在生产实践中,淤泥质土不易取样、制样,很难获得较多的参数。通过对淤泥质土进行多级三轴试验,探讨了多级三轴试验在实际操作中的可行性及多级三轴试验中应注意的关键问题。在多级三轴试验中,级差应控制在30 kPa,级数为3级,固结时间依次为10 min和20 min。破坏标准第1级破坏标准为轴向应变达到12%和轴向压力稳定两者的先发生者;第2级和第3级破坏标准均为轴向压力稳定。通过试验证明淤泥质土的多级三轴试验克服了淤泥质土取样、制样的困难,获得的参数黏聚力略大,内摩擦角略小,但其结果仍在合理范围之内,未发生较大的偏差,经过修正可以有效地进行使用。该方法具有较好的应用前景,是一种经济可行的试验方法。
Abstract
It is troublesome to collect and prepare specimens of silty soil in practice, posing difficulties to obtaining parameters. In this paper we discuss the feasibility and pivotal problems of multilevel tri-axial test on silty soil. We summarize that the number of loading steps is 3 and the disparity among steps should be controlled within 30kPa. The time of consolidation are 10 minutes and 20 minutes respectively. As for failure criterion, the first stage failure is determined to be when axial strain reaches 12% or when axial pressure gets stable; the second and third stage failure are both determined when axial pressure gets stable. The tests in this paper prove that multilevel triaxial test could overcome the difficulties of collecting and preparing silty soil specimens, and the obtained parameters are reasonable with slight deviationsthe cohesion is slightly larger and internal friction angle is slightly smaller. These parameters could be adopted after correction, and the multilevel triaxial test is proved to be an economical and feasible method.
关键词
淤泥质土 /
强度再生 /
多级三轴试验 /
级数级差 /
固结时间 /
破坏标准 /
抗剪强度
Key words
silty soil /
strength recycled /
multilevel triaxial test /
number and disparity of loading steps /
time of consolidation /
failure criterion /
shear strength
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
[1] SL237—1999,土工试验规程.北京:中国水利水电出版社,1999.(SL237—1999,Specification of Soil Test.Beijing: China Water Power Press,1999.(in Chinese))
GB/T50123—1999,土工试验方法标准.北京:中国建筑工业出版社,2000. (GB/T50123—1999, Standard for Soil Test Method. Beijing: China Architecture and Building Press, 2000. (in Chinese))
辜天赐.对“一个试样多级加荷三轴试验”的几点认识.大坝观测与土工测试,1992,(2):47-48. (GU Tian-ci. Several Understanding of Multilevel Triaxial Loading Test for a Sample. Dam Observation and Geotechnical Tests, 1992, (2): 47-48. (in Chinese))
黄志全,刘 娅,刘 灿,等.结构性对淤泥质土强度影响试验研究.人民黄河,2010,32(11):98-99. (HUANG Zhi-quan, LIU Ya, LIU Can, et al. Experimental Study on the Impact of Structural Muddy Soil Strength. Yellow River, 2010,32(11):98-99. (in Chinese))
车承国.对一个试样多级加荷三轴剪切试验的探讨.电力勘测设计,2003,(1):33-36. (CHE Cheng-guo. Discussion on Triaxial Multilevel Shear Loading Test for a Sample. Electric Power Survey & Design, 2003, (1): 33-36. (in Chinese))
何 群.软土抗剪强度与固结度关系的试验研究.铁道科学与工程学报,2005,2(2):51-55. (HE Qun. Experimental Study on Relationship between Soft Soil’s Shear Strength and Degree of Consolidation. Journal of Railway Science and Engineering, 2005, 2(2):51-55. (in Chinese))
SD 128—84,土工试验规程. 北京:中国水利水电出版社,1984. (SD 128—84, Specification of Soil Test. Beijing: China Water Power Press, 1984. (in Chinese))
郑 丹.三轴试验单试样多级加荷的适用性分析.土工基础,2005,19(5):75-77. (ZHENG Dan. Applicability of Multi-level Loading for Triaxial Single Testing. Soil Engineering and Foundation, 2005, 19(5):75-77. (in Chinese))
PDF(1637 KB)
