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1.
透空式水平板波浪上托力分布 总被引：9，自引：3，他引：9
通过系列模型试验，对波浪上托力沿板宽分布进行了详细分析，提出对于透空式平板结构，发生较大冲击压强或上托力的分布主要分为均布型和局部冲击型两类，由此得到压强分布的计算公式。大量试验资料表明，该公式与实验值有着较好的一致性。 相似文献
2.
通过系列模型试验,对透空水平板下波浪总上托力进行了研究,结果表明：平板下最大总上托力并不与最大冲击压强同步发生。为此,依据试验结果对波浪总上托力产生机理和影响因素进行详细分析,提出透空水平板波浪最大总上托力的计算公式,试验结果表明,该公式与实验值有着较好的一致性。 相似文献
3.
透空式水平板波浪上托力冲击压强试验研究 总被引：8，自引：1，他引：7
首先对以往波浪作用下透空式平板上托力研究进行了回顾,在此基础上,通过系列模型试验,对波浪上托力产生的机理进行了详细的分析和论述,认为透空式平板下波浪上托力主要由一个迅速上升的冲击压强和一个缓慢变化的压强构成,其中冲击压强通常远大于缓变压强,起主导作用,影响其大小的最直接因素为几何因素(即波浪冲击角)、动力因素(包括波高、波速等)和空气垫层因素,由此通过对各影响因素的分析,得到最大冲击压强计算公式,大量试验资料表明,该公式与实验值有着较好的一致性。 相似文献
4.
透空式水平板波浪上托力计算方法 总被引：8，自引：2，他引：6
在透空式平板波浪上托力试验研究基础上,针对实际工程应用要求,提出相对简便的透空式平板下波浪局部上托力和最大总上托力计算方法,包括上托力大小、分布宽度和发生位置。对具体工程实例的计算结果表明,该方法与实验值有着较好的一致性。 相似文献
5.
在水槽中进行了几种不同坡度的斜坡平台上规则波作用下直墙波浪力试验，系统分析了直墙上相对最大压强和相对最大总力，给出了它们之间的比较关系。还进行了不同坡度的不规则波模型试验，并讨论了波浪力之间的特性。结果表明采用1：10、1：15的斜坡与平台相结合的试验室模拟，可得到与平底地形相近的直墙波浪力。 相似文献
6.
通过物理模型试验研究中国《海港水文规范》(JTJ213-98)中斜坡式防波堤顶部胸墙波浪力计算公式在深水情况下的适用性.试验测量4种不同水深波浪作用下斜坡堤顶部胸墙的波浪力和作用高度.通过对胸墙迎浪面的波浪压强分布、总水平作用力和波浪作用高度的试验结果与《海港水文规范》结果的对比分析,发现胸墙迎浪面的实测波压分布不同于规范采用的均匀分布;规范计算得到的总水平力和波浪作用高度均小于实测值.本文改进规范中斜坡堤胸墙波浪力计算方法,使其更适用于深水堤顶部胸墙受力计算. 相似文献
7.
基于物理模型试验,考虑畸形波参数、相对板宽、相对波高等影响因素,就畸形波对平顶双层水平板防波堤作用进行研究。首先对畸形波作用下双层水平板的波浪力分布特征进行了讨论,然后就最大波动压强、结构最大总垂向力与不规则波作用进行了对比分析。结果表明,畸形波作用下,双层水平板最大波动压力出现在前端迎浪区域附近,向尾端逐渐递减。双层水平板4个受力面的压力分布不同且有相位差,4个受力面的最大波动压力时间差约在0.1Tp~0.4Tp范围内变化。与不规则波作用比较,畸形波作用没有显著改变波压包络分布特征,但增大了波压包络强度值。试验范围内,就最大总力而言,两者最大总浮托力比值在1.06~2.45间变化;向下的最大总垂向力比值在1.22~2.07之间变化;就波动压力而言,其增大的幅度与畸形波参数α1相关性最强,随α1的增大而增大,在α1=2.04~3.1试验范围内,畸形波作用时的最大压强比不规则波作用时可约增大20%~80%。就最大波吸力而言,两者的比值与畸形波参数α4相关性最强,随α4的增大而减小。在α4=0.62~0.75试验范围内,最大波吸力强度的比值在1.61~0.87范围内变化。当α4≤0.72时,畸形波作用时的最大波吸力大于不规则波作用时的最大波吸力;当α4 > 0.72时则刚好相反。 相似文献
8.
护面是海堤和护岸的重要结构,直接抵御波浪作用,可采用人工块体、块石等,种类繁多。采用紧密排列方块石作为护面结构是一种景观性较好的型式,依据方块石厚度不同能抵御不同大小的波浪作用。干砌条石及干砌块石护面曾有一些规范给出过计算方法,但现行规范没有相关内容可供设计参考,已有计算方法的理论分析还存在不足。当波浪与斜坡堤相互作用时,方块石护面出现位移或脱落可能发生在波浪回落最低阶段、波浪破碎打击阶段及破后爬高水流作用阶段,通过研究得到了不同阶段波浪对方块石护面作用力的计算方法。在波浪回落最低阶段,考虑了护面及其下方垫层渗透性影响,通过理论分析建立了低渗透护面浮托压强计算模型,采用物模试验将计算结果与试验测量值进行了对比分析,结果表明总体趋势符合,量值接近;在波浪破碎冲击阶段,基于射流冲击作用原理,提出了波浪在斜坡面破碎冲击压强计算方法,通过试验分析了波浪破碎水深波高比与破波相似参数的关系,利用浅水波理论计算了波浪破碎冲击水流流速;在爬高水流作用阶段,提出了水流引起的方块石护面垂直浮托力及水平拖曳力的计算方法,通过试验结果拟合了浮托力系数和拖曳力系数,验证了水流作用下护面的受力特征。最后,针对方块... 相似文献
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10.
本文通过实验,论述了高基床顶墙与波浪相互作用的机理,提出顶墙水平及垂直分布压强变化规律和新见解,本文结果已被农业部渔港斜坡式防波堤规范采用. 相似文献
11.
Numerical solutions have been obtained for the vertical uplift capacity of strip plate anchors embedded adjacent to sloping ground in fully cohesive soil under undrained condition. The analysis was performed using finite element lower bound limit analysis with second-order conic optimization technique. The effect of anchor edge distance from the crest of slope, angle and height of slope, normalized overburden pressure due to soil self-weight, and embedded depth of anchor on the uplift capacity has been examined. A nondimensional uplift factor defined as Fcγ owing to the combined contribution of soil cohesion (cu), and soil unit weight (γ) is used for expressing the uplift capacity. For an anchor buried near to a sloping ground, the ultimate uplift capacity is dependent on either pullout failure of anchor or overall slope failure. The magnitude of Fcγ has been found to increase with an increase in the normalized overburden pressure up to a certain maximum value, beyond which either the behavior of anchor transfers from shallow to deep anchor or overall slope failure occurs. 相似文献
12.
Li Yanbao Song Reng
Associate Professor Dept. of Hydralulic Eng. Tianjin University Tainjin .
Professor Dept. of Hydralulic Eng. Tianjin University Tainjin 《中国海洋工程》1996,(2)
The analysis of the data of model tests of two large deep wharves and monographic experimental studies show that two aspects are to be improved so as to predict the wave uplift forces on the bottom of a circular cylinder. The first aspect is the uplift pressure distribution on the bottom, and the second is the correct determination of the phase for maximum horizontal wave forces. The second problem has been solved. Synthesizing the results of theoretical analysis and experiments, we suggest a diagram for the determination of the phase when the maximum horizontal wave force appears. On the basis-ef the diagram the simultaneous wave uplift forces can be obtained for the structural stability analysis. 相似文献
13.
B. M. Das 《Marine Georesources & Geotechnology》2013,31(4):417-428
Laboratory model test results for the uplift of a shallow circular plate anchor embedded in a soft saturated clay are presented. For all tests the bottom of the anchor plate was vented to eliminate the mud suction force. The tests were divided into two categories: (1) short‐term tests to determine the variation of the net ultimate uplift capacity and hence the breakout factor with embedment ratio, and (2) creep tests with sustained uplift loads at varying embedment ratios. Based on the model test results, the variation with time, has been determined for the rate of strain of the soil located above the plate anchor. Empirical relationships for obtaining the rate of anchor uplift have been proposed. 相似文献
14.
Experimental Investigation of Irregular Wave Uplift Force on Deck of Exposed High-Pile Jetties 总被引：1，自引：0，他引：1
A laboratory setup was developed to investigate irregular wave uplift loads on exposed high-pile jetties.It is shown that the dimensionless uplift load increases to the maximum with an increasing relative clearance and then decreases.The relative clearance corresponding to the peak force is linked to a range from 0.4 to 0.8.When the relative clearance exceeds a certain value,the wave can not reach the underside of the deck and the force becomes zero.Distinct trends of dimensionless force with a relative width of deck show that the force tends to decrease as the relative deck width increases,and then the decrease slows down after the relative deck width increases or decreases to a certain value.The pressure distribution length associated with the maximum uplift force is equivalent to the wave contact width x.When x is larger than the width of deck B,it is taken as B.The statistical distribution of loads obeys the Weibull distribution.The results from the analyses of the real data suggest a new dimensionless prediction model on wave-in-deck uplift loads and the conversion ratio between wave loads at different exceedance probabilities.A comparison is made between the new prediction model and the existing widely used three prediction models.These results are used as useful references for structural design of the jetty. 相似文献
15.
Uplift Pressure of Waves on A Horizontal Plate 总被引：4，自引：0，他引：4
1 .IntroductionOwingtotheneedfordevelopingoffshoreresources,moreandmorehollow trussedstructuresareconstructed ,suchasalongshorequays ,islandquays,artificialislands ,bollards ,maritimeplatforms ,etc .Thelargeentitypartofthosemaritimestructuresusuallyconsistsofahorizontalplateabovethestillwaterlevel,anditusuallysuffersfromwaveattacksandthuscaneasilybedestroyed .Toavoidsuchakindofaccidents ,themostimportantistoaccuratelyevaluatetheupliftpressuresofwavesontheplateundervariouswaveconditionsandbound… 相似文献
16.
The wave transmission characteristics and wave induced pressures on twin plate breakwater are investigated experimentally in regular and random waves.A total of twenty pressure transducers are fixed on four surfaces of twin plate to measure the wave induced dynamic pressures.The spatial distribution of dynamic wave pressure is given along the surface of the twin plate.The uplift wave force obtained by integrating the hydrodynamic pressure along the structure is presented.Discussed are the influence of different incident wave parameters including the relative plate width B /L,relative wave height /i H a and relative submergence depth s /a on the non-dimensional dynamic wave pressures and total wave forces.From the investigation,it is found that the optimum transmission coefficient,t K occurs around B /L 0.41 ~ 0.43,and the twin plate breakwater is more effective in different water depths.The maximum of pressure ratio decreases from 1.8 to 1.1 when the relative submergence depth of top plate is increased from 0.8to +0.8. 相似文献