岩土力学2024,Vol.45Issue(9) :2565-2572,2582.DOI:10.16285/j.rsm.2023.1572

考虑级配影响的粗粒土-格栅最优网格尺寸试验研究

Experimental study on optimal grid size of coarse-grained soil-grid considering the effect of gradation

蒋明杰 李泽懿 吉恩跃 刘宇菠 梅国雄
岩土力学2024,Vol.45Issue(9) :2565-2572,2582.DOI:10.16285/j.rsm.2023.1572

考虑级配影响的粗粒土-格栅最优网格尺寸试验研究

Experimental study on optimal grid size of coarse-grained soil-grid considering the effect of gradation

蒋明杰 1李泽懿 1吉恩跃 2刘宇菠 1梅国雄3
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作者信息

  • 1. 广西大学工程防灾与结构安全教育部重点实验室,广西南宁 530004;广西大学广西防灾减灾与工程安全重点实验室,广西南宁 530004
  • 2. 南京水利科学研究院岩土工程研究所,江苏南京 210024
  • 3. 浙江大学海洋学院,浙江舟山 316021
  • 折叠

摘要

土工格栅作为土石坝常用的加筋材料,根据颗粒级配采用适合的格栅网格尺寸可显著提高土石坝抗震性能,探究级配影响下最优网格尺寸变化规律具有工程意义.基于连续级配的级配方程,通过改变最大粒径dmax和级配面积S,设计15组级配土料,采用4组不同网格尺寸La对各个土料加筋,做成60组加筋试样.利用大型直剪仪对各个试样进行循环剪切试验,从而定量研究级配与能使加筋粗粒土抗震性能达到最优的土工格栅网格尺寸之间的关系.试验发现,当dmax及La一定时,级配面积存在一个最优值使抗震性能达到最佳,将此定义为最优级配面积Sopt;当网格尺寸一定时,Sopt随dmax增大而增大,两者之间呈明显的对数关系;当dmax一定时,Sopt随La增大而减小,两者之间也呈明显的对数关系.建立定量描述dmax和La对最优级配面积Sopt的耦合影响的计算模型,并结合工程实际,提出基于室内试验结果预测现场粗粒土原级配对应最优网格尺寸的经验公式.

Abstract

Geogrid,commonly used for reinforcement in rockfill dams,significantly enhances seismic performance when appropriate grid dimensions are selected based on particle size distribution.Investigating the variations in optimal grid dimensions influenced by particle size distribution is of great engineering importance.By employing the continuous grading equation,15 sets of graded soils were developed by varying the maximum particle size dmax and grading area S.Creating 60 reinforced specimens by using four different grid sizes La to reinforce each soil.Subsequently,large-scale direct shear tests were performed on each specimen to quantitatively analyze the correlation between grading area and geogrid dimensions,aiming to optimize the seismic performance of reinforced coarse-grained soil.The experimental results show that there is an optimal grading area,Sopt,that maximizes seismic performance when dmax and La are fixed.When the grid size remains constant Sopt increases logarithmically as dmax increases.Conversely,when dmaxis constant,Sopt decreases logarithmically as La increases.A quantitative model is developed to dmax describe the combined effects of dmax and La on Sopt.This model is integrated with engineering practices to propose an empirical formula based on indoor test results for predicting the optimal grid dimensions for the original grading of coarse-grained soil on-site.

关键词

粗粒土/土工格栅/颗粒级配/循环剪切/最优网格尺寸

Key words

coarse-grained soil/geogrid/particle grading/cyclic shear/optimum mesh size

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基金项目

国家自然科学基金(52108309)

国家自然科学基金(52178321)

广西科技计划项目(2021 AC 18008)

广西自然科学基金(2021GXNSFBA196091)

出版年

2024
岩土力学
中国科学院武汉岩土力学研究所

岩土力学

CSTPCDCSCD北大核心
影响因子:1.614
ISSN:1000-7598
参考文献量24
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