新型预应力路堤侧压力板设计间距研究  

Study on design spacing of lateral pressure plate of a new prestressed embankment

作　　者：冷伍明[1,2] 董俊利 艾希 徐方[1,2] 张期树[1] LENG Wuming;DONG Junli;AI Xi;XU Fang;ZHANG Qishu(School of Civil Engineering,Central South University,Changsha 410075,China;National Engineering Laboratory for High Speed Railway Construction,Central South University,Changsha 410075,China;China Railway Siyuan Survey and Design Group Co.Ltd.,Wuhan 430063,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]中南大学高速铁路建造技术国家工程实验室,湖南长沙410075 [3]中铁第四勘察设计院集团有限公司,湖北武汉430063

出　　处：《中南大学学报（自然科学版）》2023年第4期1379-1392,共14页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51978672);中南大学研究生自主探索创新项目(2021zzts0230);中南大学深化创新创业教育改革研究项目(2020CG039)。

摘　　要：基于Boussinesq和Cerruti公式推导的水平附加应力计算公式,提出新型预应力路堤加固薄弱点O处的附加应力分析方法。通过大量工况计算获得多块侧压力板联合作用下预应力路堤薄弱区域内薄弱点O处水平附加应力的扩散规律,并以该点处附加应力作为预应力加固的控制下限,探索侧压力板布置间距的设计方法。研究研究表明:1)单块侧压力板上、下板角不同外延面内的水平附加应力系数K均随水平深度系数hc的增加先增大后减小;2)加固薄弱点O处的附加应力系数KO可根据相邻4块侧压力板的附加应力扩散效应叠加求得,且在不同侧压力板间距下,KO均随hc的增加先增大后减小,即KO与hc的关系曲线均存在峰值点;3)定义侧压力板沿路堤坡向和纵向的净间距与板宽之比分别为净间距系数a和b,发现在不同路堤坡率及加固系数KP下,薄弱点O处的水平附加应力有效扩散深度系数hcp均分别随b和a的增大呈线性递减和线性递增关系,同时b和a呈指数型负相关关系;4)通过多元拟合分别建立了hcp与b(或a)以及b与a的函数关系式,可依据拟合关系设计侧压力板的布置间距。An analytical method was proposed to calculate the additional stresses at the weak reinforcement point O of a new prestressed embankment based on the calculation formulas of horizontal additional stress derived from Boussinesq and Cerruti formulas.The diffusion law of horizontal additional stress at O in the weak area of prestressed embankment under the combined action of multiple LPPs was obtained though a large number of calculations,and the design spacing of the LPPs was explored while taking the additional stress level of the weak point O as the lower control limit.The results are shown as follows.1)The horizontal additional stress coefficient(K)in the external planes beyond the upper and lower corner points of a single LPP first increases and then gradually decreases with the increase of the horizontal depth coefficient hc.2)The horizontal additional stress coefficient at the weak point O can be evaluated as the superimposition of the additional stress propagation effect of the adjacent four LPPs,and the KO with different LPP spacings first increases and then gradually decreases with the increase of hc,that is,there are peak points in KO−hc curves.3)Defining the ratios of the LPP net spacings along the slope and longitudinal directions to the LPP width as the net spacing parameters a and b,the effective propagation depth coefficient(hcp)of the horizontal additional stress at the weak point O at different embankment slope ratios and different reinforcement coefficients presents linear decline and linear increment relationships with the increaze of b and a,respectively,while b and a show an exponential negative correlation.4)The function relationships of hcp versus b(or a)and b versus a are established using multivariate fitting method,which can be used to design the LPP spacing.

关 键 词：预应力路堤 侧压力板 板间距 水平附加应力 设计方法 

分 类 号：U213[交通运输工程—道路与铁道工程]