计算力学学报
計算力學學報
계산역학학보
CHINESE JOURNAL OF COMPUTATIONAL MECHANICS
2015年
2期
192-199
,共8页
董辉%马一跃%傅鹤林%王智超%陈铖
董輝%馬一躍%傅鶴林%王智超%陳鋮
동휘%마일약%부학림%왕지초%진성
滑坡%堆积碎石土%虚拟试验%细观参数%灵敏度分析
滑坡%堆積碎石土%虛擬試驗%細觀參數%靈敏度分析
활파%퇴적쇄석토%허의시험%세관삼수%령민도분석
landslide%alluvial gravel soil%virtual test%micro-parameters%sensitivity analysis
采用颗粒离散单元方法,实现任意形状块石的模拟,基于室内试验数据标定滑坡坡体物质的堆(残、坡)积碎石土的细观参数,并考虑试样尺度效应,对影响堆积碎石土宏观变形特征的细观参数进行虚拟试验敏感度分析。研究表明,①以三轴剪切试验获得测试数据并标定颗粒离散元细观参数具有相对误差在5%以内的可靠性;②虚拟模型1(101 mm ×200 mm)与模型2(300 mm ×600 mm)对标定的细观参数具有尺度效应,但其相对误差控制在9%以内;③离散元颗粒间的摩擦系数与碎石土的内摩擦角、抗剪强度及残余强度为非线性正相关,摩擦系数每增加0.1,峰值主应力差平均增加118.85 kPa ,残余强度平均增加90.44kPa;④围压越大,材料的剪胀性越弱,围压在100 kPa~500 kPa时,剪胀特征值 K在3~6之间变化,随着围压增加,模型破坏时的粘结力以近线性增加;⑤杨氏模量越大,碎石土的抗剪强度越大,但两者之间并不成线性关系,且不同杨氏模量对材料的残余强度没有显著影响。
採用顆粒離散單元方法,實現任意形狀塊石的模擬,基于室內試驗數據標定滑坡坡體物質的堆(殘、坡)積碎石土的細觀參數,併攷慮試樣呎度效應,對影響堆積碎石土宏觀變形特徵的細觀參數進行虛擬試驗敏感度分析。研究錶明,①以三軸剪切試驗穫得測試數據併標定顆粒離散元細觀參數具有相對誤差在5%以內的可靠性;②虛擬模型1(101 mm ×200 mm)與模型2(300 mm ×600 mm)對標定的細觀參數具有呎度效應,但其相對誤差控製在9%以內;③離散元顆粒間的摩抆繫數與碎石土的內摩抆角、抗剪彊度及殘餘彊度為非線性正相關,摩抆繫數每增加0.1,峰值主應力差平均增加118.85 kPa ,殘餘彊度平均增加90.44kPa;④圍壓越大,材料的剪脹性越弱,圍壓在100 kPa~500 kPa時,剪脹特徵值 K在3~6之間變化,隨著圍壓增加,模型破壞時的粘結力以近線性增加;⑤楊氏模量越大,碎石土的抗剪彊度越大,但兩者之間併不成線性關繫,且不同楊氏模量對材料的殘餘彊度沒有顯著影響。
채용과립리산단원방법,실현임의형상괴석적모의,기우실내시험수거표정활파파체물질적퇴(잔、파)적쇄석토적세관삼수,병고필시양척도효응,대영향퇴적쇄석토굉관변형특정적세관삼수진행허의시험민감도분석。연구표명,①이삼축전절시험획득측시수거병표정과립리산원세관삼수구유상대오차재5%이내적가고성;②허의모형1(101 mm ×200 mm)여모형2(300 mm ×600 mm)대표정적세관삼수구유척도효응,단기상대오차공제재9%이내;③리산원과립간적마찰계수여쇄석토적내마찰각、항전강도급잔여강도위비선성정상관,마찰계수매증가0.1,봉치주응력차평균증가118.85 kPa ,잔여강도평균증가90.44kPa;④위압월대,재료적전창성월약,위압재100 kPa~500 kPa시,전창특정치 K재3~6지간변화,수착위압증가,모형파배시적점결력이근선성증가;⑤양씨모량월대,쇄석토적항전강도월대,단량자지간병불성선성관계,차불동양씨모량대재료적잔여강도몰유현저영향。
The author uses the granular discrete element method to simulate the arbitrary shape stone and calibrate the mesoscopic parameters of gravel soil which was mainly constituted by weathering , unloading ,alluvial ,deluvial ,etc .Calibration is based on indoor triaxial compression experiments meas‐ured data at the same time considering the scale effect of sample .T his paper analyzed the sensitivity of the mesoscopic parameters w hich affection the accumulation of gravel soil macro deformation characteris‐tics through the virtual experiment .Studies have shown that :① The mesoscopic parameters of gravel soils based on indoor experimental calibration relative error is within 5% .② The size of the virtual experiment include model 1(101 mm × 200 mm) and the model 2(300 mm × 600 mm) .The model 2 to mesoscopi parameters calibration has scale effect ,but the relative error controlled within 9% .③ There are nonlinear positive relationships between the coefficient of friction of discrete element particles and the angle of internal friction ,and the shear strength ,and the residual strength .When the friction coefficient increased by 0 .1 ,the peak deviator stress average increased 118 .85 kPa and the residual strength average increased 90 .44 kPa .④ The greater the confining pressure ,the weaker the material dilatancy is ,when the confining pressure is changing betw een 100 kPa~500 kPa ,the dilatancy characteristic value K is obtained from 3 to 6 .The cohesive force of the damaged model nearly increases linearly as confining pressure increases .⑤ The greater the Young’s modulus ,the greater the shear strength of the gravel soil is ,but there is not a linear relationship between them .Moreover ,Young’s modulus does not affect residual strength of material significantly .