Experimental Study on Improvement of Heavy-haul Railway Subgrade Filler
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摘要: 基于静动力学试验，研究纤维改良、固化剂改良及纤维–固化剂改良三种加固方法对重载铁路路基填料性能的影响，进而提出最佳改良方案。结果表明：采用固化剂改良，固化土中固化剂掺量为5%时，强度达到峰值，养护时间越长强度越高。采用纤维改良，当纤维掺量为0.2%时，纤维土静动力学性能达到最佳；当纤维长度为0～12 mm时，强度随着纤维长度的增加而增强，当长度为12～18 mm时，强度随着纤维长度的增加而降低。采用纤维–固化剂联合改良方案加固效果最好。建议该地区采用纤维–固化剂联合改良方案增强路基填料物理力学性能，试验得出的最佳掺量为：固化剂掺量5%，纤维掺量0.2%，纤维长度12 mm。Abstract: Based on static and dynamic triaxial tests, the effects of three reinforcement methods, including fiber improvement, curing agent improvement, and fiber - curing agent improvement, on the performance of heavy-haul railway subgrade filler were studied, and the best improvement scheme was proposed. The results show that when the curing agent content in the curing soil is 5%, the strength reaches the peak, and the longer the curing time, the higher the strength. With fiber improvement, when the fiber content is 0.2%, the soil static dynamic performance of fiber reaches the best; When the fiber length is 0~12 mm, the strength increases with the increase of fiber length, and when the length is 12~18 mm, the strength decreases with the increase of fiber length. The fiber-curing agent combined improvement scheme is the best reinforcement effect. It is recommended that the fiber-curing agent combined improvement scheme be used to enhance the mechanical properties of the subgrade filler, and the optimal curing agent content is 5%, fiber content is 0.2%, and fiber length is 12 mm.
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表 1 路基填料土样颗粒级配
粒径/mm 质量含量/% 粒径/mm 质量含量/% ＞10 1.130 1～0.5 15.613 10～5 10.130 0.5～0.25 13.144 5～2 11.233 0.25～0.075 18.188 2～1 27.700 ≤0.075 2.862 
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表 2 聚丙烯纤维的物理力学性能
类型 密度$ \rho $/(g·cm−3) 直径/μm 熔点/℃ 燃点/℃ 断裂伸长率/% 弹性模量/GPa 抗拉强度/MPa 单丝Y型 0.91 31 165~170 590 30 ≥3.5 ≥350
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表 4 路基填料改良静力试验工况
编号 土的
类型含水率
w/%围压
σ3/MPa纤维
长度/mm纤维
掺量/%固化剂
掺量/%养护
时间/天X-L1 纤维土 8.5 0.3 0 0 X-L2 18 0.05 X-L3 0.1 X-L4 0.2 X-L5 0.3 X-M1 0 0 X-M2 3 0.3 X-M3 9 X-M4 12 X-M5 18 G-3 固化土 11.5 0.3 3 3 G-4 4 G-5 5 G-D1 5 3 G-D2 14 G-D3 28
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表 5 动力试验工况与拟合参数
编号 压实度 围压$ {\sigma _3} $/MPa 频率$ f $/Hz 含水量w/% WY0.5 1.00 0.5 4 8.5 WY0.9 0.9 WY1.2 1.2 f1 0.3 1 8.5 f2 2 f3 3 f5 5 w10 0.3 4 10 w12 12 w14 14 YS0.85 0.98 0.3 2 8.5 YS0.98 0.85
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[1] HIRAKAWA D, MIYATA Y. Roller compaction behavior of short fiber reinforced gravelly soil[J]. Japanese Geotechnical Society Special Publication,2016,2(64):2164-2169. doi: 10.3208/jgssp.JPN-080 [2] PATEL S K, SINGH B. Strength and deformation behavior of fiber reinforced cohesive soil under varying moisture and compaction states[J]. Geotechnical and Geological Engineering,2017,35(4):1767-1781. doi: 10.1007/s10706-017-0207-y [3] 李 建, 唐朝生, 王德银, 等. 基于单根纤维拉拔试验的波形纤维加筋土界面强度研究[J]. 岩土工程学报,2014,36(9):1696-1704. [4] 朱定华, 董磊平, 何 峰, 等. 聚苯乙烯纤维轻质混合土的抗压强度特性[J]. 南京工业大学学报,2010,32(2):53-57. [5] SANTONI R L, TINGLE J S, WEBSTER S L. Engineering properties of sand-fiber mixtures for road construction[J]. Journal of Geotechnical and Geoenvironmental Engineering,2001,127(3):258-268. doi: 10.1061/(ASCE)1090-0241(2001)127:3(258) [6] MAHMOUD G, MAHYA R. The influence of freeze-thaw cycles on the unconfined compressive strength of fiber reinforced clay[J]. Cold Region Science and Technology,2010,61(2/3):125-131. [7] MAHIPAL S C, SATYENDRA M, BIJAYANANDA M. Performance evaluation of silty sand subgrade reinforced with fly ash and fibre[J]. Geotextiles and Geomembranes,2008,26(5):429-435. doi: 10.1016/j.geotexmem.2008.02.001 [8] 唐朝生, 施 斌, 高 玮, 等. 含砂量对聚丙烯纤维加筋黏性土强度影响的研究[J]. 岩石力学与工程学报,2007,26(S1):2968-2973. [9] 雷胜友, 丁万涛. 加筋纤维抑制膨胀土膨胀性的试验[J]. 岩土工程学报,2005,27(4):482-485. [10] 张守超. 严寒地区高速铁路路基填料新型防冻胀改良技术研究[D]. 北京: 中国铁道科学研究院, 2017. [11] 王翰越, 蒋应军. 石灰改良黄土路基填料抗冻性能分析[J]. 中国科技论文, 2020, 2(15): 154-158. [12] 贺建清, 张家生. 石灰改良软土路基填料饱水强度特征性研究[J]. 矿冶工程,2004,24(4):18-21. [13] 王天亮, 刘建坤, 田亚护. 水泥及石灰改良土冻融循环后的动力特性研究[J]. 岩土工程学报,2010(11):1733-1737. [14] 刘永红. 石灰改良黄土路堤特性试验研究[D]. 成都: 西南交通大学, 2007. [15] 刘 鹭. 冻融作用下秸秆纤维加筋土力学特性研究[J]. 岩土工程技术, 2022, 36(3): 243-247. [16] 周易平. 高速铁路路基填料改良技术的研究[D]. 北京: 铁道部科学研究院, 2000. [17] 仇安兵. 废弃纤维改良水泥固化土力学特性及破坏模式研究[J]. 岩土工程技术, 2022, 36(1): 79-85. -
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