摘要
本文从环境工程的角度讨论了岸滩侵蚀问题中建立分析模型的基本框架。讨论了岸滩岩土介质在风浪潮作用下 ,根据不同的侵蚀准则所建立的岸滩沉积物在近海迁移和传输的模型。得出了岸滩的侵蚀、演变过程由三相组成的结论 ,第一相是与饱和多孔介质经受动力载荷变形和损伤相联系的固态相 ;第二相是关于介质侵蚀和剥离的流 -固态混合相 ;第三相是流动和沉积物运输的流体相。从分析讨论还可以看出 ,岸滩侵蚀演化的模拟分析可在岸滩介质的动力固结、悬浮介质扩散漂移及海浪流体动力学理论相互交叉的基础上 ,针对海岸环境工程问题中的观念和现象来建模并完成。研究表明 ,在分析海滩侵蚀和海岸演化过程的机理时 ,采用海洋环境工程学中的相关方法可以得到更符合实际状况的结果。用损伤力学方法建摸研究岸滩介质的侵蚀和沙化过程 ,可以将海岸沉积物的迁移速率描述为海床面上的等效摩擦剪应力、损伤状态、侵蚀参数及介质的孔隙冲蚀率的函数。在岸滩侵蚀和演化机理研究中将海岸沉积物的纵向迁移和横向迁移理论相结合的模型有一定的优越性 。
This paper presents some environmental protection aspects on how to prevent the sea beach erosion so as to establish a basic modeling frame for analysis. The said modeling frame should be put on the basis of the interdisciplinary theories among the dynamic consolidation of the coastal medium, the diffusion and transportation of sediments and the fluid dynamics of the tided waves. For this purpose, different models of the sediment transition on the different erosion criteria of coastal medium under various actions of storm wave and tide have been analyzed and discussed. The process of beach erosion and coastal evolution can be considered to have three dynamic phases. The first phase is the solid phase, which is related to the deformation and damage of saturated porous medium under the dynamic actions. The second phase is the fluid solid interactive one, which deals with the erosion and the process of peeling off the coastal medium. The third phase is the fluid one, which consists of the water flow and sediment transition. The theory suggests that all the aspects and phenomena should be taken into comprehensive account in environmental engineering for simulating the process of the beach erosion and coastal line evolution. Taking some results present into consideration from the point of view of damage mechanics, the process modeling of the segregation of the coastal material from solid particles and sands down to very tiny sediments, the sediment transition rate can be expressed in a function of the equivalent fraction stress on the surface of the coastal line bed and the damage state or erosion parameters of coastal media as well as in equivalence with the porous evolution due to water drift through porous substances. An integrated model that combines the theory of cross shore and along the shore sediment transition thus can provide some advantages in presenting the mechanism of beach erosion and coastal evolution problem. Therefore, the above studies may help to develop a method for the quantitative analysis of the beach erosion and coastal line evolution.
出处
《安全与环境学报》
CAS
CSCD
2002年第3期8-12,共5页
Journal of Safety and Environment
基金
浙江省自然科学基金资助项目 (编号 :2 982 3)
