CN-121997583-A - Soft soil revetment design method considering wave influence

CN121997583ACN 121997583 ACN121997583 ACN 121997583ACN-121997583-A

Abstract

The invention discloses a soft soil shore protection design method considering wave influence, and belongs to the technical field of coastal engineering. The method comprises the steps of determining main factors influencing deformation and stress of a revetment structure by simulating tidal and wave propagation, analyzing wave elements and load data, simulating soft soil nonlinear characteristics and considering stress paths of a soil body under the action of wave load, building a revetment structure model by adopting finite element software and considering structural interaction, large deformation and contact problem factors, determining the influence of wave height and wave making moment on structural stress and deformation through data simulation, feeding back dynamic data of the environment where a revetment project is located into numerical simulation of the revetment structure, and continuously updating input parameters of the model to enable the model to dynamically reflect changes of actual project working conditions. The invention can accurately reflect the coupling effect of wave load and soft soil, improves the accuracy, safety and economy of revetment design, and is suitable for various soft soil foundation revetment projects.

Inventors

LI JIAHUA
DING PING
WANG DENGTING
CHEN LIANGZHI
HUANG ZHE
SUN TIANTING
WANG HAO
WU QIAO
SI JIALIN

Assignees

水利部交通运输部国家能源局南京水利科学研究院
中交第四航务工程勘察设计院有限公司

Dates

Publication Date: 20260508
Application Date: 20260121

Claims (8)

1. A soft soil shore protection design method considering wave influence is characterized by comprising the following steps: S1, simulating a wave propagation process based on tidal conditions and wave spectrum characteristics of a target sea area, acquiring wave elements such as wave height, period, wave direction and the like under different wave grade working conditions, and calculating corresponding wave load time course data; S2, simulating nonlinear mechanical behaviors of soft soil under the cyclic action of the wave load by adopting a soft soil constitutive model capable of reflecting a stress path effect, and determining equivalent soil mechanical parameters changing along with the wave level; S3, based on the wave load time course data and equivalent soil mechanical parameters, establishing a revetment structure-soft soil foundation coupling numerical model, wherein the model simultaneously considers structure-soil body contact nonlinearity, pore water pressure evolution and large deformation effect; s4, calculating through the coupling numerical model, obtaining stress response and deformation response of the revetment structure under different wave grade working conditions, and identifying wave control parameters with leading effect on structure safety based on preset deformation control indexes and stability criteria; And S5, triggering a model parameter updating mechanism when the wave control parameter or the structural response exceeds a preset threshold, feeding back updated wave load parameters and soil equivalent parameters to the coupling numerical model, and carrying out iterative optimization on the geometric parameters of the revetment structure through a multi-objective optimization algorithm to obtain a soft soil revetment design scheme meeting the stability, deformation control and engineering applicability.
2. The method for designing a soft soil revetment taking into account wave influence according to claim 1, wherein the step S1 comprises the sub-steps of: s1.1, firstly, simulating tidal change and wave propagation by using SWS wave software, and acquiring wave element data of different wave frequencies, wave heights and wave directions; S1.2, calculating wave load data, including hydrodynamic pressure and wave moment, and using the data as input parameters for analysis of a revetment structure model; S1.3, analyzing wave elements and load data, and determining wave height and wave moment which are main factors influencing deformation and stress of the revetment structure.
3. The soft soil revetment design method considering wave influence according to claim 1, wherein the improved soft soil constitutive model introducing wave cycle accumulation damage factors in the step S2 simulates soft soil nonlinearity, and introduces a parameter evolution mechanism changing along with the wave load cycle times and stress paths, so that shear strength parameters and compression parameters of soil bodies are dynamically adjusted along with the wave action process to characterize the accumulation influence of wave loads on soft soil mechanical properties, specifically, the nonlinear behavior of the soft soil shear strength along with effective stress increase and compression modulus along with the change of strain paths is simulated, the stress path effect under the wave load action is included in numerical simulation, the difference of the soil body mechanical behaviors under dynamic and static loading paths is contrasted and analyzed, the influence of different stress paths on soil body strength and deformation is clarified, and dynamic mechanical parameter support is provided for revetment soil interaction analysis.
4. The method for designing a soft soil revetment taking wave influence into consideration according to claim 1, wherein in step S3, the building of a revetment structure-soil body coupling numerical model specifically comprises the following sub-steps: S3.1, defining a contact interface between a revetment structure and a soft foundation by adopting a master-slave surface contact model, and setting a friction coefficient and cohesive force of the contact surface; S3.2, selecting a pore pressure unit for the soft soil foundation to couple and simulate the process of generation, diffusion and dissipation of excess pore water pressure caused by wave load; and S3.3, adopting any Lagrange-Euler method or self-adaptive grid technology to solve the problem of large deformation of the structure and soil caused by wave load.
5. The method for designing soft soil revetment considering wave influence according to claim 4, wherein in the master-slave surface contact model, the friction coefficient of the contact surface of the structure and the soil body is 0.2-0.4, and the cohesion is 20-30kPa.
6. The method for designing a soft soil revetment taking wave influence into consideration according to claim 1, wherein in the step S3, an ALE technique or an adaptive grid technique is adopted to solve the problem of large deformation of the revetment structure under the action of wave load.
7. The soft soil revetment design method considering wave influence according to claim 1, wherein the objective functions of the multi-objective optimization algorithm at least comprise maximum deformation of the revetment structure, key part stress utilization coefficient and structural material consumption, wherein the weight of each objective function is automatically adjusted according to the wave grade working condition, so as to realize cooperative optimization of the security and economy of the revetment structure under different wave action conditions.
8. The method for designing soft soil revetment taking wave influence into consideration according to claim 1, wherein the stress distribution, strain state and displacement response of the revetment structure under the wave action are obtained through finite element analysis, and the change relation of the maximum stress position and deformation quantity of the structure along with the wave height is determined.

Description

Soft soil revetment design method considering wave influence Technical Field The invention belongs to the field of coastal revetment engineering, and particularly relates to a soft soil revetment design method considering wave influence. Background Along with the rapid development of ocean economy and the development and utilization of coastal zone resources, the infrastructure construction of coastal areas is increased, and the revetment is taken as an important coast protection engineering form and is widely applied to projects such as ports, wharfs, river channels, coastal vacation areas and the like. However, soft foundations are commonly existed in coastal areas, and have low bearing capacity and large deformation, and the soft foundations pose a serious threat to the stability of the revetment structure. In addition, coastal areas are also often subjected to wave action, and the influence of wave loads on the stability of the revetment structure is not negligible. Therefore, the revetment structure on the soft soil foundation needs to be designed in consideration of wave influence to ensure the safety and reliability. Revetment engineering on soft foundations faces many challenges. Firstly, soft soil layers are generally thicker, can reach more than 20 meters, have the characteristics of high water content, low shear strength, high compressibility and the like, and cause the revetment foundation to be easy to subside and slide. Secondly, wave loads are complex in action, including horizontal impact forces, buoyancy, pulsating pressure and the like, and these loads are transmitted to the foundation through the facing blocks or breast walls, further exacerbating the deformation and strength weakening of the soft earth. Moreover, the wave crushing form is obviously influenced by the terrain condition, the waves are crushed in the middle of the revetment under the steep slope terrain, so that the horizontal force of the breast wall is increased, and the waves are crushed in the upper part under the gentle slope terrain, so that the increase of the surmounting amount and the block sliding can be caused. In addition, wave induced seafloor scour weakens the revetment base and may trigger an overall instability of the revetment when the scour depth exceeds 1/3 of the shore height or the width reaches 2-5 meters. The traditional revetment design method is mainly aimed at hard foundations, and is difficult to directly apply to soft foundations. In soft foundations, the bearing capacity and settlement deformation of the revetment structure are closely related to the properties of foundation soil, and wave loads can further affect the stability of the revetment. The traditional wave load calculation method is mainly based on a linear wave theory, and is difficult to accurately simulate the nonlinear characteristics of extreme waves, so that the design result is deviated from conservation or potential safety hazards exist. For example, experimental studies have shown that when there is a steep slope of terrain before shore protection, the experimental value of the breast wall horizontal force is much greater than the normal calculated value, while the buoyancy is closer to the normal value, which indicates that the traditional calculation method cannot accurately predict the effect of waves on shore protection in some cases. In addition, the existing method for calculating the wave force of the deep water breakwater (water depth is more than 20 m) and the breast wall under the shielding condition is imperfect in the design specification of breakwater and revetment (JTS 154-2018), and the difference between the current method and the actual measurement result of the object model test is 10% -30%, so that the current method needs to rely on the test or correction coefficient. The conventional soft soil foundation treatment technology has limitations in revetment engineering. The replacement filling method is suitable for soft soil with the thickness of not more than 4m, but has poor economical efficiency for deep soft soil foundations, the blasting and sludge discharging filling stone is suitable for silt and sludge soil with the thickness of 4-25 m, but has high construction risk, the composite foundation methods such as sand piles, gravel piles and the like can improve the bearing capacity of the foundation, but have high large-area treatment cost and long construction period, the chemical reinforcing methods such as cement stirring piles and the like have obvious reinforcing effects, but have generally higher manufacturing cost and adverse environmental protection, the dynamic consolidation methods such as dynamic compaction method, vibration compaction method and the like have limited treatment and influence depth on the foundation and are generally only suitable for reinforcing shallow layers, the pre-compaction drainage consolidation method of preloading and vacuum preloading is relatively effective, but has t