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1.
软基上的空心方块斜坡堤   总被引:6,自引:1,他引:5  
根据实际工程需要,提出了一种适宜建造在软土地基上的新的空心方块斜坡堤型式。这种新型结构是利用各空心方块之间以及空心方块本身的空隙,降低堤身单位体积的重量以及堤身断面总重量,从而满足软土地基承载力和整体稳定的要求:结合长江口深水航道治理工程的北导堤堤头部位2.6km长的软基段,对空心方块斜坡堤的设计和试验研究情况作概要介绍。  相似文献   

2.
不同结构离岸式潜堤消浪效果试验研究   总被引:1,自引:0,他引:1  
在某保滩促淤工程中,应用了离岸式潜堤技术。为了验证其不同结构形式的消浪效果,通过物理模型试验,对斜坡堤、大圆筒以及板桩直立堤的3种潜堤断面,在3种不同水位、波高作用下的消波效果作观测比较,并对其结果进行分析研究,旨在为工程设计和建设提供科学依据。  相似文献   

3.
通过整平船在长江口南导堤 Se段工程对流场影响的模型试验 ,得出各断面在不同潮位、流速、流向情况下 ,只有导堤和有整平船作业时会对周围流场有影响 ,为施工方案的比选以及施工中应采取的措施提供了可靠的依据。  相似文献   

4.
离岸潜堤在海滩养护中的作用   总被引:1,自引:0,他引:1  
本文以北戴河海滩养护试验工程为例,数值模拟了离岸潜堤的养滩促淤效应,通过物模试验研究了离岸潜堤对波浪的消减效果。探讨了潜堤透射系数和养滩功效。养滩工程监测数据又证实了用离岸潜堤进行养滩是合理的。同时,本文还对生态型离岸潜堤的应用提出了建议。  相似文献   

5.
天津古贝壳堤是天津海陆变迁的重要产物和有力佐证,具有重要的科学研究价值。通过对公路工程建设施工期施工振动、基础处理施工,营运期钻孔灌注桩承受垂直荷载、碎石垫层基础承受垂直荷载等因素对古贝壳堤保护区的影响分析,提出了保护古贝壳堤的对策和措施。  相似文献   

6.
为进一步了解栅栏板在海岸工程中使用情况,我们于今年五、六月份赴青岛、大连有关设计、施工和使用单位进行了现场参观学习和调查,并和这些单位有关工程技术人员进行了座谈讨论。栅栏板继在青岛交通部北海船厂防波堤后坡、海军某工程西防沙堤及东护岸投入使用后,又先后在大连石油七厂海坝接长工程、南护岸扩建工程及大连化工厂码头盐场扩  相似文献   

7.
基于1987年和1988年夏季在古镇口港直立堤前的实测资料,对波浪和波压力连续记录进行了统计分析和谱估计,研究了在堤前海浪不发生破碎条件下,堤前波浪和堤面不同高程上压力波的波面高度概率分布、堤前波浪波高和周期与波压力幅度和周期的概率分布特征、入射波行近提前过程中的谱变化及堤面不同高程上压力谱的变化特征。主要结果总结在本文最后一节。  相似文献   

8.
潜堤结构型式及其透射系数研究   总被引:6,自引:2,他引:6  
针对胜利油田某保滩促淤工程,进行了多种方案不同潜堤结构型式的优选,比较了其中四种结构型式,并对这四种结构型式的潜堤分别进行了波浪水槽试验,测试其透射系数,在此基础上,给出了计算潜堤透射系数的经验公式,为工程设计提供依据。  相似文献   

9.
姜梅 《海岸工程》2000,19(1):64-68
长久以来,人们采用各咎护岸工程保护遭受侵蚀的岸段,却忽视了由这些护岸建筑引起的负面效应--干坝、突堤、离岸堤可导致邻近岸段的蚀退;海提、护岸至少经岸下蚀;海滩的人工再塑难以解决沙源,一个护岸工程,不仅要在工程上可行,还应地周边环境产生负面影响,本文就此提出了几点建议。  相似文献   

10.
桩式离岸堤保滩促淤工程消浪效果试验研究   总被引:9,自引:0,他引:9  
在上海奉贤南北港保滩促淤工程中,采用了一种新型结构型式-桩式离岸堤,并通过物理模式试验进行了桩式离岸堤消浪效果研究。针对离岸堤通常建于近岸水区破波带的特点,重点研究水深,堤高以及堤身结构对波浪衰减的影响,同时对桩式离岸堤堤后水域的波浪底流速 分析探讨。研究结果表明,桩式离岸堤不仅具有良好的消浪效果。而且可在较大范围内改变波态,即由引起水体剧烈紊动的破波转变为浅水推进波,从而有效地改善海滩上的动力条件,促进海滩免受侵蚀,是一种具有广泛应用前景和新型保滩促淤结构。  相似文献   

11.
Articulated concrete block mattress revetment (ACB Mats) is an appropriate revetment for shore protection and breakwater. ACB Mats act as an integrated and flexible revetment against waves. There is a necessary need of investigation due to the lack of exact ACB Mat design relations in the estimation of hydrodynamic processes including wave run-up and run-down parameters. In the present study, using proper laboratory equipment, run-up and run-down processes were investigated under irregular waves and also granular and geotextile filters’ conditions. In this study, wave run-up and run-down estimation relations in ACB Mat revetment with the open area were explored for the first time. As the obtained results showed, relative maximum wave run-up and rundown are desirable for all conditions. Using a geotextile layer under ABC Mat caused a 14% increase in relative wave run-up values compared to granular filter. Further, in the run-down process, geotextile filter caused a 40% decrease in relative wave run-down values. The intensive decrease in run-down value occurred due to the outflow rate of the water from inside the filter with delay during water attack toward downward, which can be effective on structure stability significantly and should be considered in designs.  相似文献   

12.
海堤护岸是抵御和减轻风暴潮灾害的根本措施,是从根本上消除风暴潮对沿岸人民生命财产安全威胁的最有效措施之一。黄河三角洲沿海滩涂广阔平坦,多为沙质和淤泥质,沟壑交错,海堤护岸的建设量大面广,所以对区域内海堤护岸的建设方案进行比较优化,更显得十分必要。文章通过具体的工程案例,阐述了建于黄河三角洲滩涂区的海堤护岸结构方案的比选与优化步骤与方法,这无疑对建于滨海滩涂区的海堤护岸的方案优化具有直接的参考与借鉴意义。  相似文献   

13.
从海堤本身角度看,坝体过重与填料松散是影响其稳定性的主要因素,因此轻质硬壳堤坝是一种很好的选择。该结构采用高强度材料作为外壳,以松散材料填充坝体。根据受力特性、构造要求、施工条件及抗滑稳定条件拟解决结构断面设计的一些基本问题,并结合实例通过对比计算分析,说明轻质硬壳海堤比传统海堤具有更高的整体稳定性。  相似文献   

14.
不同结构形式潜堤上的随机波浪运动   总被引:3,自引:0,他引:3  
潜堤在海岸保护和促潍保淤中具有重要的意义。工程效益和经济投入受到潜堤结构形式和高度的影响。基于RANS方程和流体体积(VOF)方法的模型,计算不同潜堤上的波浪运动。潜堤形式包括矩形结构、梯形结构、半圆结构和槽形结构。模拟了不规则波越堤时波浪的破碎特征、破波类型以及波高的变化。通过分析流场和波高分布的变化,得到潜堤上波能散耗的规律,并且得出最优潜堤结构形式。讨论了相对堤顶高度、破碎点位置、相对堤顸宽度、波陡和潜堤结构形式等对波能耗散的影响。  相似文献   

15.
The Paraná Basin, southern Brazil, has an atypical thermal and fluid history due to the occurrence of an episodic continental flood volcanism during the Early Cretaceous. So far, there are few data about the influence of this volcanic event on the paleotemperatures and paleofluids of the Paraná Basin sedimentary rocks. The Teresina Formation in the northern flank of the Ponta Grossa dyke swarm hosts high concentration of subsurface igneous rock bodies (sills and dykes), besides its covering by a hundreds meter thick volcanic rock cap. In this study, we used fluid inclusion analysis performed in horizontal and vertical calcite veins from the Teresina Formation and from a Late Cretaceous basic dyke to estimate paleotemperatures and to characterize the composition of diagenetic paleofluids. Homogenization temperatures of requilibrated fluid inclusions show that the Teresina Formation reached temperatures above 200 °C. Horizontal parallel bedding calcite veins from the Teresina Formation record low to high salinity (2–26 wt.% NaCl eq.) aqueous paleofluids. The prevalence of high salinity fluid inclusions associated with light hydrocarbon fluid inclusions indicates deep buried fluids. Fluid inclusions in vertical calcite vein from basic dyke comprise only low salinity aqueous fluids (0–3 wt.% eq.NaCl) interpreted as dominated by meteoric water. The recorded paleotemperatures are attributed to the heating by the Paraná volcanic event during the Early Cretaceous, with the thermal effect of the volcanic rock cap surpassing the effect of nearby sills and dykes. Estimated paleotemperatures higher than 200 °C would allow the generation of light liquid and gaseous hydrocarbons. Overpressured compartments in the Teresina Formation allowed the expulsion of buried pore fluids (high salinity aqueous fluids and hydrocarbons) to fracture systems, where they mixed with meteoric water. The input of meteoric water through fracture systems connected with the surface favored hydrocarbons degradation in the early stages of source rock maturation during the Early Cretaceous.  相似文献   

16.
深层水泥搅拌法在土体加固中的应用   总被引:1,自引:0,他引:1  
介绍了在某护岸改造工程利用CDM加固体作为临时挡土墙的施工工艺。结果表明该工艺具有理想的效果,开创了CDM加固护岸坡脚土体的新工艺。  相似文献   

17.
我国硬式护岸、渔港工程和人工岛等3类典型海岸工程对相邻海滩有显著影响.本研究以泉州青山湾护岸、泉州崇武中心渔港、海口南海明珠人工岛等建设前后海滩变化为例,开展对海滩岸线形态及部分典型剖面形态的对比分析.结果表明,临海硬式护岸岸前海滩发生明显下蚀,护岸下游海滩岸线侵蚀后退,发育侵蚀热点,剖面伴有下蚀;渔港工程拦沙堤附近岸线局部淤涨,下游海滩岸线大范围侵蚀后退,出现侵蚀热点,侵蚀热点处剖面明显下蚀;人工岛后波影区内海滩淤积,形成沙岬或连岛沙坝突出体,突出体两侧岸线均发生不同程度侵蚀后退.通过分析典型工程案例,探讨了3类海岸工程对相邻海滩的影响方式、影响尺度和原因,对比分析不同类型海岸工程对相邻海滩的负面影响,可为海岸工程建设管理和海滩保护提供参考.  相似文献   

18.
以上海市向阳圩海塘围堰主堤为工程背景,在大量原位实测的基础上通过对各测试结果的统计分析研究了软土海滩围堰堤坝及地基沉降位移特性。结果表明:围堰堤坝及地基沉降具有显著的时效特性,沉降与时间的相关关系可用负指数时效特性曲线拟合;各测点位移值随时间具有明显突变变化,整个沉降时域可分为快速沉降时域区及缓慢沉降时域区。同时,在充分考察了沉降速率随时间变化特性的前提下提出了用该参量预测堤坝稳定时间及最终沉降位移的建议。  相似文献   

19.
为了能在各种不同地质的滩涂中发展水产养殖,快速、经济、高效地建造堤坝,提出了硬壳轻质堤坝在滩涂水产养殖中的应用结构体系。阐述了硬壳轻质堤坝的构造和材料、施工工艺及设计方法。具有施工快、稳定性好、防冲蚀、防渗性好的特点,从而提高软弱地基和砂土地基滩涂上的养殖效益。  相似文献   

20.
The Saemangeum Dyke is located in an estuarine setting, regulated in a complicated manner by a macrotidal regime, rivers, and winter monsoon. Accordingly, the constructed dyke resulted in a variety of artificial changes in geological characteristics in the estuary and its vicinity. To investigate those dyke-induced changes, the KORDI (Korea Ocean Research and Development Institute) performed sedimentological and sediment-dynamical observations from 2002 to 2010. On the basis of the KORDI results, the major geological changes and associated dynamical processes are reviewed. Five phenomena, among others, are focused on: depositional-channel creation; gap-related erosion; forced movements of surface sands; tidal-flat growth inside the dyke; and blanketing of mud over the sandy seafloor. These phenomena were unforeseen before the dyke construction, and reflect that the dyke could cause both erosion and deposition on an estuarine scale. The investigations conclude that the sediments in the dyke-influenced region were derived from the two rivers, Mangyeong and Dongjin, of the estuary. This is completely contrary to the offshore origin proposed before the dyke construction. As a result, the review supports the proposal that a thorough geological investigation and rational forecast is necessary prior to dyke construction to avoid economic loss and a fractious environmental debate.  相似文献   

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