替工程费和运营费总和为最小的原则。 1.技术经济计算。根据每一桥渡在可能范围内的各种冲刷系数,算出其造价R,点绘R～P关系曲线,曲线的最低点(造价R最小),即为最有利的冲刷系数P_(ono)图1是P_(on)随单宽流量q的变化。 2.不同压缩时桥渡的运营条件。毕加收集了八十多条河流上桥渡的资料,算出这些
A bridge can span a river at different degrees of compression, yielding different erosion coefficients. According to the characteristics of rivers and technical and economic conditions, the maximum can be compressed to what extent, is to allow the erosion coefficient. Or as the erosion coefficient standard. (A) to develop a basis for allowing erosion coefficient The erosion coefficient standard should be based on the principle of engineering and operating expenses for the sum of the minimum. However, it is difficult to directly calculate the operating maintenance fees corresponding to various erosion coefficients (various degrees of compression). Therefore, when formulating the erosion coefficient standard, the principle of minimum construction cost that ensures normal operation can be substituted for the principle of minimizing the sum of construction costs and operating expenses. 1. Technical and Economic Calculation According to each bridge across the range of possible erosion coefficient, calculate the cost R, point draw R ~ P curve, the lowest point of the curve (cost R minimum), is the most favorable erosion coefficient P ono chart 1 is P_ (on) with the single-wide flow q changes. 2 different compression bridge crossing operating conditions. Pica collected more than eighty rivers on the bridge of the data, calculate these