新型静止侧压力系数试验仪的研制与应用
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摘要
研制了一种新型静止侧压力系数试验仪,介绍了该仪器结构及工作原理。对干砂进行了试验,测定其静止侧压力系数,与传统的水囊式K_0固结仪试验结果进行了对比。分析了该试验仪的可能误差来源,主要包括加载过程中的试样侧向变形和试样与压力室筒壁之间的摩擦力,具体分析了试样侧向变形引起K_0值误差的大小,提出了摩擦力影响修正方法,充分论证了仪器的准确性和有效性。对某粗颗粒土进行了静止侧压力系数试验,测定了该土在加载及卸载条件下K_0随应力状态的变化,验证了仪器对粗颗粒土的适用性。该仪器结构简单,操作方便,结果准确,适用于包括粗颗粒土在内的各种土的K_0试验,克服了现有的静止侧压力系数试验仪不适用于粗颗粒土的缺陷,而且适用高应力范围。
In this paper, the large apparatus to measure static lateral pressure coefficient was introduced. The K_0 value of dry sand was tested by using the apparatus. The dry-sand test result was used to compare with the test of the water-bag typeK_0 oedometer. The friction of the sidewall produced during the experiment was amended, and the deviation caused by lateral expansion were also analyzed. The accuracy and effectiveness of the apparatus was validated. Coarse granular soil was tested by this apparatus. And the change of K_0 under various stress conditions was tested, which verified the applicability of the apparatus to coarse granular soil. It is convenient in operation, stable in performance, and precise in accuracy. It can be used to test the static lateral pressure coefficient of large practical size coarse grained soil, which is hard to get with the traditional instrument.
In this paper, the large apparatus to measure static lateral pressure coefficient was introduced. The K_0 value of dry sand was tested by using the apparatus. The dry-sand test result was used to compare with the test of the water-bag typeK_0 oedometer. The friction of the sidewall produced during the experiment was amended, and the deviation caused by lateral expansion were also analyzed. The accuracy and effectiveness of the apparatus was validated. Coarse granular soil was tested by this apparatus. And the change of K_0 under various stress conditions was tested, which verified the applicability of the apparatus to coarse granular soil. It is convenient in operation, stable in performance, and precise in accuracy. It can be used to test the static lateral pressure coefficient of large practical size coarse grained soil, which is hard to get with the traditional instrument.
引文
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[2]KOMORNIK A,ZEITLEN J G.An Apparatus for measuring lateral soil swelling pressure in the laboratory[C]//Proceedings of the 6th International Conference for Soil Mechanics and Foundation Engineering.[S.l.]:[s.n.],1965,1:278-281.
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[8]纠永志,黄茂松.超固结软黏土的静止土压力系数与不排水抗剪强度[J].岩土力学,2017,38(4):951-957.JIU Yong-zhi,HUANG Mao-song.Coefficient of earth pressure at rest and undrained shear strength of overconsolidated soft clays[J].Rock and Soil Mechanics,2017,38(4):951-957.
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[10]赵玉花,沈日庚,李青.软黏土侧压力系数K0阶段性特征研究[J].岩土力学,2008,29(5):1264-1268.ZHAO Yu-hua,SHEN Ri-geng,LI Qing.Research on staged characteristics of lateralpressure coefficient K0 of soft clay[J].Rock and Soil Mechanics,2008,29(5):1264-1268.
[11]肖先波.含气砂土静止侧压力系数的试验研究[J].水文地质工程地质,2010,37(2):76-78.XIAO Xian-bo.Experimental study on lateral pressure coefficient of gassy sand[J].Hydrogeology&Engineering Geology,2010,37(2):76-78.
[12]罗耀武,凌道盛,陈云敏,等.土体K0加卸载过程中水平应力变化研究[J].工业建筑,2010,40(7):56-58.LUO Yao-wu,LING Dao-sheng,CHEN Yun-min,et al.The change in horizontal stress of soils during K0loading-unloading[J].Industrial Construction,2010,40(7):56-58.
[13]李国维,胡坚,陆晓岑,等.超固结软黏土一维蠕变次固结系数与侧压力系数[J].岩土工程学报,2012,34(12):2198-2205.LI Guo-wei,HU Jian,LU Xiao-cen,et al.One-dimensional secondary consolidation coefficient and lateral pressure coefficient of overconsolidated soft clay[J].Chinese Journal of Geotechnical Engineering,2012,34(12):2198-2205.
[14]莫玮宏,陈晓平,罗庆姿.K0等比固结条件下软土的变形[J].岩土工程学报,2013,35(增刊2):798-803.MO Wei-hong,CHEN Xiao-ping,LUO Qing-zi.Deformation of soft soils under constant stress ration consolidation with K0[J].Chinese Journal of Geotechnical Engineering,2013,35(Supp.2):798-803.
[15]沈靠山.覆盖层砂卵砾石料静止侧压力系数研究[D].南京:河海大学,2009.SHENG Kao-shan.Steel-soil interface tests and numerical simulation of shear strength tests[D].Nanjing:Hohai University,2009.
[2]KOMORNIK A,ZEITLEN J G.An Apparatus for measuring lateral soil swelling pressure in the laboratory[C]//Proceedings of the 6th International Conference for Soil Mechanics and Foundation Engineering.[S.l.]:[s.n.],1965,1:278-281.
[3]BROOKER E Q,IRELAND H O.Earth pressure at-rest related to stress history[J].Canadian Geotechnical Journal,1965,2(1):1-15.
[4]ABDELHAMID S,KRIZEK R J.At-rest lateral earth pressure of consolidation clay[J].Journal of the Geotechnical Engineering Division,1976,102(7):721-738.
[5]BISHOP A W,HENKEL D J.The measurement of soil properties in the triaxial test[M].[S.l.]:Edward Arnold Ltd.,1957:71-73.
[6]姜朴,方涤华,宋永祥,等.K0固结三轴仪的研制与试验研究[J].岩土工程学报,1991,13(3):43-52.JIANG Pu,FANG Di-hua,SONG Yong-xiang,et al.Development and experiment of K0-consilidation triaxial apparatus[J].Chinese Journal of Geotechnical Engineering,1991,13(3):43-52.
[7]袁聚云,杨熙章,赵锡宏,等.K0固结真三轴仪的研制及试验研究[J].大坝观测与土工测试,1995,19(3):28-32.YUAN Ju-yun,YANG Xi-zhang,ZHAO Xi-hong,et al.Development and experiment of K0-consilidation true triaxial apparatus[J].Dam Observation and Geotechnical Tests,1995,19(3):28-32.
[8]纠永志,黄茂松.超固结软黏土的静止土压力系数与不排水抗剪强度[J].岩土力学,2017,38(4):951-957.JIU Yong-zhi,HUANG Mao-song.Coefficient of earth pressure at rest and undrained shear strength of overconsolidated soft clays[J].Rock and Soil Mechanics,2017,38(4):951-957.
[9]程海涛,刘保健,谢永利.压实黄土连续加载K0固结特性[J].岩石力学与工程学报,2007,26(增刊1):3203-3208.CHENG Hai-tao,LIU Bao-jian,XIE Yong-li.K0Consolidation characteristics of compacted loess under continuous loading[J].Chinese Journal of Rock Mechanics and Engineering,2007,26(Supp.1):3203-3208.
[10]赵玉花,沈日庚,李青.软黏土侧压力系数K0阶段性特征研究[J].岩土力学,2008,29(5):1264-1268.ZHAO Yu-hua,SHEN Ri-geng,LI Qing.Research on staged characteristics of lateralpressure coefficient K0 of soft clay[J].Rock and Soil Mechanics,2008,29(5):1264-1268.
[11]肖先波.含气砂土静止侧压力系数的试验研究[J].水文地质工程地质,2010,37(2):76-78.XIAO Xian-bo.Experimental study on lateral pressure coefficient of gassy sand[J].Hydrogeology&Engineering Geology,2010,37(2):76-78.
[12]罗耀武,凌道盛,陈云敏,等.土体K0加卸载过程中水平应力变化研究[J].工业建筑,2010,40(7):56-58.LUO Yao-wu,LING Dao-sheng,CHEN Yun-min,et al.The change in horizontal stress of soils during K0loading-unloading[J].Industrial Construction,2010,40(7):56-58.
[13]李国维,胡坚,陆晓岑,等.超固结软黏土一维蠕变次固结系数与侧压力系数[J].岩土工程学报,2012,34(12):2198-2205.LI Guo-wei,HU Jian,LU Xiao-cen,et al.One-dimensional secondary consolidation coefficient and lateral pressure coefficient of overconsolidated soft clay[J].Chinese Journal of Geotechnical Engineering,2012,34(12):2198-2205.
[14]莫玮宏,陈晓平,罗庆姿.K0等比固结条件下软土的变形[J].岩土工程学报,2013,35(增刊2):798-803.MO Wei-hong,CHEN Xiao-ping,LUO Qing-zi.Deformation of soft soils under constant stress ration consolidation with K0[J].Chinese Journal of Geotechnical Engineering,2013,35(Supp.2):798-803.
[15]沈靠山.覆盖层砂卵砾石料静止侧压力系数研究[D].南京:河海大学,2009.SHENG Kao-shan.Steel-soil interface tests and numerical simulation of shear strength tests[D].Nanjing:Hohai University,2009.