城际铁路水泥改良黄土填料力学特性

硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (7): 2409-2417.

城际铁路水泥改良黄土填料力学特性

蒋应军¹, 张伟¹, 李启龙¹, 乔怀玉²

1.长安大学,特殊地区公路工程教育部重点实验室,西安 710064;
2.陕西省铁路集团有限公司,西安 710199

收稿日期:2021-02-12 修回日期:2021-04-04 出版日期:2021-07-15 发布日期:2021-08-04
通讯作者: 张伟,硕士研究生。E-mail:zwei@chd.edu.cn
作者简介:蒋应军(1975—),男,教授。主要从事路基工程方面的研究。E-mail:2022215688@qq.com
基金资助:
陕西省交通运输厅科研项目(18-02K)

Mechanical Properties of Cement-Improved Loess Fillerfor Intercity Railway

JIANG Yingjun¹, ZHANG Wei¹, LI Qilong¹, QIAO Huaiyu²

1. Key Laboratory for Special Area Highway Engineering of Ministry of Education, Chang’an University, Xi’an 710064, China;
2. Shaanxi Province Railway Group Co., Ltd, Xi’an 710199, China

Received:2021-02-12 Revised:2021-04-04 Online:2021-07-15 Published:2021-08-04

摘要/Abstract

摘要： 为揭示城际铁路水泥改良黄土路基填料力学特性变化规律,通过室内试验研究了水泥剂量、压实系数、养护龄期对水泥改良黄土路基填料力学特性的影响规律,优化设计改良黄土填料水泥剂量。研究表明,压实系数0.92下2%(质量分数,下同)水泥剂量改良黄土试件的7 d抗压强度满足规范值,但浸水后试件破损;水泥剂量≥3%的改良黄土试件浸水后完整,水泥剂量增加1%,28 d抗压强度和劈裂强度至少分别平均增长12.3%、17.0%;压实系数提高0.01,改良黄土28 d抗压强度和劈裂强度分别至少增长了5.4%、8.0%;改良黄土前期力学强度增长速率明显大于后期强度增长速率,水泥剂量≥3%的改良黄土试件的7 d抗压强度和劈裂强度分别约是其对应极限强度的61%、45%。为保证路基强度和承载力,考虑经济效益,建议基床底层以下路堤水泥剂量为3%,压实系数为0.95;建议基床底层路堤水泥剂量为4%,压实系数为0.98。

关键词: 铁路工程, 水泥改良黄土, 路基填料, 力学特性, 工程应用

Abstract: In order to reveal the change law of the mechanical properties of the cement-improved loess subgrade fillers on the intercity railway, the influence of cement dosage, compaction coefficient, and curing age on the mechanical properties of the cement-improved loess subgrade fillers were studied through laboratory tests, and the dosage of the improved loess filler cement was optimized. The research shows that the compression strength of 2% (mass fraction, the same below) cement dosage improved loess test piece at 7 d under the compaction coefficient of 0.92 meets the standard value, but the test piece is damaged after soaking; the improved loess sample with cement dosage ≥3% is complete after soaking, and the cement dosage increases by 1%. 28 d compressive strength and splitting strength increase at least 12.3% and 17.0% on average, respectively. The compaction coefficient increases by 0.01, the compressive strength and splitting strength of the improved loess increase by at least 5.4% and 8.0%. The strength growth rate is significantly higher than that of the later stage. The compressive strength and splitting strength of the improved loess specimen with cement dosage ≥3% were about 61% and 45% of their corresponding ultimate strengths, respectively. In order to ensure the strength and bearing capacity of the subgrade, the cement dosage of the embankment below the foundation bed is recommended to be 3% and the compaction coefficient is 0.95. The cement dosage of the embankment to the bottom of the foundation bed is recommended to be 4% and the compaction coefficient is 0.98.

Key words: railway engineering, cement-improved loess, subgrade filler, mechanical property, engineering application

中图分类号:

TU411

蒋应军, 张伟, 李启龙, 乔怀玉. 城际铁路水泥改良黄土填料力学特性[J]. 硅酸盐通报, 2021, 40(7): 2409-2417.

JIANG Yingjun, ZHANG Wei, LI Qilong, QIAO Huaiyu. Mechanical Properties of Cement-Improved Loess Fillerfor Intercity Railway[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2021, 40(7): 2409-2417.

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