振动与冲击
振動與遲擊
진동여충격
JOURNAL OF VIBRATION AND SHOCK
2014年
7期
51-57
,共7页
吴文兵%蒋国盛%窦斌%王奎华%黄生根
吳文兵%蔣國盛%竇斌%王奎華%黃生根
오문병%장국성%두빈%왕규화%황생근
嵌岩桩%纵向振动阻抗%嵌岩特性%横向惯性效应%Laplace变换
嵌巖樁%縱嚮振動阻抗%嵌巖特性%橫嚮慣性效應%Laplace變換
감암장%종향진동조항%감암특성%횡향관성효응%Laplace변환
rock-socketed pile%vertical dynamic impedance%rock-socketed characteristic%lateral inertial effect%Laplace transformation
基于平面应变模型和Rayleigh-Love杆模型,建立了成层地基中嵌岩桩纵向振动的计算模型和控制方程,结合边界条件和初始条件,采用Laplace变换技术和阻抗函数递推技术求得了任意荷载作用下嵌岩桩桩顶纵向振动复阻抗的频域解析解,并在桩基础动力设计关注的低频范围内详细讨论了嵌岩特性对嵌岩桩桩顶纵向振动阻抗的影响。结果表明:对于同一上覆土层,动刚度随着嵌岩深度的增大而减小,而动阻尼则逐渐增大;对于嵌岩桩段半径等于桩半径的嵌岩桩,动刚度和动阻尼均随着桩身截面半径的增大而增大,对于嵌岩桩段半径小于桩半径的嵌岩桩,随着嵌岩桩段半径的减小,动刚度逐渐减小,动阻尼逐渐增大;随着岩层特性变好,动刚度逐渐增大,动阻尼逐渐减小。
基于平麵應變模型和Rayleigh-Love桿模型,建立瞭成層地基中嵌巖樁縱嚮振動的計算模型和控製方程,結閤邊界條件和初始條件,採用Laplace變換技術和阻抗函數遞推技術求得瞭任意荷載作用下嵌巖樁樁頂縱嚮振動複阻抗的頻域解析解,併在樁基礎動力設計關註的低頻範圍內詳細討論瞭嵌巖特性對嵌巖樁樁頂縱嚮振動阻抗的影響。結果錶明:對于同一上覆土層,動剛度隨著嵌巖深度的增大而減小,而動阻尼則逐漸增大;對于嵌巖樁段半徑等于樁半徑的嵌巖樁,動剛度和動阻尼均隨著樁身截麵半徑的增大而增大,對于嵌巖樁段半徑小于樁半徑的嵌巖樁,隨著嵌巖樁段半徑的減小,動剛度逐漸減小,動阻尼逐漸增大;隨著巖層特性變好,動剛度逐漸增大,動阻尼逐漸減小。
기우평면응변모형화Rayleigh-Love간모형,건립료성층지기중감암장종향진동적계산모형화공제방정,결합변계조건화초시조건,채용Laplace변환기술화조항함수체추기술구득료임의하재작용하감암장장정종향진동복조항적빈역해석해,병재장기출동력설계관주적저빈범위내상세토론료감암특성대감암장장정종향진동조항적영향。결과표명:대우동일상복토층,동강도수착감암심도적증대이감소,이동조니칙축점증대;대우감암장단반경등우장반경적감암장,동강도화동조니균수착장신절면반경적증대이증대,대우감암장단반경소우장반경적감암장,수착감암장단반경적감소,동강도축점감소,동조니축점증대;수착암층특성변호,동강도축점증대,동조니축점감소。
Based on the plane strain model and Reyleigh-Love rod model,the calculating model and governing equation of a rock-socketed pile embedded in layered soil was established during an arbitrary vertical exciting force acting on the pile head.Combining the boundary conditions and initial conditions,the analytical solution to vertical dynamic impedance at the head of the rock-socketed pile was derived by means of Laplace transformation and the impedance function transfer method.By means of parametric study method,the influence of rock-socketed characteristics on the vertical dynamic impedance at the head of the rock-socketed pile was investigated within a lower frequency range.The results showed that for a certain depth of overlaying soil,the dynamic stiffness decreases with increase in the rock-socketed length while the dynamic damping increases with increase in rock-socketed length;when the radius of rock-socketed segment is equal to pile radius the dynamic stiffness and dynamic damping increase with increase in pile radius;when the radius of rock-socketed segment is less than pile radius,the dynamic stiffness decreases with decrease in radius of rock-socketed segment,but the dynamic damping increases with decrease in radius of rock-socketed segment;the dynamic stiffness increases and the dynamic damping decreases with increase in shear wave velocity of bedrock.