高土石坝动力反应研究
|
摘要
针对复杂超高应力条件下粗粒筑坝材料的动力变形特性较复杂问题,采用反映粗粒筑坝材料振动硬化特性的动力模型及考虑初始固结围压影响的粗粒料动力残余变形模型,利用试验动孔压比与动剪应力比关系曲线计算动孔压的方法研究了高土石坝的动力反应特性。计算结果表明,大坝遭遇场地谱人工波的最大水平向加速度反应为3.97 m/s2,位于坝顶部位;竖直向地震永久变形占坝高的0.17%;受水库蓄水的影响,坝体上游坡的永久变形较下游坡更明显;地震过程中坝体心墙料、反滤料和坝基砂层的动孔压比均小于0.3,不会发生液化;建造于基岩上的高土石坝具有良好的抗震性能。
The dynamic deformation characteristics of coarse dam material are extremely complex under the situation of high stress.Dynamic constitutive model reflecting the vibration hardening of materials,dynamic model of the residual deformation of coarse granule considering the effect of initial consolidation confining stress,and the relationship between the pore pressure ratio and the dynamic shear stress ratio obtained in test are used to study the seismic response characteristics of high earth rockfill dam.The results show that maximum horizontal acceleration of the dam is 3.97 m/s2 when suffering artificial wave synthesized by site-specific response spectrum,which appears at dam crest;vertical permanent deformation is 0.17% of dam height;permanent deformation of upstream slope is larger than that of downstream slope because of reservoir filling;dynamic pore pressure ratio of dam core material,filter material and the foundation sand are smaller than 0.3,so the liquefaction does not occur.Thus,the seismic performance of high earth rockfill dam built upon bedrock has good anti-seismic property.
The dynamic deformation characteristics of coarse dam material are extremely complex under the situation of high stress.Dynamic constitutive model reflecting the vibration hardening of materials,dynamic model of the residual deformation of coarse granule considering the effect of initial consolidation confining stress,and the relationship between the pore pressure ratio and the dynamic shear stress ratio obtained in test are used to study the seismic response characteristics of high earth rockfill dam.The results show that maximum horizontal acceleration of the dam is 3.97 m/s2 when suffering artificial wave synthesized by site-specific response spectrum,which appears at dam crest;vertical permanent deformation is 0.17% of dam height;permanent deformation of upstream slope is larger than that of downstream slope because of reservoir filling;dynamic pore pressure ratio of dam core material,filter material and the foundation sand are smaller than 0.3,so the liquefaction does not occur.Thus,the seismic performance of high earth rockfill dam built upon bedrock has good anti-seismic property.
引文
[1]Martin G R.Effects of System Compliance on Liq-uefaction Tests[J].Journal of Geotechnical Engi-neering Division,1978,104(4):463-480.
[2]沈珠江.一个计算砂土液化变形的等价粘弹性模型[M].北京:中国建筑工业出版社,1986.
[3]陈生水,沈珠江.钢筋混凝土面板堆石坝的永久变形分析[J].岩土工程学报,1990,12(3):66-72.
[4]郦能惠,沈珠江.土石坝工程研究新进展[J].水利水电科技进展,1999,19(4):6-9.
[5]李湛.土石坝地震永久变形及抗震数值分析方法研究[D].大连:大连理工大学,2005.
[6]朱晟,周建波.粗粒筑坝材料的动力变形特性[J].岩土力学,2010,31(5):1 375-1 380.
[7]顾淦臣.土石坝地震工程[M].南京:河海大学出版社,1989.
[8]河海大学.300 m级土质心墙堆石坝关键技术研究:坝体动力反应分析与抗震安全评价[R].南京:河海大学,2008.
[2]沈珠江.一个计算砂土液化变形的等价粘弹性模型[M].北京:中国建筑工业出版社,1986.
[3]陈生水,沈珠江.钢筋混凝土面板堆石坝的永久变形分析[J].岩土工程学报,1990,12(3):66-72.
[4]郦能惠,沈珠江.土石坝工程研究新进展[J].水利水电科技进展,1999,19(4):6-9.
[5]李湛.土石坝地震永久变形及抗震数值分析方法研究[D].大连:大连理工大学,2005.
[6]朱晟,周建波.粗粒筑坝材料的动力变形特性[J].岩土力学,2010,31(5):1 375-1 380.
[7]顾淦臣.土石坝地震工程[M].南京:河海大学出版社,1989.
[8]河海大学.300 m级土质心墙堆石坝关键技术研究:坝体动力反应分析与抗震安全评价[R].南京:河海大学,2008.
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