不同垫层下煤矸石桩网复合路基承载特性
Bearing characteristics of coal gangue pile-net composite embankment with different cushion layers
邓友生 1姚志刚 1冯爱林 1李龙 1孟丽青 1肇慧玲1
作者信息
- 1. 西安科技大学桩承结构研究中心,陕西西安 710054;西安科技大学建筑与土木工程学院,陕西西安 710054
- 折叠
摘要
为综合利用固体废弃物煤矸石,将其取代部分传统细骨料制备煤矸石混凝土桩.开展了土工格栅和土工格室加筋垫层下煤矸石桩网复合路基室内模型试验,分析路堤顶面荷载-沉降关系、加筋垫层传荷能力和桩身应力的差异性.同时,建立有限元计算模型,研究不同加筋材料应力和变形规律,揭示土工格室应用于加筋垫层作用机制.结果表明:在本次试验中,同土工格栅相比,土工格室加筋垫层显著减小路堤顶面沉降约29.71％.土工格室加筋垫层下桩顶和桩间处土压力衰减量分别约61.51％、56.35％,充分发挥了筏板效应和应力扩散效应.采用土工格室加筋垫层,路堤荷载能够被有效传递至煤矸石桩体,在路基中心处和沿路基横断方向桩身应力极值分别采用土工格栅加筋垫层的1.78、1.80倍.土工格室和土工格栅应力分布规律分别呈"V"型和"U"型变化特征,且土工格室的应力最大值大于土工格栅.土工格室特有的蜂窝状结构对路堤填料产生侧向环箍和肋条摩阻力作用,通过自身张拉变形有效地扩散路堤荷载.
Abstract
In order to comprehensively utilize solid waste coal gangue,coal gangue concrete piles were prepared by replacing part of traditional fine aggregate.Laboratory model tests of coal gangue pile-net composite embankments under reinforced cushions of geocells and geogrids were conducted to analyze the differences in load-settlement relationships of the embankment top surface,load transfer capabilities of the reinforced cushions,and stress distributions within the piles.Additionally,a finite element calculation model was established to investigate the stress and deformation patterns of different reinforcing materials,revealing the mechanism of geocells applied in reinforced cushions.The results indicate that,in this test,compared to geogrids,the geocell reinforced cushion significantly reduced the settlement of the embankment top by approximately 29.71％.Under the geocell reinforced cushion,the attenuation of soil pressure at the top of the piles and between piles was approximately 61.51％and 56.35％,respectively,fully utilizing the raft effect and stress diffusion effect.When using a geocell reinforced bedding,the embankment load was more effectively transferred to the coal gangue piles,with the extreme values of pile stress at the center of the roadbed and along the cross-section of the roadbed being 1.78 and 1.80 times greater,respectively,than those using geogrid reinforced bedding.The stress distributions of geocells and geogrids exhibited"V"-shaped and"U"-shaped patterns,respectively,and the maximum stress value of geocells was greater than that of geogrids.The unique honeycomb structure of the geocell exerts lateral hoop and rib friction resistance on the embankment fill,effectively diffusing the embankment load through its own tension and deformation.
关键词
桩网复合路基/煤矸石桩/土工格室/加筋垫层荷载传递/桩身应力Key words
pile-net composite embankment/coal gangue pile/geocell/load transfer of reinforced cushion/pile stress引用本文复制引用
基金项目
国家自然科学基金项目(51878554)
国家自然科学基金项目(41672308)
陕西省自然科学基础研究计划重点项目(2018JZ5012)
出版年
2024
国家科技期刊平台
NSTL
万方数据