瑞雷面波在注浆加固及强夯地基检测中的应用

瑞雷面波法勘探是一种浅层物探勘探方法,可应用于公路、铁路、海港码头等多个工程领域,如工程勘探,岩土原位测试,地基加固效果评价以及地基评估等方面。瞬态瑞雷面波法能够快速检测地层的剪切波速度,进行地层划分、评价地基场地类型、分析地基处理效果。本文介绍了瑞雷面波法勘探的原理以及现场工作参数的选取,并通过检测地基注浆加固效果以及检测强夯地基加固效果应用实例,说明其在工程中的应用效果。     

瞬态面波勘探技术在岩土工程勘察中的应用

面波作为地质灾害的一种表征现象,具有很强的干扰性,但利弊并存,瞬态面波勘探技术正是利用面波的频散特性和传播效率创新而来的一种新型岩土勘察技术,其通过面波自身特质与岩土物理力学性质的相关性来解决工程地质中存在的诸多问题,且具备勘察精度高、效率快、场地要求低等优势性,目前被广泛应用在岩土工程勘察中,本文以面波特性及相关原理为切入点,分析瞬态面波勘探技术的工作方法及数据处理,并结合实际工程实例进行应用分析,以此为相关研究提供理论参考。     

某拟建修造船厂工程波浪分析

依据秦皇岛海洋站34年实测资料统计分析出的不同重现期的波浪要素,针对某拟建修造船厂工程总平面布置方案,利用TK-2D波浪数学模型及MIKE21的BW方程波浪数学模型,对工程建成前后的波浪场进行模拟.确定了工程区域各等深线处的设计波要素,论证了船厂码头和不同的防波堤、进港航道平面方案布置对港内的泊稳条件、拟建码头前的波浪变形情况以及波浪变化对码头作业天数的影响.模型中考虑了波浪的折射、绕射、反射、底部损耗等因素,为工程设计提供依据.     

新疆努尔加水库工程地质评价

努尔加水库是三屯河上的一座控制性水利枢纽工程,准确评估区域工程地质概况是保证水库兴建和安全运行的可靠保障。文章通过评价努尔加水库地形地貌、地层岩性、地质条件等,以期为类似工程提供参考。     

椭圆余弦波理论在波峰面上升高度计算中的应用

在开敞式高桩码头的设计中,波峰面上升高度是确定上部结构顶面高程的重要因素。针对波峰面上升高度的计算理论问题,对二阶斯托克斯波和椭圆余弦波理论进行论述。结合西非某工程案例,采用不同理论计算各控制点的波要素。结果表明:在长周期波浪作用海域,计算波峰面上升高度前应首先计算相对水深,当d0.125L时,采用二阶斯托克斯波理论计算结果误差较大,采用椭圆余弦波理论计算结果更符合实际情况。     

湖南某大桥桥址工程地质勘察与评价

通过采用不同的工程地质勘察方法,对湖南某公路大桥的工程地质条件和水文地质条件进行了调查,获取了桥址区的地形地貌、地层岩性、水文地质及场地地震效应等;对桥址区的岩土进行了分类,有针对性的进行了室内试验和原位测试,并对测试结果进行了分析,获取了主要岩土层的物理力学性质指标;在此基础上,对桥址区场地及地基的稳定性、水文地质条件和工程地质条件进行了评价,提出了桥基的持力层及基础型式,给出了各岩土层的地基承载力及桩侧摩擦力等设计参数,为后期桥基设计及施工提供了依据。     

港珠澳大桥岛隧工程水文地质特征分析

为了查明港珠澳大桥隧道区的水文地质条件,根据水文气象资料、水的化学分析、抽水试验、CPTU(测孔压静力触探),并结合地形地貌、地层情况、土的物理力学性质,对港珠澳大桥岛隧工程水文地质特征进行分析。分析结果表明：该场区地表水为海水,松散岩类孔隙水为弱承压水,基岩裂隙水与松散岩类孔隙水形成直接水力联系。该区域属于典型的三角洲入海口地带,其工程水文地质特征具有独特性与代表性,可以为类似的其它三角洲入海口地带的工程水文地质特征分析提供经验。     

雷州半岛老粘性土的工程特性研究

雷州半岛区域广泛分布的老粘性土层,该土层埋深较浅,分布稳定,该层老粘性土年代久远,结构强度高。结合雷州电厂海域工程勘察成果,文中从该工程区域地层分布,该老粘性土工程特殊性,形成工程特性的成因及工程应用中注意的事项及解决方法几个方面进行了分析研究,为该种土层进行港口工程建设项目提供了地质依据。     

多道瞬态面波技术在港口工程勘察中的应用

介绍多道瞬态面波法勘探的基本原理,以及该技术应用于港口工程勘察中解决岩土层的划分、地基土工程特性的分析、抗震设计参数的提供、地基加固效果的评价等一系列问题.     

风浪谱模型在滇池码头工程中的应用

针对滇池的波浪特性,选用基于波能平衡方程与波作用守恒方程的风浪谱模型建立滇池波浪数学模型。数学模型计算结果与经验公式结果相比较,两者吻合较好,验证了计算模型的可靠性,并进一步计算了设计风场下滇池拟建码头工程区域工程前后的风浪场情况,为滇池古渡码头工程设计方案的优选提供依据。研究结果表明:工程受偏N方向风浪影响较大,而受常浪向WSW影响较小;浮桥为"L"型双梳式栈桥平面布置形式的风浪挡浪效果较好,优于"T"字型双梳式栈桥平布置形式。     

波浪对潮流影响的数值模拟及其应用

文章将水动力因素分为潮流特征周期与波浪特征周期两部分,建立了考虑波浪影响的潮流方程。通过考虑波浪引起的辐射应力、表面和底部边界层、Stokes漂流以及Coriolis波浪应力等因素,利用数值方法分析了波浪对潮流场的影响,并将其应用到渤海区域中,分析渤海内波浪对于潮流的影响。     

两层流体中潜体的不定常运动兴波

本文应用Ｌａｐｌａｃｅ变换方法和基元波叠加的概念对两层流体中孤立点源和细长潜体的不定常线性兴波问题进行了探讨,给出了自由面和内界面的波型及兴波阻力的算例结果。     

紧致插值曲线CIP方法及其应用

波浪与建筑物的相互作用过程会涉及到波浪破碎、水气掺混和结构物的动力响应等复杂过程,对数值算法提出了更高要求。文章基于紧致插值曲线CIP（Constrained Interpolation Profile）方法建立了可模拟波浪破碎、翻滚等自由面大变形流动问题的数学模型。模型以CIP方法为流场基本求解器,离散了纳维—斯托克斯（Navier-Stokes：N-S）方程,同时还以CIP方法捕捉了自由面,通过多相流理论描述了流—固—气之间的相互作用。对强非线性自由表面流动问题的典型算例溃坝问题开展了数值模拟,并通过与他人实验结果的比较验证了模型的有效性。最后开展了极端波浪对浮式结构冲击过程的模拟,准确地预测了甲板上浪和结构的动力响应等问题。     

采用THOBEM方法研究波流与结构物相互作用的数值模拟(英文)

To study wave-current actions on 3-D bodies a time-domain numerical model was established using a higher-order boundary element method (HOBEM). By assuming small flow velocities, the velocity potential could be expressed for linear and higher order components by perturbation expansion. A 4th-order Runge-Kutta method was applied for time marching. An artificial damping layer was adopted at the outer zone of the free surface mesh to dissipate scattering waves. Validation of the numerical method was carried out on run-up, wave exciting forces, and mean drift forces for wave-currents acting on a bottom-mounted vertical cylinder. The results were in close agreement with the results of a frequency-domain method and a published time-domain method. The model was then applied to compute wave-current forces and run-up on a Seastar mini tension-leg platform.     

Numerical simulation of three-dimensional breaking waves

Three-dimensional (3D) wave breaking around bodies of complex geometry has been numerically investigated by use of two types of Navier-Stokes solvers, namely the finite-difference and the finite-volume methods employing rectangular and curvilinear coordinate systems, respectively. Both methods employ the density-function technique to capture the free surface location and can cope with complicated free surface configurations such as breaking waves. The accuracy of the density-function method is examined through the comparison with experimental results, and it is confirmed to be satisfactory when the grid spacing and the time increment are sufficiently small. New computational methods are applied to several problems including 3D breaking waves around ships and wave diffraction around offshore structures. The computed results show good agreement with experimental results indicating that wave breaking phenomena are successfully simulated. The qualitative accuracy, however, could be improved by including the dissipating effect of breaking waves.     

Numerical simulation of nonlinear wave force on a quasi-ellipse caisson

A three dimensional numerical model of nonlinear wave action on a quasi-ellipse caisson in a time domain was developed in this paper. Navier-Stokes equations were solved by the finite difference method, and the volume of fluid (VOF) method was employed to trace the free surface. The partial cell method was used to deal with the irregular boundary typical of this type of problem during first-time wave interaction with the structure, and a satisfactory result was obtained. The numerical model was verified and used to investigate the effects of the relative wave height H/d, relative caisson width kD, and relative length-width ratio B/D on the wave forces of the quasi-ellipse caisson. It was shown that the relative wave height H/d has a significant effect on the wave forces of the caisson. Compared with the non-dimensional inline wave force, the relative length-width ratio B/D was shown to have significant influence on the non-dimensional transverse wave force.     

绕船体粘性自由面流动的数值计算

考虑自由面的船舶粘性流动计算由于其复杂性和对计算机硬伯的较高要求，只是到了最近几年才得到较大发展，而在国内尚属起步阶段。本文使用VOF方法计算了绕Wigley船型的粘性自由面流动，流模式选择了SSTκ-ω模型。计算获得了船体上波形以及船波等值线图，同时考察了三个不同横截面上的流动状况。计算得到的阻力还和发表的试验结果作了对比，结果令人鼓舞。     

潜艇内波尾迹物理场在海面映波量值的确定

采用Tuck的方法,具体计算了国外有代表性的潜艇在海洋中内波尾迹物理场垂直上传到海面上的映波的量值,并对映波波幅随艇半径、艇长度、艇速和艇后距的关系作了分析.     

考虑定常兴波影响的辐射问题去奇Rankine源方法数值计算

随着中高速船舶在海洋资源开发中的广泛应用,航速对船舶在波浪中摇荡运动的影响受到重视。本文基于势流理论,采用非均匀有理B样条(NURBS)表达物面,应用去奇Rankine源方法求解流场速度势;推导了兴波问题的二阶近似非线性自由面边界条件,以及考虑二阶近似非线性兴波影响的辐射速度势的线性自由面和物面边界条件。本文编程首先数值计算了Wigley船型的近似非线性兴波问题,将计算的线性和非线性兴波阻力系数与文献结果做了比较;然后数值计算了计及线性定常兴波影响的下潜圆球有航速辐射问题,将计算的附加质量和阻尼系数与文献结果比较。本文计算结果与文献结果吻合程度较好,验证了本文数值计算方法的有效性。文中还给出了兴波波形和辐射波形。     

Wave scattering by undulating bed topography in a two-layer ocean

The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of waves propagating at both the free surface of the upper layer and the interface between the two layers. Due to a wave train of a particular mode incident on an obstacle which is bottom-standing on the lower layer, reflected and transmitted waves of both modes are created by the obstacle. For small undulations on the bottom of the lower layer, a perturbation method is employed to obtain first-order reflection and transmission coefficients of both modes for incident wave trains of again both modes in terms of integrals involving the bed-shape function. For sinusoidal undulations, numerical results are presented graphically to illustrate the energy transfer between the waves of different modes by the undulating bed. U. BASU was born in 1949. She is a professor in the Department Applied Mathematics, Calcutta University, India. Her current research interests include water wave problems, continuum mechanics, etc.