Shanghai is one of the areas severely affected by storm surge disasters. The seawall is the only barrier to protect Shanghai from storm surge disasters. Its defense capabilities are directly related to the safety of Shanghai's city. Limited by various factors, it will be difficult to comprehensively carry out large-scale heightening and reinforcement of the existing seawall in the future. Therefore, studying the defense capabilities of Shanghai's seawall structures and facilities, effectively improving the defense capabilities and controlling the damage caused by super typhoons within a reasonable range without large-scale engineering construction, is important to ensure Shanghai's social and economic security and sustainable development.
On the basis of collecting a large amount of hydrometeorological, terrain, seawall structure and other data, this project evaluates the defense level of the current seawall along the coast of Shanghai through a combined analysis of simulated wind, tide and wave analysis of the storm surges affecting Shanghai. Through the economic rationality analysis of different standards, we formulate seawall fortification standards, and propose countermeasures for possible typhoon and storm surges exceeding standard.
The key innovations of this project include: establishing a numerical model of storm surges and typhoon waves for Shanghai based on the statistical results of the wind speed frequency of a long series of typhoons along the coast of Shanghai; establishing typical standard typhoons, strong typhoons and super typhoons that Shanghai may encounter, and Based on this, relevant storm surge characteristic parameters were studied to provide basic parameters for assessment of seawall defense capabilities; This paper reveals the combined frequency level of Shanghai's current seawall frequency tide plus graded wind, and reveals the difference between the graded wind standard and the wind and tide frequency standard. Using the principle of optimal investment benefit combined with the operability of the fortification standard, a zoning fortification standard that reflects the essence of the same frequency of wind waves in the form of graded wind is proposed, and reveals the optimal economic fortification standard for Shanghai seawall.
The relevant research results of this project have been absorbed and adopted by the "Shanghai City Seawall Planning (2011-2020)" approved by the Shanghai City Government and the Shanghai City Engineering Construction Specification "Design Code for Shoal Sedimentation Promotion, Roundment and Land Reclamation Engineering DG/TJ08 -2111-2012."