荷载作用下拱形玻璃钢夹砂结构受力特征分析

ANALYSIS OF MECHANICAL CHARACTERISTICS OF ARCHED FRP SAND-SAND STRUCTURE UNDER LOAD

为研究埋地拱形玻璃钢夹砂结构作为装配式涵洞顶部的受力与变形特性,将拱形玻璃钢夹砂结构嵌入两侧混凝土直墙中,以结构最大允许变形量为控制指标,设计埋地玻璃钢夹砂拱形结构的模拟荷载试验,研究半圆、半椭圆、荷载值、覆土高度等因素构成的6种工况下拱形结构的力学参数,验证玻璃钢夹砂结构作为涵洞顶部结构的可行性。研究结果表明:在相同变形的情况下,覆土高度为30cm时半椭圆拱形结构承受荷载比半圆形高出10.7%,覆土高度为60cm时提高10.5%,当覆土高度为90cm时,试验加载至52t,由于土体发生剪切破坏而使试验提前终止,但玻璃钢材料均未出现裂缝等破坏形式;随着矢跨比的减小,水平推力逐渐变大,在相同荷载作用下,半圆形玻璃钢夹砂结构在不同覆土高度时水平和竖向位移分别比半椭圆形的要高出23%、16%以上;半椭圆结构受力更好,两种拱形玻璃钢夹砂结构均可作为装配式涵洞顶部结构,可为今后玻璃钢材料的推广与应用提供理论支撑。

In order to study the stress and deformation characteristics of the buried arched FRP sand-filled structure as the top of the assembled culvert, the arched FRP sand-filled structure is embedded in the concrete straight wall on both sides, and the maximum allowable deformation of the structure is taken as the control index. The simulated load test of the buried glass fiber reinforced plastic arched structure is carried out. The mechanical parameters of the arched structure under six working conditions, such as semicircle, semi-ellipse, load value and soil height, are studied. The feasibility of the glass-reinforced sand-sand structure as the top structure of the culvert is verified. The results show that in the case of the same deformation, the semi-elliptical arch structure with a cover height of 30 cm is 10.7% higher than the semicircle, 10.5% when the cover height is 60 cm, and 90 cm when the cover height is loaded to 52 tons. The shear failure of the body caused the test to terminate prematurely, and the FRP material did not show cracks and other damages;as the span ratio decreased, the horizontal thrust became larger. Under the same load, the semi-circular FRP sand-sand structure was covered in different soils. The horizontal and vertical displacements are 23%~33% and 16%~22% larger than the semi-ellipse, respectively. Therefore, the semi-elliptical structure is better stressed. Both arched FRP sand structures can be used as the assembled culvert top structure. This provides theoretical and technical support for the promotion and practical construction of FRP materials in the future.