工程地质学报
工程地質學報
공정지질학보
2014年
6期
1294-1300
,共7页
庄海洋%陈磊%沈礼伟%左玉峰
莊海洋%陳磊%瀋禮偉%左玉峰
장해양%진뢰%침례위%좌옥봉
列车振动荷载%南京细砂%累积变形%振动孔压%土动力学
列車振動荷載%南京細砂%纍積變形%振動孔壓%土動力學
열차진동하재%남경세사%루적변형%진동공압%토동역학
Train-induced vibration%Nanjing fine sand%Accumulated deformation%Dynamic pore pressure%Soil dynamic
列车振动荷载作用下松散砂土振密造成的早期路基沉降将对列车的正常运行产生很大的影响。本文以南京地区新近沉积片状细砂为研究对象，采用英国GDS空心圆柱扭剪仪模拟列车振动荷载的实际应力路径，并考虑排水条件、试样围压和加载幅值等因素，初步研究了2000列次（14000振次）列车振动荷载作用下南京新近沉积片状细砂的振动排水特性和竖向累积变形特性。实验结果表明，试样围压对南京片状细砂的竖向累积变形的影响较为明显，同时，当试验围压较小时，加载幅值对试样的竖向累积变形的影响更大。其次，排水条件主要对列车运营前期的路基累积变形产生明显的影响，对后期的累积变形的影响基本可以忽略。最后，根据试验结果，本文也初步给出了排水条件和不排水条件下南京片状细砂的竖向累积应变增长曲线的新预测公式及其参数取值。研究结论对列车振动荷载作用下新近沉积砂性土的动力学特性及其累积变形的计算方法等问题的研究具有很好的参考价值。
列車振動荷載作用下鬆散砂土振密造成的早期路基沉降將對列車的正常運行產生很大的影響。本文以南京地區新近沉積片狀細砂為研究對象，採用英國GDS空心圓柱扭剪儀模擬列車振動荷載的實際應力路徑，併攷慮排水條件、試樣圍壓和加載幅值等因素，初步研究瞭2000列次（14000振次）列車振動荷載作用下南京新近沉積片狀細砂的振動排水特性和豎嚮纍積變形特性。實驗結果錶明，試樣圍壓對南京片狀細砂的豎嚮纍積變形的影響較為明顯，同時，噹試驗圍壓較小時，加載幅值對試樣的豎嚮纍積變形的影響更大。其次，排水條件主要對列車運營前期的路基纍積變形產生明顯的影響，對後期的纍積變形的影響基本可以忽略。最後，根據試驗結果，本文也初步給齣瞭排水條件和不排水條件下南京片狀細砂的豎嚮纍積應變增長麯線的新預測公式及其參數取值。研究結論對列車振動荷載作用下新近沉積砂性土的動力學特性及其纍積變形的計算方法等問題的研究具有很好的參攷價值。
열차진동하재작용하송산사토진밀조성적조기로기침강장대열차적정상운행산생흔대적영향。본문이남경지구신근침적편상세사위연구대상，채용영국GDS공심원주뉴전의모의열차진동하재적실제응력로경，병고필배수조건、시양위압화가재폭치등인소，초보연구료2000렬차（14000진차）열차진동하재작용하남경신근침적편상세사적진동배수특성화수향루적변형특성。실험결과표명，시양위압대남경편상세사적수향루적변형적영향교위명현，동시，당시험위압교소시，가재폭치대시양적수향루적변형적영향경대。기차，배수조건주요대열차운영전기적로기루적변형산생명현적영향，대후기적루적변형적영향기본가이홀략。최후，근거시험결과，본문야초보급출료배수조건화불배수조건하남경편상세사적수향루적응변증장곡선적신예측공식급기삼수취치。연구결론대열차진동하재작용하신근침적사성토적동역학특성급기루적변형적계산방법등문제적연구구유흔호적삼고개치。
The earlier settlement of railway roadbed caused by train-induced vibration loading has great effects on the train driving safety if loose sand layers are included in the railway foundation.Accordingly,the GDS triaxial hollow cylindrical multi-function apparatus is used to model the real stress path of the train-induced vibration loading.The tested fine sand is distributed in Nanjing area,near to Yangtze rive.Its dynamic deformation properties are studied by taking into consideration of the drain condition and the confining pressure and the load amplitude.As results,the confining pressure has a greater effect on the vertical accumulated deformation of the test samples.The amplitude of vibration loading has a greater effect on the vertical accumulated deformation if the confining pressure is smaller.Also,the drain condition has a greater effect on the earlier settlement of roadbed than on the later settlement.At the same time,the new formulas and its parameters are developed and can be used to predict the vertical accumulated deformation of Nanjing fine sand with flake-shape structure.They are given based on the test results.These research conclusions can be used to predict the long-term settlement of railway roadbed with the newly deposited fine sand included in roadbed.
