A method for evaluating wave impact force on rock cliff with straight wall

Abstract

The present application provides a kind of wave to straight wall type rock slope impact force evaluation method, comprising the following steps: S1 according to the main form of straight wall type rock slope, constructs numerical model;S2 according to actual marine environment, sets boundary condition to numerical model;S3 selects the numerical calculation method suitable for wave and rock slope interaction, sets numerical simulation program;S4 runs numerical simulation program to simulate the stress-strain response of rock slope under wave action;S5 combines specification calculation result to analyze numerical simulation result;S6 according to actual working condition, evaluates the impact force of wave to straight wall type rock slope.The present application can use numerical simulation method to simulate and calculate the impact force of wave to straight wall type rock slope, and according to specification calculation result and actual working condition, evaluates the impact force of wave to straight wall type rock slope, provides a more standardized, effective and intuitive evaluation method to evaluate the influence of wave on rock slope stability and govern rock slope, to guide actual marine engineering construction work.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of marine engineering geology, and particularly relates to a method for evaluating wave impact force on a straight-wall rock slope. BACKGROUND

[0002] With the rapid development of the national economy and society, the exploration and construction scale of marine resources are expanding, and gradually developing from the shallow sea to the deep sea. In the process of engineering construction and operation, the evaluation of possible geological disasters in the surrounding marine environment is essential, and the geological disasters caused by wave impact leading to the instability of the rock slope around the marine engineering need to be highly valued.

[0003] One of the causes of the hydrodynamic triggering mechanism of marine geological disasters is wave, which is generated by marine climate natural factors such as storms. In its travel process, it will continuously exert normal stress and shear stress on the marine slope, affecting the stability of the rock slope, and ultimately leading to the destruction of the internal structure of the slope and landslides. The influence of wave impact on the stability of the rock slope mainly includes two points: first, the cyclic impact of waves on the slope surface of the rock slope, under the action, transient pore water pressure and residual pore water pressure are generated in the internal structure of the rock, and the internal stress changes significantly due to the accumulation of internal excess pore water pressure; second, the weakening effect of waves on the structural surface, which is reflected in the long-term and repeated action of waves on the rock mass and its structural surface, and the physical and chemical properties of the rock mass change under the influence of long-term cyclic stress, reducing the strength and deformation modulus of the rock. Waves mainly affect the internal structure of the rock slope, which is not easy to observe and once damaged, the damage is extremely great, which seriously threatens the life and property safety of the marine engineering and staff related to the slope.

[0004] However, the current research object of the slope stability analysis under the influence of waves mainly focuses on soil slopes, although a series of standard calculation analysis and model test research results have been achieved in this regard, but there are relatively few evaluation contents of wave impact force on rock slopes, and there is also a lack of comparison research on standard calculation results and numerical simulation results. The evaluation of wave impact force on straight-wall rock slopes needs a more standardized and effective evaluation method to guide the actual marine engineering construction work. SUMMARY

[0005] In view of the deficiencies in the prior art, the present application provides a method for evaluating wave impact force on a straight-wall rock slope, which uses standard calculation method and numerical simulation method to calculate and analyze the wave action on the rock slope, and finally carries out comparison analysis to select the calculation results, so as to effectively and quickly determine the wave impact force on the straight-wall rock slope.

[0006] The technical scheme adopted by the present application is a method for evaluating the impact force of waves on a straight-wall rock slope, which accurately evaluates the impact force of waves on a rock slope by combining a three-dimensional numerical model with specification calculation, and comprises the following steps:

[0007] Step S1: According to the geometric shape, structural characteristics and geological composition of the straight-wall rock slope, a three-dimensional numerical model is constructed to simulate the geometric shape and physical properties of the slope structure.

[0008] Step S2: According to the actual marine environmental conditions and wave characteristics, the boundary conditions of the numerical model are set, including wave parameters, slope material properties and surrounding environmental factors.

[0009] Step S3: Select a numerical calculation method suitable for the interaction of waves and rock slopes, set the calculation method and parameters of the numerical simulation program, including the numerical method used, the time step.

[0010] Step S4: Run the numerical simulation program to simulate the stress-strain response of the rock slope under the action of waves, and obtain the pore water pressure and stress distribution data.

[0011] Step S5: Combine the specification calculation results, analyze the numerical simulation results, compare and verify the accuracy of the numerical simulation results, and adjust the model parameters to optimize the results.

[0012] Step S6: According to the simulation results and actual working conditions, the impact force of waves on the straight-wall rock slope is evaluated, and specific suggestions are provided for engineering design and safety protection.

[0013] Preferably, in step S1, the method for constructing a three-dimensional numerical model comprises using a numerical simulation software (such as Flow-3D program, MIKE 21 program and SWAN program, etc.) to establish a 1:1 reduction numerical model of wave propagation and straight-wall rock slope according to the main shape of the straight-wall rock slope, considering the actual conditions, and inputting the characteristics of the waves, the geometric shape of the straight-wall rock slope and the material property parameters.

[0014] Preferably, in step S2, the boundary conditions of the numerical model include important numerical simulation setting options such as wave source input, water depth distribution, geometric shape of the straight-wall rock slope, and bottom friction coefficient.

[0015] Preferably, in step S3, the setting of the calculation method and parameters is selected according to the specification and formula, and the impact force of the waves on the model is calculated in combination with the wave parameters and the geometric shape of the model.

[0016] Preferably, in step S3, the formula selected for the calculation method is the impact force calculation part based on the specification "Hydrological Specification for Sea Port" (JTS145-2-2013), which is calculated according to the following steps:

[0017] determining the wave state of the wave acting on the straight wall rock slope;

[0018] calculating the impact force of the straight wall rock slope under the action of wave crest and wave trough.

[0019] Preferably, in step S3, the wave state of the wave acting on the straight wall rock slope is determined according to the conditions of the slope and the wave, and the generation condition of the standing wave should satisfy that the wave crest line is approximately parallel to the slope, and the length of the slope is greater than one wavelength, and also needs to satisfy the following formula:

[0020]

[0021]

[0022] In the formula: - average period of wave (s); d - water depth in front of the slope (m); H - wave height at the place where the slope is located (m); g - acceleration of gravity (m / s 2 ).

[0023] Preferably, the impact force of the straight wall rock slope under the action of wave crest and wave trough includes selecting corresponding formula to calculate according to the characteristics of the slope and the wave:

[0024] When d≥1.8H and d / L=0.05-0.12 (L is the wavelength), the impact force under the action of wave crest can be calculated according to the wave pressure distribution diagram of the impact wave under the action of wave crest in the specification "Hydrological Specification for Sea Port" (JTS145-2-2013) according to the following provisions:

[0025] ① The wave surface elevation is calculated according to the following formula:

[0026]

[0027]

[0028]

[0029]

[0030] In the formula: η c - wave surface elevation (m); d - water depth in front of the slope (m); B η , m - correction coefficient; T * - dimensionless period (s); - average period (s); g - acceleration of gravity (m / s 2 );

[0031] ② h cThe wave pressure intensity on the slope surface is calculated by formula (7) ～ (9) Calculation:

[0032]

[0033] n = [0.636618 + 4.23264(H / d) 1.67 , 1.0] (9)

[0034] In the formula, h c — Wave pressure intensity p ac The position of the action point above the calm water surface (m); p ac — Corresponding to h c The wave pressure intensity on the slope surface (kPa); n — The exponent of the wave pressure intensity distribution curve above the calm water surface, which takes the larger value of the two numbers in the formula; p oc — The wave pressure intensity on the calm water surface (kPa); γ — The specific weight of water (kN / m 3 );

[0035] ③ The wave pressure intensity p oc on the calm water surface and the wave pressure intensity on the slope surface at other characteristic points are calculated by formula (10) when p bc > p oc , p bc = p oc , where p bc is the wave pressure intensity on the slope surface corresponding to the water depth of d / 2 (kPa):

[0036]

[0037] In the formula, p — The wave pressure intensity on the slope surface at each characteristic point (kPa); A p , B p , q — The wave peak action coefficient, which is determined according to the corresponding parameter table;

[0038] ④ The total horizontal wave force P c (kN / m) per unit length of the shore slope is calculated by formula (11):

[0039]

[0040] In the formula, P c — The total horizontal wave force (kN / m) per unit length of the shore slope; pd c — The wave pressure intensity at the slope bottom (kPa); pb c — The wave pressure intensity on the slope surface corresponding to the water depth of d / 2 (kPa);

[0041] ⑤ The total horizontal wave moment M c (kN·m / m) per unit length of the shore slope is calculated by formula (12):

[0042]

[0043] wherein M c — the total horizontal wave force moment per unit length of the slope (kN·m / m);

[0044] ⑥ The wave uplift force P on the slope bottom surface per unit length is calculated according to formula (13): uc

[0045]

[0046] wherein P uc — the wave uplift force on the slope bottom surface per unit length (kN / m); B — the width of the slope bottom (m);

[0047] d≥1.8H and d / L=0.05 ～ When d / L=0.12, the impact force under the action of wave trough can be calculated according to the wave trough impact wave pressure distribution diagram in the Code for Hydrology of Sea Port (JTS145-2-2013) according to the following provisions:

[0048] ① The wave trough surface elevation η t is calculated according to formula (14):

[0049]

[0050] wherein η t — the wave trough surface elevation (m); A p , B p , q — the wave trough action coefficient, which can be determined according to the parameter table in the Code for Hydrology of Sea Port (JTS145-2-2013);

[0051] ② The wave pressure intensity p on each feature point on the slope surface is calculated according to (15), wherein the coefficients A p , B p , q are determined according to the corresponding parameter table, and when p dt > p ot , p dt = p ot , wherein p dt is the wave pressure intensity at the slope bottom (kPa); p ot is the wave pressure intensity corresponding to the wave trough surface (kPa):

[0052] p = A p + B p (H / d) q (15)

[0053] wherein p — the wave pressure intensity on each feature point on the slope surface (kPa);​

[0054] ③ the total horizontal wave force on the slope per unit length P t According to formula (16):

[0055]

[0056] P = pB t — the total horizontal wave force on the slope per unit length (kN / m); p dt — the wave pressure intensity at the slope bottom (kPa); p ot — the wave pressure intensity corresponding to the wave trough surface (kPa);

[0057] ④ the downward wave force on the slope bottom surface per unit length P ut According to formula (17):

[0058]

[0059] P = pB ut — the downward wave force on the slope bottom surface per unit length (kN / m); p dt — the wave pressure intensity at the slope bottom (kPa); B — the slope bottom width (m);

[0060] d≥1.8H, 0.12≤d / L<0.139 and 8<T * ≤9, the wave pressure intensity and the wave surface elevation and other values can be calculated according to the following formulas (18) and (19):

[0061]

[0062]

[0063] T = 8 * — the dimensionless period of actual wave condition; X T* — represents the wave pressure intensity and the wave surface elevation and other values; — T * = 8 and the H / d value of actual wave condition; — T * = 9 and the H / d value of actual wave condition.

[0064] Preferably, in step S4, the operation of the numerical simulation program comprises:

[0065] using the numerical simulation program to simulate the propagation, reflection, refraction and interference of waves around the breakwater;

[0066] using the numerical simulation program to calculate the wave height, wave pressure, wave velocity parameters and the interaction between the wave and the straight wall type rock slope, and finally to obtain the specific impact force result.

[0067] Preferably, in step S5, the analysis of the numerical simulation result comprises comparing the difference between the standard calculation result and the numerical simulation calculation result, specifically by calculating the impact force result under different working conditions, and analyzing the difference between the impact force results calculated by the two methods, so as to further develop the analysis.

[0068] Preferably, in step S6, the evaluation of the impact force of the wave on the straight wall type rock slope comprises evaluating and analyzing the calculation result of the wave impact force in combination with the actual working condition and the need of the marine engineering construction, and taking the result as a reference basis for the actual engineering construction.

[0069] From the above technical solution, the beneficial technical effects of the present application are as follows:

[0070] In the method, a high-precision numerical model is established to carry out numerical simulation calculation on specific examples, the results under different working conditions are compared with the results of corresponding standard calculation, so as to ensure the accuracy and rationality of the evaluation result, and the impact force of the wave on the straight wall type rock slope can be more normatively and effectively evaluated, the water pressure cloud chart derived by the numerical simulation program can more intuitively analyze the impact of the impact force, and at the same time, a reference basis is provided for the local marine engineering construction. BRIEF DESCRIPTION OF DRAWINGS

[0071] Figure 1 is the calculation flowchart of the wave impact force evaluation method of the straight wall type rock slope according to the embodiment of the present application;

[0072] Figure 2 is the impact wave pressure distribution graph when the wave peak acts, and the relationship between the water depth and the wave height and the wave length is d≥1.8H and d / L=0.05-0.12 according to the embodiment of the present application;

[0073] Figure 3 is the impact wave pressure distribution graph when the wave valley acts, and the relationship between the water depth and the wave height and the wave length is d≥1.8H and d / L=0.05-0.12 according to the embodiment of the present application;

[0074] Figure 4 is the water pressure schematic cloud chart at the time of 36 seconds in the numerical simulation according to the embodiment of the present application;

[0075] Figure 5 is the condition and calculation result comparison graph of working conditions 1-5 according to the embodiment of the present application;

[0076] Figure 6 is the water pressure calculation result comparison distribution graph according to the embodiment of the present application. DETAILED DESCRIPTION

[0077] In order to make the purpose, technical scheme and advantages of the present application more clear, the embodiments of the present application will be further described below with reference to the drawings.

[0078] The embodiment takes a straight wall type rock slope in the southeast coastal area of China as the evaluation research object. Please refer to Figure 1 The embodiment of the present application provides a method for evaluating the impact force of waves on a straight wall type rock slope, comprising the following steps:

[0079] Step 1: Construct a numerical model according to the main form of the straight wall type rock slope.

[0080] The numerical simulation program uses Flow-3D software. In the program, a physical model is selected, and a calculation model of the straight wall type rock slope is constructed according to the characteristic parameters of the waves (such as wave height, wavelength, etc.), the geometric shape of the model, and the material properties, etc. The numerical simulation model is specifically set as follows:

[0081] (1) Size and structure. In order to make the time period and spatial period of reading data stable, and also to make the distance between the boundary and the structure far enough, so that the waves move in the Y direction in a natural way, the length of the wave tank is taken as 200m, and the rock slope is placed in the rear position. Such a distance will not affect the wave state. The height of the tank is taken as 10m, which ensures that the activity range of the waves is completely contained in the calculation grid area. The structure is a straight wall, the height is taken as 25m, and the bottom width is taken as 10m.

[0082] (2) Physical model setting. In the simulation of the embodiment, the fluid is set as a free surface flow, an incompressible flow; the fluid quantity is a single fluid; the physical model is selected as gravity and non-inertial reference system, viscosity and turbulence model.

[0083] (3) Fluid parameter setting. In this simulation, the fluid is set as a viscous fluid, the turbulence model is set as a k-e two-equation model, the maximum turbulence mixing length is dynamically calculated, the wall shear boundary condition is set as a no-slip condition, and the friction coefficient is set as -1. At the same time, the water temperature is set as 20℃.

[0084] (4) Grid division. In this simulation, a three-dimensional grid is set, in which the X axis coordinate is 0 to 200m, the Y axis coordinate is 0 to 1m, and the Z axis coordinate is 0 to 25m, a total of 125000 grids are set. In order to simulate the boundary conditions of the waves, the X min boundary condition is set as a wave boundary, and the water surface elevation is set as 10m. The Z max boundary condition is set as a specified pressure condition, in which the fluid fraction is set as 0, indicating the air interface. Through such setting, the interaction between the waves and the fluid can be more accurately simulated.

[0085] Step 2: Set the boundary conditions for the numerical model according to the actual conditions.

[0086] The boundary condition setting of the numerical model needs to make the selection of the boundary type suitable for the selected boundary and set the properties related to the boundary type.

[0087] (1) X direction

[0088] The simulated X min The boundary type of the boundary is set to the wave boundary, described by the Stokes wave and the Cnoidal wave. The fluid height is set to 10 m, the X max The boundary condition is the wall boundary.

[0089] (2) Y direction

[0090] Y min The boundary is set to the symmetry (Symmetry) boundary, which can avoid the error of wave reflection when the wave is obliquely incident to the shore slope during simulation. Moreover, the symmetry boundary can very well simulate the problem with the symmetry flow characteristics of the actual flow, reduce the calculation workload, and utilize the symmetry to not only reduce the storage space but also preserve the complete calculation results.

[0091] (3) Z direction

[0092] Z max The boundary condition is the specified pressure boundary, and the fluid fraction is 0, that is, the air interface. This can reduce the friction of the bottom boundary of the numerical model, prevent the large attenuation of the wave height, make the wave height at the structure approximately the same as that at the incident position, and ensure that the simulation is more consistent with the actual wave.

[0093] Step 3: Set the calculation method of the numerical simulation program.

[0094] In order to ensure that the calculation results of the numerical simulation program are more referential, at the same time, the standard calculation is carried out for comparison, for the convenience of calculation, the calculation formula is input into the Matlab program for auxiliary calculation. The calculation formula of the numerical simulation and the standard calculation is based on the impact force calculation part of the standard “Harbor Hydrology Specification” (JTS145-2-2013), and the calculation is carried out according to the following steps:

[0095] Determine the wave state of the wave acting on the straight wall rock slope;

[0096] Calculate the impact force of the straight wall rock slope under the action of the wave crest and the wave trough.

[0097] (1) The wave state of the wave acting on the straight wall rock slope is determined according to the slope and wave conditions. The generation condition of the standing wave should satisfy that the wave crest line is approximately parallel to the slope, and the length of the slope is greater than one wavelength, and at the same time, the following formula needs to be satisfied:

[0098]

[0099]

[0100] wherein: - average wave period (s); d - water depth in front of the bank slope (m); H - wave height at the bank slope (m); g - gravitational acceleration (m / s 2 ).

[0101] (2) The impact force of a straight wall rock bank under the action of wave crest and wave trough is calculated according to the characteristics of the bank and the wave, and corresponding formulas are selected for calculation:

[0102] See Figure 2 , when d≥1.8H and d / L=0.05-0.12 (L is the wave length), the impact force under the action of the wave crest can be calculated according to the impact wave pressure distribution diagram under the action of the wave crest according to the following provisions:

[0103] ① The wave surface elevation is calculated according to the following formula

[0104]

[0105]

[0106]

[0107]

[0108] wherein: η c - wave surface elevation (m); d - water depth in front of the bank slope (m); B η , m - correction coefficient; T * - dimensionless period (s); - average period (s); g - gravitational acceleration (m / s 2 ).

[0109] ② The slope wave pressure intensity at h c above the static water surface is calculated according to formula (7) ～ (9)

[0110]

[0111]

[0112] n = [0.636618 + 4.23264 (Hld) 1.67 , 1.0] (9)

[0113] wherein: h c - wave pressure intensity p ac at the action point position above the static water surface (m); p ac - hc corresponding to the water depth d / 2 (kPa); n —— exponent of the wave pressure intensity distribution curve above the calm water surface, whose value is the larger one of the two numbers in the formula oc wave pressure intensity above the calm water surface (kPa); γ —— specific weight of water (kN / m 3 ).

[0114] ③ wave pressure intensity p oc above the calm water surface and the wave pressure intensity at other characteristic points on the slope are calculated by formula (10) when p bc >p oc , p bc = p oc , and when p bc <p p , p p = p c , where p c is the wave pressure intensity on the slope corresponding to the water depth d / 2 (kPa);

[0115]

[0116] In the formula: p —— wave pressure intensity at each characteristic point on the slope (kPa); A p , B p , q —— wave crest action coefficient, determined according to the corresponding parameter table.

[0117] ④ total horizontal wave force P c (kN / m) per unit length of the shore slope is calculated by formula (11);

[0118]

[0119] In the formula: P c — total horizontal wave force (kN / m) per unit length of the shore slope; p dc — wave pressure intensity at the slope bottom (kPa); p bc — wave pressure intensity on the slope corresponding to the water depth d / 2 (kPa).

[0120] ⑤ total horizontal wave moment M c (kN·m / m) per unit length of the shore slope is calculated by formula (12);

[0121]

[0122] In the formula: M c — total horizontal wave moment (kN·m / m) per unit length of the shore slope.

[0123] ⑥ wave uplift force P uc (kN / m) per unit length of the slope bottom surface is calculated by formula (13).

[0124]

[0125] In the formula: Puc Wave uplift force on unit length of slope bottom surface (kN / m); B - width of slope bottom (m).

[0126] See Figure 3 When d≥1.8H and d / L=0.05-0.12, the impact force under the action of wave trough can be calculated according to the wave pressure distribution diagram of the impact wave when the wave trough acts, as follows:

[0127] ① Wave trough wave surface elevation η t Calculated according to formula (14):

[0128]

[0129] In the formula: η t - Wave trough wave surface elevation (m); A p , B p , q - Wave trough action coefficient, which can be determined according to the parameter table of the specification "Hydrological Specification for Sea Port" (JTS145-2-2013).

[0130] ② The wave pressure intensity p of each feature point on the slope surface is calculated according to (15), and the coefficients Ap, Bp, q are determined according to the corresponding parameter table. When p dt > p ot , take p dt = p ot , where p dt is the wave pressure intensity at the slope bottom (kPa); p ot is the wave pressure intensity corresponding to the wave trough wave surface (kPa);

[0131] p = A p + B p (H / d) q (15)

[0132] In the formula: p - Wave pressure intensity of each feature point on the slope surface (kPa).

[0133] ③ The horizontal total wave force P t on unit length of slope body is calculated according to formula (16);

[0134]

[0135] In the formula: P t - Horizontal total wave force on unit length of slope body (kN / m); pd t - Wave pressure intensity at the slope bottom (kPa); po t - Wave pressure intensity corresponding to the wave trough wave surface (kPa).

[0136] ④ The downward wave force P utCalculate according to formula (17).

[0137]

[0138] In the formula: P ut —The downward wave force per unit length on the bottom surface of the slope (kN / m); p dt — Wave pressure intensity at the bottom of the slope (kPa); B — Slope bottom width (m).

[0139] d≥1.8H, 0.12≤d / L<0.139 and 8 <T * When the wave pressure and wave surface elevation are ≤9, the values ​​of wave pressure and wave surface elevation can be calculated according to the following formulas (18) and (19):

[0140]

[0141]

[0142] In the formula: T * —Dimensionless period in actual wave conditions; — Represents various quantities such as wave pressure and wave surface elevation; ——Take T * =8 and the H / d value of the actual waveform; ——Take T * =9 and the H / d value of the actual wave condition.

[0143] Step 4: Run the numerical simulation program to perform the calculations.

[0144] Please see Figure 4 To ensure that the simulated waves impacting the bank have sufficient time to stabilize without being affected by wave reflection, a calculation time of 40 seconds is used. To accurately locate wave crests and troughs, the data output interval is set to 2 seconds. Calculation results and water pressure contour maps are output at times of 8 seconds, 12 seconds, 16 seconds, 20 seconds, 24 seconds, 28 seconds, and 36 seconds, respectively.

[0145] Because the interaction between waves and the bank slope occurs 36 seconds before the incident wave, the reflected waves interfere with each other, resulting in unstable wave morphology and water pressure distribution. Based on numerical simulation results, the wave waveform near the bank slope is relatively regular and stable; therefore, we will analyze the wave morphology and water pressure distribution at time 36, after they have stabilized.

[0146] Step 5: Analyze the numerical simulation results in conjunction with the standard calculation results.

[0147] Please see Figure 5To ensure that the calculation results are more contrastive and referential, the differences between the results of the impact force calculated by the two methods are compared through calculation of different working conditions, so as to further carry out analysis. There are 5 working conditions, which are working condition 1: d = 10 m, H = 4 m, L = 160 m; working condition 2: d = 10 m, H = 5 m, L = 142 m; working condition 3: d = 10 m, H = 3 m, L = 170 m; working condition 4: d = 15 m, H = 2 m, L = 150 m; working condition 5: d = 15 m, H = 3 m, L = 170 m. According to the calculation results, the results of the specification calculation are generally smaller, and the value of the numerical simulation calculation result is 3-5.5 times of the result of the specification calculation.

[0148] Step 6: According to the actual working condition, the impact force of the wave on the straight wall type rock slope is evaluated.

[0149] See Figure 5 and Figure 6 , the calculation results of the specification calculation are numerically conservative, and considering the actual working condition construction needs of the marine engineering and the complex marine environment, the specification calculation is actually less safe than the result of the numerical simulation calculation. The numerical simulation method can obtain a water pressure cloud map, and can better analyze the impact force of the wave on the straight wall type rock slope, and is more intuitive and more in line with the engineering needs than the specification calculation. Therefore, according to the numerical simulation results, a formula for calculating the wave impact force of the embodiment is fitted:

[0150]

[0151] In the formula, p bc is the wave impact force intensity (kPa), d is the water depth in front of the slope (m), H is the wave height at the place where the slope is located (m), and L is the wave length (m).

[0152] The conclusion and the formula are used as a reference for evaluating the wave impact on the straight wall type rock slope in the actual engineering construction of the embodiment.

[0153] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should be covered in the scope of the claims and the specification of the present application.

Claims

1. A method for assessing the impact force of waves on a straight-walled rocky bank slope, characterized in that, This method accurately assesses the impact force of waves on rocky bank slopes by combining the construction of a three-dimensional numerical model with standard calculations, including the following steps: Step S1: Based on the geometric morphology, structural characteristics and geological composition of the straight-wall rock slope, construct a three-dimensional numerical model to simulate the geometric morphology and physical properties of the slope structure; Step S2: Based on the actual marine environmental conditions and wave characteristics, set the boundary conditions of the numerical model, including wave parameters, shoreline material properties, and surrounding environmental factors; Step S3: Select a suitable numerical calculation method for the interaction between waves and rocky banks, and set the calculation method and parameters of the numerical simulation program, including the numerical method used and the time step; Step S4: Run the numerical simulation program to simulate the stress-strain response of the rocky bank under wave action and obtain pore water pressure and stress distribution data; Step S5: Combine the standard calculation results, analyze the numerical simulation results, compare and verify the accuracy of the numerical simulation results, and adjust the model parameters to optimize the results; Step S6: Based on the simulation results and actual working conditions, assess the impact force of waves on the vertical rock slope and provide targeted recommendations for engineering design and safety protection.

2. The method for assessing the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S1, the method for constructing a three-dimensional numerical model includes establishing a 1:1 numerical model of wave propagation and the vertical rock slope based on the main morphology of the vertical rock slope and considering actual conditions using numerical simulation software, while inputting the characteristics of the waves, the geometry of the vertical rock slope, and material property parameters.

3. The method for assessing the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S2, the boundary conditions of the numerical model include important numerical simulation settings options such as the input of the wave source, water depth distribution, geometry of the straight-walled rocky bank, and the coefficient of friction of the bed.

4. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S3, the calculation method and parameters are set according to the selected specifications and formulas, and the impact force of the waves on the model is calculated by combining the wave parameters and the geometry of the model.

5. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 4, characterized in that, In step S3, the calculation method uses the formula based on the impact force calculation section of the standard "Harbor Hydrology Code" JTS145-2-2013, and the calculation is performed according to the following steps: Determine the wave state of waves acting on a vertical rock slope; Calculate the impact forces on a straight-walled rock slope under the action of wave crests and troughs.

6. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 5, characterized in that, In step S3, the wave state of the wave acting on the vertical rock slope is determined based on the slope and wave conditions. The conditions for the generation of standing waves should satisfy that the wave crest line is approximately parallel to the slope, and the slope length is greater than one wavelength. Additionally, the following formula must also be satisfied: In the formula: —Mean wave period, in seconds; d —Water depth in front of the bank slope, in meters; H —Wave height of the wave at the bank slope, in meters; g —Acceleration due to gravity, in meters per second. 2 .

7. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 5, characterized in that, In step S3, the impact force on the straight-walled rock slope under the action of wave crests and troughs is calculated using corresponding formulas based on the characteristics of the slope and the waves. When d≥1.8H and d / L=0.05~0.12, H is the wave height of the wave at the location of the shore slope, L is the wavelength, and the impact force under the action of the wave crest is calculated according to the wave pressure distribution diagram of the wave crest action in the standard "Harbor Hydrology Code" JTS145-2-2013, as follows: ① The wavefront elevation is calculated using the following formula: In the formula: η c —Wave surface elevation, in meters; d —Water depth in front of the bank slope, in meters; B η m — correction factor; T* — Dimensionless period, in seconds; —Average period, in seconds; g —Acceleration due to gravity, in m / s² 2 ; ② Above the still water surface h c The slope wave pressure intensity at the location is calculated according to formulas (7) to (9): n=[0.636618+4.23264(H / d) 1.67 ,1.0] (9) Where: h c —Wave pressure intensity p ac The position of the point of action above the still water surface, in meters (m); p ac —with h c The corresponding slope wave pressure intensity, in kPa; n—the exponent of the wave pressure intensity distribution curve above the still water surface, its value is the larger of the two numbers in the formula; p oc —Wave pressure intensity on still water surface, unit: kPa; γ —Specific weight of water, unit: kN / m 3 ; ③ Wave pressure intensity p on still water surface oc The wave pressure intensity at other characteristic points on the slope is calculated according to equation (10), when p bc >p oc Take p bc =p oc , where p bc The slope wave pressure intensity at a water depth of d / 2, in kPa: Where: p—wave pressure intensity at each characteristic point on the slope, in kPa; A p B p q—Crest action coefficient, determined according to the corresponding parameter table; ④ Total horizontal wave force P per unit length of bank slope c Calculate according to formula (11): In the formula: P c —Total horizontal wave force per unit length of bank slope, expressed in kN / m; p dc —Wave pressure intensity at the bottom of the slope, in kPa; p bc —Slope wave pressure intensity corresponding to water depth d / 2, in kPa; ⑤ Total horizontal wave moment M per unit length of bank slope c Calculate according to formula (12): Where: M c —Total horizontal wave moment per unit length of bank slope, expressed in kN·m / m; ⑥ Wave buoyancy force P per unit length of slope bottom surface uc Calculate according to formula (13): In the formula: P uc — Wave buoyancy force per unit length of slope bottom surface, in kN / m; B — Slope bottom width, in m; When d≥1.8H and d / L=0.05~0.12, the impact force under wave trough action can be calculated according to the following provisions based on the wave pressure distribution diagram under wave trough action in the standard "Harbor Hydrology Code" JTS145-2-2013: ① Wave trough and wave surface elevation η t Calculate according to formula (14): In the formula: η t —Wave trough elevation, in meters; A p B p q—the trough effect coefficient, determined according to the parameter table in the standard "Harbor Hydrology Standard" JTS145-2-2013; ② The wave pressure intensity p at each characteristic point on the slope is calculated according to (15), with coefficient A p B p q is determined according to the corresponding parameter table, when p dt >p ot When, take p dt =p ot , where p dt The wave pressure intensity at the bottom of the slope is expressed in kPa; p ot The wave pressure intensity corresponding to the wave trough and wave surface, in kPa: Where: p—wave pressure intensity at each characteristic point on the slope, in kPa; ③ Total horizontal wave force P per unit length of slope t Calculate according to formula (16): In the formula: P t —Total horizontal wave force per unit length of slope, expressed in kN / m; p dt —Wave pressure intensity at the bottom of the slope, in kPa; p ot —The wave pressure intensity corresponding to the wave trough and wave surface, in kPa; ④ The downward wave force P on the slope bottom surface per unit length ut Calculate according to formula (17): In the formula: P ut —The downward wave force per unit length on the bottom surface of a slope, expressed in kN / m; p dt — Wave pressure intensity at the bottom of the slope, in kPa; B — Slope bottom width, in m; d≥1.8H, 0.12≤d / L<0.139 and 8 <T * When the wave pressure is ≤9, the wave surface elevation is calculated according to the following formulas (18) and (19): In the formula: T * —Dimensionless period in actual wave conditions; — Represents wave pressure and wave surface elevation; —Take T * =8 and the H / d value of the actual waveform; ——Take T * =9 and the H / d value of the actual wave condition.

8. The method for assessing the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S4, the calculation of the numerical simulation program includes: Numerical simulation programs were used to simulate the propagation, reflection, refraction, and disturbance of waves around the breakwater; Numerical simulation programs were used to calculate wave height, wave pressure, wave velocity parameters, and the interaction between waves and vertical rock slopes, ultimately yielding specific impact force results.

9. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S5, the analysis of numerical simulation results includes comparing the differences between the standard calculation results and the numerical simulation calculation results. Specifically, by calculating the impact force results under different working conditions, the differences between the impact force results calculated by the two methods are analyzed in order to carry out further analysis.

10. The method for evaluating the impact force of waves on a straight-walled rocky bank slope according to claim 1, characterized in that, In step S6, the assessment of the impact force of waves on the vertical rock slope includes evaluating and analyzing the calculation results of the wave impact force in combination with the actual working conditions and the needs of marine engineering construction, and using this as a reference for actual engineering construction.

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