高含盐粉土的力学特性试验研究
|
摘要
高含盐粉土不仅含盐量较高,而且黏粒含量极低,粉粒含量高,级配不均匀,导致难以压实,强度低。为了了解此类特殊粉土的力学特性,在室内物理化学性质分析的基础上,进行原位旁压试验和原状土样的三轴试验,充分分析了高含盐粉土的力学性质。高含盐粉土的可溶性盐含量高达2.9%,主要是高硅、铝,水溶盐以Cl-和Na+为主,属氯盐碱性土。旁压试验结果表明,临塑压力可取350kPa、极限压力可取500kPa、旁压模量Em可取1750kPa、剪切模量Gm可以700kPa作为参考值。室内力学试验进一步分析表明,该土体具有较强的剪胀性,在轴向应变达到12%左右时,试样达到稳态状态。围压150kPa下的峰值强度能达到600～800kPa,残余强度也能达到450～550kPa。
Saline silt has many special characteristics, such as high salt content, extremely low content of clay and uneven gradation. Due to these special properties, it is hard to compact, so that the strength is very low. In order to understand mechanical characteristics of saline silt, in-situ pressuremeter tests (PMT) and triaxial tests of undisturbed samples were conducted after physicochemical analysis of this saline silt. The tests results show that the content of soluble salt is 2.9%, and the main ingredients are Cl and Na + . The silt belongs to alkaline soil with chlorine saline. The PMT test results indicate that pre-plastic pressure is 350 kPa and limit pressure is 500 kPa. In that area, pressuremeter and shear modulus can be adopted by 1 750 kPa and 700 kPa respectively. Laboratory test results represent that this soil have strong dilatancy effect. When the axis strain reaches to 12%, the sample will be close to steady state. The peak and residual strength can be achieved to 600～800 kPa and 450～550 kPa respectively when the confining pressure is 150 kPa.
Saline silt has many special characteristics, such as high salt content, extremely low content of clay and uneven gradation. Due to these special properties, it is hard to compact, so that the strength is very low. In order to understand mechanical characteristics of saline silt, in-situ pressuremeter tests (PMT) and triaxial tests of undisturbed samples were conducted after physicochemical analysis of this saline silt. The tests results show that the content of soluble salt is 2.9%, and the main ingredients are Cl and Na + . The silt belongs to alkaline soil with chlorine saline. The PMT test results indicate that pre-plastic pressure is 350 kPa and limit pressure is 500 kPa. In that area, pressuremeter and shear modulus can be adopted by 1 750 kPa and 700 kPa respectively. Laboratory test results represent that this soil have strong dilatancy effect. When the axis strain reaches to 12%, the sample will be close to steady state. The peak and residual strength can be achieved to 600～800 kPa and 450～550 kPa respectively when the confining pressure is 150 kPa.
引文
[1]李治平,王洪波.粉土地区公路病害与防治对策研究[J].交通科技,2003,(4):48-50.LI Zhi-ping,WANG Hong-bo.Study on highway distresses and engineering countermeasure[J].Transpor-tation Science&Technology,2003,(4):48-50.
[2]张权.粉土路基常见病害的预防与处治[J].科技咨询导报,2007,(24):175-176.
[3]朱志铎,刘松玉,孙海军.江苏徐宿地区粉土的基本性及加固方法研究[J].岩土力学,2004,25(7):1155-1158.ZHU Zhi-duo,LIU Song-yu,SUN Hai-jun.Study ofstabilized silt in Xu-Su area[J].Rock and Soil Mechanics,2004,25(7):1155-1158.
[4]杨占宝.黄河三角洲地震地质特征研究[硕士学位论文D].青岛:中国海洋大学,2003.
[5]景立平,崔杰,李立云,等.粉土液化的小型振动台试验研究[J].地震工程与工程振动,2004,24(3):145-151.JING Li-ping,CUI Jie,LI Li-yun,et al.Small shaking table modelling of silty soil liquefaction[J].Earthquake Engineering and Engineering Vibration,2004,24(3):145-151.
[6]马德翠,单红仙,周其健.黄河三角洲粉质土的动模量和阻尼比试验研究[J].工程地质学报,2005,13(3):353-360.MA De-cui,SHAN Hong-xian,ZHOU Qi-jian.Experi-mental study on shear modulus and damping ratio characteristics of silty soil in the delta of Yellow River[J].Journal of Engineering Geology,2005,13(3):353-360.
[7]贾永刚,史文君,单红仙,等黄河口粉土强度丧失与恢复过程现场振动试验研究[J].岩土力学,2005,26(3):351-358.JIA Yong-gang,SHI Wen-jun,SHAN Hong-xian,et al.In-situ test study on silt strength’s loss and recovery due to vibration load in the Yellow River mouth[J].Rock and Soil Mechanics,2005,26(3):351-358.
[8]YANG S L,SANDVENB R,GRANDE L.Instability of sand–silt mixtures[J].Soil Dynamics and Earthquake Engineering,2006,26(2-4):183-190.
[9]SANINA M V,WIJEWICKREME D.Cyclic shear response of channel-fill Fraser River Delta silt[J].Soil Dynamics and Earthquake Engineering,2006,26(9):854-869.
[10]中华人民共和国行业标准编写组.SL237-1999土工试验规程[S].北京:中国水利水电出版社,1999.
[11]中华人民共和国建设部.GB50021-2001岩土工程勘察规范[S].北京:中国建筑工业出版社,2002.
[12]《岩土工程手册》编写委员会.岩土工程手册[M].北京:中国建筑工业出版社,1994.
[13]汪稔,胡建华.旁压试验在苏通大桥地质勘察工程中的应用[J].岩土力学,2003,24(6):887-891.WANG Ren,HU Jian-hua.Application of pressuremeter test to estimating intensity parameters in geological exploration for Sutong Bridge[J].Rock and Soil Mechanics,2003,24(6):887-891.
[14]孟高头.土体原位测试机制、方法及工程应用[M].北京:地质出版社,1997.
[2]张权.粉土路基常见病害的预防与处治[J].科技咨询导报,2007,(24):175-176.
[3]朱志铎,刘松玉,孙海军.江苏徐宿地区粉土的基本性及加固方法研究[J].岩土力学,2004,25(7):1155-1158.ZHU Zhi-duo,LIU Song-yu,SUN Hai-jun.Study ofstabilized silt in Xu-Su area[J].Rock and Soil Mechanics,2004,25(7):1155-1158.
[4]杨占宝.黄河三角洲地震地质特征研究[硕士学位论文D].青岛:中国海洋大学,2003.
[5]景立平,崔杰,李立云,等.粉土液化的小型振动台试验研究[J].地震工程与工程振动,2004,24(3):145-151.JING Li-ping,CUI Jie,LI Li-yun,et al.Small shaking table modelling of silty soil liquefaction[J].Earthquake Engineering and Engineering Vibration,2004,24(3):145-151.
[6]马德翠,单红仙,周其健.黄河三角洲粉质土的动模量和阻尼比试验研究[J].工程地质学报,2005,13(3):353-360.MA De-cui,SHAN Hong-xian,ZHOU Qi-jian.Experi-mental study on shear modulus and damping ratio characteristics of silty soil in the delta of Yellow River[J].Journal of Engineering Geology,2005,13(3):353-360.
[7]贾永刚,史文君,单红仙,等黄河口粉土强度丧失与恢复过程现场振动试验研究[J].岩土力学,2005,26(3):351-358.JIA Yong-gang,SHI Wen-jun,SHAN Hong-xian,et al.In-situ test study on silt strength’s loss and recovery due to vibration load in the Yellow River mouth[J].Rock and Soil Mechanics,2005,26(3):351-358.
[8]YANG S L,SANDVENB R,GRANDE L.Instability of sand–silt mixtures[J].Soil Dynamics and Earthquake Engineering,2006,26(2-4):183-190.
[9]SANINA M V,WIJEWICKREME D.Cyclic shear response of channel-fill Fraser River Delta silt[J].Soil Dynamics and Earthquake Engineering,2006,26(9):854-869.
[10]中华人民共和国行业标准编写组.SL237-1999土工试验规程[S].北京:中国水利水电出版社,1999.
[11]中华人民共和国建设部.GB50021-2001岩土工程勘察规范[S].北京:中国建筑工业出版社,2002.
[12]《岩土工程手册》编写委员会.岩土工程手册[M].北京:中国建筑工业出版社,1994.
[13]汪稔,胡建华.旁压试验在苏通大桥地质勘察工程中的应用[J].岩土力学,2003,24(6):887-891.WANG Ren,HU Jian-hua.Application of pressuremeter test to estimating intensity parameters in geological exploration for Sutong Bridge[J].Rock and Soil Mechanics,2003,24(6):887-891.
[14]孟高头.土体原位测试机制、方法及工程应用[M].北京:地质出版社,1997.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心