岩石力学与工程学报
巖石力學與工程學報
암석역학여공정학보
CHINESE JOURNAL OF ROCK MECHANICS AND ENGINEERING
2015年
z1期
2623-2631
,共9页
杨风威%李海波%齐三红%杨继华%张党立%姚阳
楊風威%李海波%齊三紅%楊繼華%張黨立%姚暘
양풍위%리해파%제삼홍%양계화%장당립%요양
边坡工程%应力波%岩质边坡%射线理论%放大效应
邊坡工程%應力波%巖質邊坡%射線理論%放大效應
변파공정%응력파%암질변파%사선이론%방대효응
slope engineering%stress wave%rock slope%ray theory%amplification effect
动荷载对岩体工程的影响本质上是应力波在岩体中传播和相互作用的过程。首先,依据弹性波几何射线理论,考虑边坡中坡顶、坡面2个自由面的影响,分析平面简谐P波自底部均匀入射时,岩质边坡中应力波场的组成,并通过叠加计算,得到坡体内质点振动速度放大系数的表达式,从理论角度揭示均质岩石边坡质点速度放大效应的机制。随后,探讨影响边坡质点速度峰值分布的关键因素,研究结果表明:P波和SV波在边坡中传播路径和传播速度不同,其到达某一质点的时间存在相位差,导致质点应力波场存在延时叠加,加之谐波振动的周期性,当边坡坡高或入射波频率大于一临界值时,坡体内质点速度放大系数呈现“节律性振荡”。临界坡高、临界频率值与岩石弹性模量成幂函数关系,临界坡高与频率、临界频率与坡高则成负幂函数关系。
動荷載對巖體工程的影響本質上是應力波在巖體中傳播和相互作用的過程。首先,依據彈性波幾何射線理論,攷慮邊坡中坡頂、坡麵2箇自由麵的影響,分析平麵簡諧P波自底部均勻入射時,巖質邊坡中應力波場的組成,併通過疊加計算,得到坡體內質點振動速度放大繫數的錶達式,從理論角度揭示均質巖石邊坡質點速度放大效應的機製。隨後,探討影響邊坡質點速度峰值分佈的關鍵因素,研究結果錶明:P波和SV波在邊坡中傳播路徑和傳播速度不同,其到達某一質點的時間存在相位差,導緻質點應力波場存在延時疊加,加之諧波振動的週期性,噹邊坡坡高或入射波頻率大于一臨界值時,坡體內質點速度放大繫數呈現“節律性振盪”。臨界坡高、臨界頻率值與巖石彈性模量成冪函數關繫,臨界坡高與頻率、臨界頻率與坡高則成負冪函數關繫。
동하재대암체공정적영향본질상시응력파재암체중전파화상호작용적과정。수선,의거탄성파궤하사선이론,고필변파중파정、파면2개자유면적영향,분석평면간해P파자저부균균입사시,암질변파중응력파장적조성,병통과첩가계산,득도파체내질점진동속도방대계수적표체식,종이론각도게시균질암석변파질점속도방대효응적궤제。수후,탐토영향변파질점속도봉치분포적관건인소,연구결과표명:P파화SV파재변파중전파로경화전파속도불동,기도체모일질점적시간존재상위차,도치질점응력파장존재연시첩가,가지해파진동적주기성,당변파파고혹입사파빈솔대우일림계치시,파체내질점속도방대계수정현“절률성진탕”。림계파고、림계빈솔치여암석탄성모량성멱함수관계,림계파고여빈솔、림계빈솔여파고칙성부멱함수관계。
Impact of dynamic load on rock mass engineering is essentially a process that stress waves propagate in rock mass and interact with each other. Firstly,based on the geometric ray theory of elastic wave transmission,the component of stress wave field in rock slope is analyzed considering the effect of slope surface and top surface, when uniform planar simple harmonic P waves normally impinge from the bottom. The expression of amplified coefficient of particle vibration velocity in slope is derived by wave field superimposition. As a result,the mechanism of velocity amplification effect in homogeneous rock slope is revealed in this way. Then the key influential factors of the distribution of peak velocity are worked out. Research shows that P and SV stress waves pass the same particle have phase difference and would superimpose with each other in time delay as different transmission pathes and velocitis in slope,so the particle velocity amplification coefficient presents“rhythmical oscillation” when the slope height or frequency of incident wave exceeds a critical value according to the regularity of harmonic wave. Additionally,the critical slope height or critical frequency presents power function relationship with the elastic modulus of rock;meanwhile the relation between critical slope height and frequency or between critical frequency and slope height is negative power function.