团粒尺寸对饱和红黏土动力特性影响试验研究  

Experimental study on the effect of aggregate size on the dynamic characteristics of saturated red clay

作　　者：陈波 杨天辰 金盼 CHEN Bo;YANG Tianchen;JIN Pan(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,Anhui,China;College of Civil Engineering and Architecture,Quzhou University,Quzhou 324000,Zhejiang,China)

机构地区：[1]安徽建筑大学土木工程学院,安徽合肥230601 [2]衢州学院建筑工程学院,浙江衢州324000

出　　处：《地震工程学报》2025年第2期270-280,共11页China Earthquake Engineering Journal

基　　金：浙江省自然科学基金资助项目(LZY21D020001);衢州市重点科技攻关资助项目(2022K93,2023K220)。

摘　　要：广泛用于路基填料的红黏土容易胶结成不同团粒结构,从而对土体的动力特性产生重要影响。为探究团粒尺寸对饱和红黏土动力特性的影响,运用GDS动三轴仪对最大团粒尺寸D_(max)分别为5.0、2.0和0.5 mm制备的饱和压实样,开展不同循环应力比的循环荷载不排水三轴试验,以探究土体的动轴向应变、动弹模量以及阻尼比随团粒尺寸的演化规律。具体结论如下:(1)累积动轴向应变随循环次数增多而增大的演化规律主要集中于循环次数为200次的范围内;累计动轴向应变随循环应力比的增大呈指数型增长。(2)考虑容许循环应力比之前,越大团粒尺寸制备试样所产生的累积动轴向应变越大;考虑容许循环应力比之后,越大团粒尺寸制备试样所产生的累计动轴向应变反而越小。(3)不同团粒尺寸试样在同一循环应力比作用下,土体动弹模量和阻尼比随振动次数的增加逐渐趋于一致,表明团粒尺寸只在循环荷载作用初期对动弹模量和阻尼比产生重要影响。The use of red clay,a widely-used material for subgrade-filling,easily results in the formation of an aggregate structure with different sizes,which means it has an important influence on the dynamic characteristics of soil.With the goal of investigating the effect of aggregate size on the dynamic characteristics of saturated red clay,a series of consolidation-undrained dynamic triaxial tests under different cyclic stress ratios were conducted in this study on compacted specimens prepared with different aggregate sizes(D_(max)=5.0,2.0 and 0.5 mm)using the dynamic triaxial apparatus GDS.The evolution of dynamic axial strain,dynamic elastic modulus,and damping ratio with aggregate size was analyzed.Several key findings are obtained.(1)The obvious increase in cumulative dynamic axial strain with increasing cyclic number is concentrated within the first 200 cycles,and such axial strain exhibits exponential growth as the cyclic stress ratio increases.(2)The more cumulative dynamic axial strain is observed from specimens prepared with larger aggregate sizes before the allowable cyclic stress ratio.In comparison,more cumulative dynamic axial strain is observed from specimens prepared with smaller aggregate sizes after the allowable cyclic stress ratio.(3)Under the same cyclic stress ratio,the dynamic elastic modulus and damping ratio of specimens with different aggregate sizes,almost align with the same growth tendency as the vibration times increased,thus indicating that the influence of aggregate size on dynamic elastic modulus and damping ratio is only obvious in the initial stage of cyclic loading.

关 键 词：饱和红黏土 动三轴试验 团粒尺寸 循环应力比 动力特性 

分 类 号：P319.56[天文地球—固体地球物理学]