水工工程CDM体的陆上施工

以青岛某水工工程为例,介绍了在海中施工CDM桩护岸的主要施工技术和施工方法。工程采用了CDM桩的海中支架设计,介绍了CDM桩块体机具选择,CDM桩配合比设计及最终CDM块体的成桩咬合布置、水下CDM成桩主要施工技术参数和工艺。为以后类似CDM桩施工提供借签。     

黄河三角洲海岸防护工程研究

黄河三角洲海岸带的护岸工程,主要经历了３个发展阶段：１９８３年以前为初期护岸阶段,仅在局部地区护岸且基本为土堤护岸;１９８３－１９９２年,护岸工程大发展阶段,且进行了大范围石堤护岸;１９９２年以后至今,护岸工程的维护和持续发展阶段。随着护岸工程的不断修建,护岸工艺和技术有很大发展。     

护岸工程与沙滩流失

沙滩是沿海地区重要的旅游休闲资源,护岸工程是沿海地区重要的防灾设施,护岸在保护陆地资源的同时有可能对沙滩产生破坏。传统护岸设计形式为硬性护岸,硬性护岸建成后将在一定程度上影响沿岸水动力环境,若护岸设计不当,易引起周围沙滩流失,造成旅游经济损失。本文通过威海九龙湾沙滩流失实例说明了硬性护岸对沙滩稳定性的影响,并通过波浪泥沙物理模型试验对沙滩修复方案进行了研究,试验发现因受原护岸影响修复后的沙滩仍将处于持续侵蚀状态,并介绍了其他类似案例。文中重点强调了护岸设计不当极易造成沙滩流失,对护岸设计、岸线规划等具有一定参考价值。     

国外保护海岸带的几种方法

本文简述了海岸带破坏的原因、目前国外保护海岸带的方法和技术。目前国外采用丁坝、护岸墙、防波堤、沿岸保护堤、人工回填海岸和修建人工海滩、抛堆石块和用特殊塑料袋建造护岸设施的方法保护海岸带。其中丁坝和防波堤是最常用的方法,用泥砂回填海岸和建造人工海滩是目前比较先进的护岸方法,利用塑料编织袋修建护岸设施具有廉价而快速的特点。此外,还简述了护岸的方法、原理和注意事项以及护岸原则。     

护岸工程设计的体会和实例

通过青岛海洋公园、名人精品雕塑园等护岸工程设计实例,总结介绍了护岸工程设计体会,包括平面布置原则,高程确定方法,护岸结构型式等。     

黄河口附近护岸工程的风险分析

护岸工程在建造和运营中 ,经常会遇到各种风险。为了保护胜利油田陆上的油气开发设施 ,应用风险分析技术对黄河口附近护岸 (海堤 )工程的风险进行了探讨 ,并提出了该海区护岸工程防范风险的对策     

岛屿地形下的核电厂护岸防洪设计研究

对国内第一个岛屿地形下核电厂的护岸防洪设计进行了研究,提出直立式护岸结构方案以满足核电厂防洪和避让毗邻海岛的要求。在波浪数值模拟计算结果基础上,开展了波浪整体物理模型试验、波浪局部整体物理模型试验和波浪断面物理模型试验,对护岸的越浪量和结构稳定性进行了优化验证。研究结果表明,岛屿地形下,波浪破碎和波能集中导致护岸堤身坡脚处波高增大,须加高挡浪墙和优化挡浪墙结构型式;在相同的越浪量标准下,采用直立堤结构相对斜坡堤结构对应的护岸挡浪墙的高程须明显加高;利用部分海岛地形斜坡高地作为厂区护岸一部分时,原状海岛地形斜坡高地处的波浪爬高效应明显,须加高邻近护岸挡浪墙的高程。     

黄河三角洲滩涂区海堤护岸结构方案优化实证研究

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。     

略论护岸工程的负面影响：以美国护岸工程为例

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。     

钱塘江涌潮区护岸工程的设计及研究

丁坝在江道整治及护岸工程中已有比较广泛的应用。丁坝的平面布置、结构型式与丁坝自身的稳定性及护岸效果密切相关。本文在对钱塘江涌潮区护岸丁坝的设计作了初步总结的基础上,指出了在丁坝结构上存在的一些问题,提出了相应的改进方案,并结合抢险修复工程,进行了现场原型试验。试验结果表明,本文提出的改进方案是切实可行的。     

Assessment of Unconfined Compressive Strength of Cement Stabilized Marine Clay

Two aspects of deep mixing method, the difference relating strength gain in dry jet mixing (DJM, reagent powder introduced into the ground) and cement deep mixing (CDM, reagent slurry introduced into the ground), and prediction of unconfined compressive strength of cement stabilized marine clay, are discussed in this paper. The first part of this paper concentrates on the difference between DJM and CDM on strength gain, and suggests a guideline for DJM and CDM selection. An indicator in terms of water content ratio, which is defined as the ratio of water content to the liquid limit of the soil, is presented by statistical analysis from the laboratory and field test data as a guideline for the selection of DJM or CDM. Based on the laboratory test data, a mathematical model relating strength gain of cement stabilized marine clay to related variables is developed. A new simple index designated as total water-cement ratio, which is defined as the ratio of water weight in the soil-cement to the weight of cement in dry state, is proposed for interpretation of test data of soil-cement. The proposed method is then verified with available test data published by other different researchers.     

Assessment of Unconfined Compressive Strength of Cement Stabilized Marine Clay

Two aspects of deep mixing method, the difference relating strength gain in dry jet mixing (DJM, reagent powder introduced into the ground) and cement deep mixing (CDM, reagent slurry introduced into the ground), and prediction of unconfined compressive strength of cement stabilized marine clay, are discussed in this paper. The first part of this paper concentrates on the difference between DJM and CDM on strength gain, and suggests a guideline for DJM and CDM selection. An indicator in terms of water content ratio, which is defined as the ratio of water content to the liquid limit of the soil, is presented by statistical analysis from the laboratory and field test data as a guideline for the selection of DJM or CDM. Based on the laboratory test data, a mathematical model relating strength gain of cement stabilized marine clay to related variables is developed. A new simple index designated as total water-cement ratio, which is defined as the ratio of water weight in the soil-cement to the weight of cement in dry state, is proposed for interpretation of test data of soil-cement. The proposed method is then verified with available test data published by other different researchers.     

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的影响研究

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.     

Wave run-up and rundown on ACB Mats under granular and geotextile filters’ condition

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.     

轻型连续沉井在护岸工程中的应用

结合青岛浮山湾北海船厂西护岸工程，对轻型连续沉井在护岸工程中的应用作了系统介绍。连续沉井在该工程的软基上作为干插条石斜坡堤的堤脚支撑并兼有护底防冲刷以及消浪功能，具有施工方便，造价经济，美观实用等优点，有一定的推广使用价值．对该类轻型沉井的设计和施工作了较为详细的阐述，便于工程应用。     

Static stability of submerged partial revetment structures under regular and irregular waves

Physical models of submerged partial revetment structures were built on natural beach sand with a diameter of 0.35 mm and specific gravity of 2.63. The armor units, the diameter and specific gravity of which varied in the range of 8.5–67.95 mm and 1.81–2.77 respectively, were placed only on wave breaking areas. A series of experiments has been conducted on the conditions of different armor units and different wave characteristics using regular waves and irregular waves. Based on the experimental data, the effects of wave height, wave period, diameter and specific gravity of armor units, water depth in the channel, and wave types on static damage of given structures are assessed. Some empirical formulas have been suggested through regression analysis to describe static stability and stability number of submerged partial revetment structures under pure regular waves, pure irregular waves, and regular–irregular waves. The suggested formulas compared with Van der Meer’s (1988) formulas and some differences have occurred because of differences among revetment types and test conditions; therefore, proposed formulas give reasonable results for the test conditions used.     

Rapid erosion of a small southern California beach fill

A winter storm eroded a small (160,000 m³) beach fill at Torrey Pines State Beach in southern California. The fill, constructed in April 2001, was a 600-m long flat-topped berm, extending from a highway revetment seaward about 80 m, terminating in a 2-m tall, near-vertical scarp. The size distributions of the preexisting and fill beach sand were similar (median ∼0.2 mm). A total of 56 cross-shore transects were surveyed between the revetment and 8 m water depth biweekly along 2.7 km of the beach centered on the fill area. During summer and fall, the incident significant wave heights measured 1 km offshore of the fill usually were below 1 m, the scarp was not overtopped, and the fill did not change greatly. The beach face alongshore of the fill accreted, consistent with the usual seasonal cycle in southern California. During a storm (3 m significant wave height) in late November, erosion began when wave uprushes overtopped the scarp and reached the relatively flat elevated fill, where the overwash flowed alongshore to initially small depressions that channeled the flow seawards. The offshore flow rapidly deepened and widened the channels, which maintained steep vertical faces and eroded by slumping. Thirty hours after the storm began, the shoreward end of the eroded channels had retreated to the highway revetment, leaving uneroded sand peninsulas protruding seawards ∼50 m from the revetment and elevated ∼1.75 m above the surrounding beach. Erosion of the beach adjacent to the fill was much less variable alongshore than within the fill region. During the next few days, the peninsulas eroded almost completely.