A method and system for evaluating the stability performance of a wave-dissipating breakwater of a combined seawall

Abstract

The present invention belongs to the technical field of breakwater for port, coastal and offshore engineering, and discloses a method and system for evaluating the stability performance of a wave-dissipating breakwater of a combined seawall. The method includes: obtaining the hydrological data of the area where the combined seawall is located and the structural section data of the combined seawall, establishing a wave dynamic numerical model, using the wave dynamic numerical model to simulate the wave run-up on the embankment body of the target combined seawall and the overtopping of the wave-dissipating breakwater crest, calculating the wave force and wave moment of the wave-dissipating breakwater, and determining the wave load index; calculating the self-weight of the wave-dissipating breakwater of the target combined seawall, the connection force between the wave-dissipating breakwater and the sloping seawall and its moment on the overturning fulcrum, obtaining the gravity and gravity moment of the wave-dissipating breakwater, and determining the structural index of the wave-dissipating breakwater; calculating the safety factors of anti-overturning stability and anti-sliding stability according to the wave load index and the structural index of the wave-dissipating breakwater. The present invention improves the accuracy of disaster warning and has practical application value.

Description

Technical Field

[0001] The present invention belongs to the technical field of breakwaters in port, coastal and offshore engineering, and discloses a method and system for evaluating the stability performance of a wave-dissipating breakwater of a combined seawall. Background Art

[0002] With the proposal of a pro-sea living environment, in order to reduce the design elevation of the seawall, the engineering community has proposed a combined seawall, that is, a small trapezoidal wave-dissipating breakwater is arranged on the offshore side of the sloping seawall to reduce the energy of storm surges and sea waves, reduce their run-up along the sloping seawall, prevent them from large-scale overtopping the crest, and impact the crest and the back slope. It has a more complex structure than single-slope and compound seawalls. The wave motion caused by the wave-dissipating breakwater includes strong breaking and overtopping flow impact phenomena. The calculation of wave loads is more complex, and the calculation of the stability of the wave-dissipating breakwater is also more difficult.

[0003] At present, the "Code for Design of Breakwaters and Revetments" gives the calculation formulas for the anti-sliding and anti-overturning stability of the revetment breast wall of the cross-section type of the sloping revetment with a breast wall and a shoulder platform in the ultimate limit state of bearing capacity design. The "Code for Design of Seawall Engineering" makes relevant regulations on the calculation of the stability coefficients of the overall seawall, the seawall retaining wall, and the wave-breaking wall, and gives the minimum safety factors for the anti-sliding stability and anti-overturning stability checks. The "Code for Port and Waterway Hydrology" divides the wave states of vertical-wall structures on open and buried rubble beds into three types: standing wave, far-breaking wave, and near-breaking wave, and respectively gives the calculation methods for the wave pressure on the wall surface, the total horizontal wave force, and the wave uplift force on the bottom surface of the wall, and gives the regulations on the wave run-up and overtopping quantity at the crest of the sloping structure.

[0004] These calculation methods are empirical formulas based on theoretical derivation and experimental data for conventional types of seawalls and revetments. For the calculation of wave forces and stability of this new type of combined seawall, there are no theoretical formulas and specifications to follow. Secondly, these calculation methods are derived based on linear wave theory and experimental data, and their applicability is not clear for the calculation of wave loads, wave run-up, and overtopping at the crest caused by extreme non-linear wave actions such as storm surges and tsunamis. In addition, the "Code for Port and Waterway Hydrology" only stipulates the calculation of wave forces when the wave crest and wave trough act, which makes the anti-sliding stability and anti-overturning safety coefficients in the "Code for Design of Seawall Engineering" can only be calculated under the instantaneous action of the wave crest and wave trough, and cannot consider the cumulative action under the entire wave period, and cannot obtain a comprehensive evaluation of the stability safety. Summary of the Invention

[0005] To overcome the problems existing in the related technologies, the disclosed embodiments of the present invention provide a method and system for evaluating the stability performance of a wave-dissipating dike of a combined seawall. Due to the complex form of the combined seawall, when disasters such as storm surges and tsunamis occur, the non-linear wave actions such as wave breaking, slamming, overtopping, vortex and air-water mixing are strong, making it impossible to have a theoretical calculation method for the wave forces on the wave-dissipating dike, which brings difficulties to the calculation of the stability performance of the wave-dissipating dike. The purpose of the present invention is to provide a method and a calculation system for evaluating the stability performance of a wave-dissipating dike of a combined seawall, which can determine the stability safety assessment of the wave-dissipating dike according to the cross-sectional dimensions and hydrological conditions of the actual combined seawall.

[0006] The technical solution is as follows: A method for evaluating the stability performance of a wave-dissipating dike of a combined seawall, comprising:

[0007] S1. Establish a wave dynamic numerical model, and use the preset Navier-Stokes equation and THINC algorithm to establish a numerical model for calculating wave hydrodynamic elements of the target combined seawall, which is used to solve the wave pressure and load acting on the wave-dissipating dike;

[0008] S2. According to the hydrological data of the area where the combined seawall is located and the cross-sectional data of the seawall structure, use the wave dynamic numerical model to simulate the wave run-up on the seawall body and the overtopping on the crest of the wave-dissipating dike of the target combined seawall, calculate the wave forces and wave moments of the wave-dissipating dike, and determine the wave load index;

[0009] S3. According to the hydrological data and the cross-sectional data of the seawall structure, calculate the self-weight of the wave-dissipating dike of the target combined seawall, the connection force between the wave-dissipating dike and the sloping seawall and its moment about the overturning fulcrum, obtain the gravity and gravity moment of the wave-dissipating dike, and determine the structure index of the wave-dissipating dike;

[0010] S4. According to the wave load index and the structure index of the wave-dissipating dike, calculate the safety factors of anti-overturning stability and anti-sliding stability, compare with the safety factors, and form a stability safety assessment result.

[0011] Before step S1, it is necessary to:

[0012] Obtain the hydrological data of the area where the combined seawall is located, and the representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of the incident wave;

[0013] Obtain the cross-sectional data of the combined seawall structure, including the height, slope and facing structure data of the sloping seawall in the combined seawall, as well as the position, front slope, height, crest width, rear slope and facing structure data of the wave-dissipating dike.

[0014] In step S2, determine the wave load index, including: instantaneous wave force and moment index, cumulative wave impulse and impulse moment index within a single wave period;

[0015] The instantaneous wave force and moment indexes include: the horizontal component of the load acting on the wave-dissipating embankment's wave-facing surface, top surface, and back wave surface , the vertical component of the load acting on the wave-dissipating embankment's wave-facing surface, top surface, and back wave surface , the uplift force acting on the bottom surface of the wave-dissipating embankment , the load moment of the wave acting on the wave-dissipating embankment's wave-facing surface, top surface, and back wave surface , the uplift force moment of the wave acting on the bottom surface of the wave-dissipating embankment , the anti-sliding effect force of the wave load along the slope of the sloping seawall , the anti-sliding effect force of the wave load along the slope of the sloping seawall ;

[0016] The cumulative wave impulse and impulse moment indexes within a single wave period include: the anti-sliding force impulse of the wave load within a single wave period , the sliding force impulse of the wave load within a single wave period , the overturning impulse moment of the wave load within a single wave period .

[0017] Furthermore, the horizontal component of the load acting on the wave-dissipating embankment's wave-facing surface, top surface, and back wave surface is calculated by a wave dynamic numerical model, and the expression is:

[0018] ;

[0019] In the formula, is the surface of the wave-facing surface, top surface, and back wave surface of the seawall, is the wave pressure acting at each point on the seawall, is the unit normal vector perpendicular to the wave-facing surface, top surface, and back wave surface of the seawall, is the Dirac function, is the projection of the surface area of the wave-facing surface, top surface, and back wave surface of the seawall in the direction, is calculus;

[0020] The vertical component of the load acting on the wave-dissipating embankment's wave-facing surface, top surface, and back wave surface , is calculated by a wave dynamic numerical model, and the expression is:

[0021] ;

[0022] In the formula, is the projection of the surface area of the wave-facing surface, top surface, and back wave surface of the seawall in the direction;

[0023] The uplift force of the wave acting on the bottom surface of the wave-dissipating breakwater , the expression is:

[0024] ;

[0025] In the formula, is the time history of the wave pressure at the bottom corner of the wave-facing surface of the wave-dissipating breakwater, is the time history of the wave pressure at the bottom corner of the wave-back surface of the wave-dissipating breakwater, is the distance between the two bottom corners of the wave-dissipating breakwater, What is solved is the force at each moment;

[0026] The load moment of the wave acting on the wave-facing surface, top surface, and wave-back surface of the wave-dissipating breakwater , which is calculated by the wave dynamic numerical model, and the expression is:

[0027] ;

[0028] In the formula, is the lever arm from the acting point of the wave load force at a certain point on the surface of the wave-dissipating breakwater to the overturning fulcrum at the bottom surface of the wave-dissipating breakwater, is the surface of the wave-facing surface, top surface, and wave-back surface of the seawall;

[0029] The uplift force moment of the wave acting on the bottom surface of the wave-dissipating breakwater , the expression is:

[0030] ;

[0031] In the formula, is the lever arm from the acting point of the resultant force of the wave uplift force to the overturning fulcrum at the bottom surface of the wave-dissipating breakwater;

[0032] The anti-sliding effect force of the wave load along the slope of the slope seawall , the expression is:

[0033] ;

[0034] In the formula, is the slope angle of the slope of the slope seawall;

[0035] The anti-sliding effect force of the wave load along the slope of the slope seawall , the expression is:

[0036] .

[0037] Furthermore, the anti-sliding force impulse of the wave load within a single wave period , the expression is:

[0038] ;

[0039] Sliding force impulse of wave load within a single wave period , and the expression is:[[]]

[0040] ;

[0041] Overturning impulse moment of wave load within a single wave period , and the expression is:[[]]

[0042] ;

[0043] In the formula, is the wave period. For solitary waves such as tsunamis , is the attenuation coefficient, , is the height of the solitary wave, is the still water depth, is the wave speed of the solitary wave.[[]]

[0044] In step S3, the breakwater structure indexes include: instantaneous gravity and moment indexes, cumulative gravity impulse and impulse moment indexes within a single wave period;

[0045] The instantaneous gravity and moment indexes include: the self - gravity of the breakwater , the internal force at the connection between the breakwater and the sloping seawall, the self - gravity moment of the breakwater , the internal force moment at the connection between the breakwater and the sloping seawall , the anti - sliding force of the self - gravity of the breakwater , the sliding force of the self - gravity of the breakwater ;

[0046] The cumulative gravity impulse and impulse moment indexes within a single wave period include: the cumulative anti - sliding impulse of the self - gravity of the breakwater within a single wave period , the cumulative sliding impulse of the self - gravity of the breakwater within a single wave period , the cumulative anti - overturning impulse moment of the self - gravity of the breakwater within a single wave period .

[0047] Furthermore, the self - gravity moment of the breakwater , and the expression is:[[]]

[0048] ;

[0049] In the formula, is the lever arm from the acting point of the resultant force of the self - gravity of the breakwater to the overturning fulcrum at the bottom of the breakwater;

[0050] The internal force moment at the connection between the breakwater and the sloping seawall , determined according to their connection method. If the connection method is direct placement, the moment at the connection is zero. If the connection method is anchor bolt anchorage, its maximum moment expression is:

[0051] ;

[0052] In the formula, is the shear load borne by the anchor bolts at the connection, is the lever arm from the acting point of the shear load of the anchor bolts at the connection to the tipping fulcrum at the bottom of the wave-dissipating breakwater;

[0053] The anti-sliding force of the self-weight of the wave-dissipating breakwater , and the expression is:

[0054] ;

[0055] In the formula, is the slope angle of the slope of the sloping seawall;

[0056] The sliding force of the self-weight of the wave-dissipating breakwater , and the expression is:

[0057] ;

[0058] The cumulative anti-sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0059] ;

[0060] In the formula, is the wave period;

[0061] The cumulative sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0062] ;

[0063] The cumulative anti-tipping impulse moment of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0064] ;

[0065] The cumulative anti-tipping impulse moment of the shear load at the connection within a single wave period , and the expression is:

[0066] ;

[0067] In step S4, the safety factor of anti-sliding stability, and the expression is:

[0068] ;

[0069] In the formula, is the anti-sliding stability safety factor, is the minimum value within its time history range for anti-sliding stability safety, is the friction coefficient between the wave-dissipating breakwater and the connecting interface of the slope seawall.

[0070] Furthermore, the instantaneous minimum value of the anti-sliding stability safety factor is:

[0071] ;

[0072] The cumulative average anti-sliding stability safety factor within a single-wave period is calculated by the following formula:

[0073] ;

[0074] The cumulative average anti-overturning stability safety factor within a single-wave period is calculated by the following formula:

[0075] ;

[0076] In the formula, is the anti-overturning impulse moment of the shear load at the cumulative connection within a single-wave period.

[0077] Another object of the present invention is to provide a wave-dissipating breakwater stability performance evaluation system for a combined seawall, which is implemented by the wave-dissipating breakwater stability performance evaluation method of the combined seawall, and the system includes:

[0078] A hydrological module, which integrates the hydrological data of the area where the combined seawall is located, obtains the hydrological data of the area where the combined seawall is located, and has representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of the incident wave;

[0079] A seawall structure cross-section data module, which is used to obtain the combined seawall structure cross-section data, including the height, slope and facing structure data of the slope seawall in the combined seawall, as well as the position, front slope gradient, height, crest width, rear slope gradient and facing structure data of the wave-dissipating breakwater;

[0080] A wave dynamic numerical model module, which is used to establish a numerical model for calculating wave hydrodynamic elements of the target combined seawall by using the preset Navier-Stokes equation and THINC algorithm, and is used to solve the wave pressure and load acting on the wave-dissipating breakwater;

[0081] The wave load index determination module is used to simulate the wave run-up on the embankment body and the overtopping on the crest of the wave-dissipating embankment of the target combined seawall by using a wave dynamic numerical model according to the hydrological data and the seawall structure section data in the area where the combined seawall is located, calculate the wave force and wave moment of the wave-dissipating embankment, and determine the wave load index;

[0082] The wave-dissipating embankment structure index determination module is used to calculate the self-weight of the wave-dissipating embankment of the target combined seawall, the connection force between the wave-dissipating embankment and the slope seawall, and the moment thereof on the tipping fulcrum according to the hydrological data and the seawall structure section data, obtain the gravity and gravity moment of the wave-dissipating embankment, and determine the wave-dissipating embankment structure index;

[0083] The stability evaluation calculation module is used to calculate the safety factors of anti-tipping stability and anti-sliding stability according to the wave load index and the wave-dissipating embankment structure index, compare with the safety factors, and form a stability safety evaluation result

[0084] Combining all the above technical solutions, the beneficial effects of the present invention are as follows:

[0085] As a creative auxiliary evidence for the claims of the present invention, it is also reflected in the following important aspects:

[0086] The stability evaluation method and system of the present invention solve the problem that there is no theoretical formula and specification for calculating the wave action force and stability of this new type of combined seawall, and can more accurately conduct personalized stability safety evaluation on the wave-dissipating embankment according to the cross-sectional dimensions and hydrological conditions of the actual combined seawall, improving the accuracy of disaster warning. The evaluation method is scientific and rigorous, the evaluation system is logically rigorous and highly operable, and the stability indicators considered meet the actual requirements of engineering design, having practical application value.

[0087] The present invention proposes stability indicators such as the cumulative average anti-sliding stability safety factor within a single wave period and the cumulative average anti-tipping stability safety factor within a single wave period. Such indicators can fully consider the destructive effect of time accumulation on the stability of the seawall. On the one hand, the instantaneous wave indicators are oscillatory, and there may be a situation where the stability of the seawall does not meet the requirements only at a very short moment while meeting the requirements at most moments. The cumulative indicators can avoid the inaccuracy of judging the stability of the seawall caused by the oscillation of the instantaneous wave action. On the other hand, the instability of the seawall is a time process, and the cumulative indicators can more comprehensively provide the time effect, helping the designer to measure situations such as instantaneous instability and cumulative stability.

[0088] The cross-section data module of the seawall structure in the system of the present invention can establish corresponding cross-section models for composite seawalls of any size and facing structure form, making the system of the present invention have wide applicability and application value. The wave dynamic numerical model module can use the wind-wave conditions under normal sea conditions and extreme disaster sea conditions such as typhoons, storm surges, and tsunamis as input parameters to simulate wave loads, wave run-up, and overtopping at the dike crest generated by strong non-linear wave actions such as wave breaking, slamming, overtopping, vortex, and air-water mixing, solving the problem that there is no theoretical calculation method for the wave forces on the wave-dissipating dike, which greatly expands the applicable conditions and scope of the evaluation system.

[0089] The stability evaluation method and system of the present invention thus obtained first quantify the wave action and the complex combination form of the seawall using wave hydrological characteristic values and the cross-section data of the composite seawall structure, and then use the engineering design requirement parameter values to characterize the wave load on the wave-dissipating dike based on the numerical model. On the basis of the traditional instantaneous minimum anti-sliding stability safety factor and instantaneous minimum anti-overturning stability safety factor, stability indexes such as the cumulative average anti-sliding stability safety factor within a single wave period and the cumulative average anti-overturning stability safety factor within a single wave period are proposed. Based on these four stability indexes and combined with the safety factor regulations in the "Code for Design of Seawall Engineering", the anti-overturning and anti-sliding stability evaluation results of the wave-dissipating dike structure in the composite seawall are obtained. BRIEF DESCRIPTION OF THE DRAWINGS

[0090] The drawings here are incorporated into the specification and form a part of this specification, showing embodiments consistent with the present disclosure and, together with the specification, are used to explain the principles of the present disclosure;

[0091] Figure 1 is a schematic diagram of the cross-section of the composite seawall structure provided by an embodiment of the present invention;

[0092] Figure 2 is a flowchart of the method for evaluating the stability performance of the wave-dissipating dike of the composite seawall provided by an embodiment of the present invention;

[0093] Figure 3 is a schematic diagram of the loads on the wave-dissipating dike provided by an embodiment of the present invention;

[0094] Figure 4 is a schematic diagram of the system for evaluating the stability performance of the wave-dissipating dike of the composite seawall provided by an embodiment of the present invention;

[0095] Figure 5 is a schematic diagram of the THINC format provided by an embodiment of the present invention;

[0096] Figure 6 is a time history curve diagram calculated by the wave dynamic numerical model of the present invention;

[0097] Figure 7Time history curve diagram calculated by the wave power numerical model of the present invention;

[0098] Figure 8 Time history curve diagram calculated by the wave power numerical model of the present invention;

[0099] Figure 9 For the present invention Time history curve diagram of the anti-sliding effect force of the wave load along the slope of the sloping seawall;

[0100] Figure 10 For the present invention Time history curve diagram of the anti-sliding effect force of the wave load along the slope of the sloping seawall;

[0101] Figure 11 For the present invention Time history curve diagram calculated by the wave power numerical model of the moment of the wave load acting on the wave-facing surface, top surface, and back wave surface of the wave-dissipating breakwater;

[0102] Figure 12 For the present invention , Time history curve diagram calculated by the wave power numerical model of the moment of the wave uplift force acting on the bottom surface of the wave-dissipating breakwater;

[0103] Figure 13 For the present invention Time history curve diagram of the anti-sliding force impulse of the wave load within a single wave period, calculated by the wave power numerical model;

[0104] Figure 14 For the present invention Time history curve diagram of the sliding force impulse of the wave load within a single wave period, calculated by the wave power numerical model;

[0105] Figure 15 For the present invention Time history curve diagram of the overturning impulse moment of the wave load within a single wave period, calculated by the wave power numerical model;

[0106] Figure 16 Time history curve diagram of the instantaneous minimum anti-sliding stability safety factor of the present invention;

[0107] Figure 17 Time history curve diagram of the instantaneous minimum anti-overturning stability safety factor of the present invention;

[0108] Figure 18 Time history curve diagram of the cumulative average anti-sliding stability safety factor within a single wave period of the present invention;

[0109] Figure 19 Time history curve diagram of the cumulative average anti-overturning stability safety factor within a single wave period of the present invention;

[0110] In the figure: 1. Hydrological module; 2. Cross-section data module of seawall structure; 3. Numerical model module of wave dynamics; 4. Module for determining wave load index; 5. Module for determining structure index of wave-dissipating breakwater; 6. Stability evaluation calculation module. Specific implementation manners

[0111] In order to make the above objects, features and advantages of the present invention more obvious and understandable, the specific implementation manners of the present invention will be described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific implementations disclosed below.

[0112] For the stability evaluation of the wave-dissipating breakwater of the sea-reaching residential combined seawall, in the current "Design Code for Breakwaters and Revetments" and "Design Code for Seawall Engineering", only methods for calculating the stability of the revetment breast wall with the cross-section type of the sloping revetment with breast wall and shoulder platform are given. The "Hydrology Code for Ports and Waterways" only gives calculation methods for the wave loads of vertical-wall structures on open and sunken rubble beds. These calculation methods are empirical formulas based on theoretical derivations and experimental data for conventional types of seawalls and revetments. Since the wave motions caused by the wave-dissipating breakwaters of the new type of combined seawall include strong breaking and overtopping flow impact phenomena, the calculation of their wave loads is more complex and difficult. There are no theoretical formulas and codes to follow for the calculation of wave forces and stability of this configuration. In addition, the "Hydrology Code for Ports and Waterways" only stipulates the calculation of wave forces when the wave crest and wave trough act, which makes the anti-sliding stability and anti-overturning stability safety factors in the "Design Code for Seawall Engineering" can only be calculated under the instantaneous action of the wave crest and wave trough, and cannot consider the cumulative action under the entire wave period, and cannot obtain a comprehensive evaluation of the stability safety.

[0113] To overcome the problems existing in the related technologies, the present invention calculates the non-linear wave loads such as wave breaking, slamming, overtopping, vortex and air-water mixing of the wave-dissipating breakwater at each moment according to the cross-section dimensions and hydrological conditions of the actual combined seawall, so as to propose stability indexes of the cumulative average anti-sliding stability safety factor and the cumulative average anti-overturning stability safety factor within a single wave period on the basis of the traditional instantaneous minimum anti-sliding stability safety factor and the instantaneous minimum anti-overturning stability safety factor, and provide more information for designers in special working conditions such as instantaneous oscillatory instability and cumulative stability, so as to comprehensively evaluate the stability safety of the wave-dissipating breakwater.

[0114] Example 1, as Figure 2 shown, the method for evaluating the stability of the wave-dissipating breakwater of the combined seawall provided by the embodiment of the present invention includes:

[0115] S1. Establish a numerical model of wave dynamics. Use the preset Navier-Stokes equations and the THINC algorithm to establish a numerical model for calculating wave hydrodynamic elements of the target combined seawall, which is used to solve the wave pressure and load acting on the wave-dissipating seawall.

[0116] S2. According to the hydrological data and the seawall structure cross-section data of the area where the combined seawall is located, use the numerical model of wave dynamics to simulate the wave run-up on the seawall body and the overtopping on the crest of the wave-dissipating seawall of the target combined seawall, calculate the wave force and wave moment of the wave-dissipating seawall, and determine the wave load index.

[0117] S3. According to the hydrological data and the seawall structure cross-section data, calculate the self-weight of the wave-dissipating seawall of the target combined seawall, the connection force between the wave-dissipating seawall and the sloping seawall, and the moment acting on the tipping fulcrum, obtain the gravity and gravity moment of the wave-dissipating seawall, and determine the structure index of the wave-dissipating seawall.

[0118] S4. According to the wave load index and the structure index of the wave-dissipating seawall, calculate the safety factors of anti-tipping stability and anti-sliding stability, compare with the safety factors, and form the stability safety assessment result.

[0119] Before step S1, it is necessary to perform:

[0120] Obtain the hydrological data of the area where the combined seawall is located, including the representative wave hydrological characteristic values, such as water depth, tide level, tidal current velocity, wave height and period of the incident wave.

[0121] Obtain the combined seawall structure cross-section data, including the height, slope and facing structure data of the sloping seawall in the combined seawall, as well as the position, front slope, height, crest width, back slope and facing structure data of the wave-dissipating seawall.

[0122] In step S2, determine the wave load index, including: instantaneous wave force and moment index, cumulative wave impulse and impulse moment index within a single wave period.

[0123] The instantaneous wave force and moment index includes: the horizontal component of the load acting on the wave-facing surface, top surface and wave-back surface of the wave-dissipating seawall , the vertical component of the load acting on the wave-facing surface, top surface and wave-back surface of the wave-dissipating seawall , the uplift force acting on the bottom surface of the wave-dissipating seawall , the load moment acting on the wave-facing surface, top surface and wave-back surface of the wave-dissipating seawall , the uplift force moment acting on the bottom surface of the wave-dissipating seawall , the anti-sliding effect force of the wave load along the slope of the sloping seawall , the anti-sliding effect force of the wave load along the slope of the sloping seawall ;

[0124] The horizontal component of the load exerted by waves on the wave-dissipating dyke's wave-facing surface, top surface, and back surface is calculated by a wave dynamic numerical model, and the expression is:

[0125] ;

[0126] In the formula, is the surface of the wave-facing surface, top surface, and back surface of the seawall, is the wave pressure acting at each point on the seawall, is the unit normal vector perpendicular to the wave-facing surface, top surface, and back surface of the seawall, is the Dirac function, is the projection of the surface area of the wave-facing surface, top surface, and back surface of the seawall in the direction, is calculus;

[0127] The vertical component of the load exerted by waves on the wave-facing surface, top surface, and back surface of the wave-dissipating dyke , is calculated by a wave dynamic numerical model, and the expression is:

[0128] ;

[0129] In the formula, is the projection of the surface area of the wave-facing surface, top surface, and back surface of the seawall in the direction;

[0130] The uplift force exerted by waves on the bottom surface of the wave-dissipating dyke , and the expression is:

[0131] ;

[0132] In the formula, is the wave pressure time history at the bottom corner of the wave-facing surface of the wave-dissipating dyke, is the wave pressure time history at the bottom corner of the back surface of the wave-dissipating dyke, is the distance between the two bottom corners of the wave-dissipating dyke, and what is solved is the force at each moment;

[0133] The load moment exerted by waves on the wave-facing surface, top surface, and back surface of the wave-dissipating dyke , is calculated by a wave dynamic numerical model, and the expression is:

[0134] ;

[0135] In the formula, is the lever arm from the acting point of the wave load force at a certain point on the surface of the wave-dissipating breakwater to the overturning fulcrum at the bottom of the wave-dissipating breakwater. are the surfaces of the wave-facing side, the top surface, and the back wave side of the seawall.

[0136] The buoyancy moment of the wave acting on the bottom surface of the wave-dissipating breakwater , and the expression is:

[0137] ;

[0138] In the formula, is the lever arm from the acting point of the resultant buoyancy force of the wave to the overturning fulcrum at the bottom of the wave-dissipating breakwater;

[0139] The anti-sliding effect force of the wave load along the slope of the sloping seawall , and the expression is:

[0140] ;

[0141] In the formula, is the slope angle of the slope of the sloping seawall;

[0142] The cumulative wave impulse and impulse moment indexes within the single-wave period mentioned above include: the anti-sliding force impulse of the wave load within the single-wave period , the sliding force impulse of the wave load within the single-wave period , and the overturning impulse moment of the wave load within the single-wave period .

[0143] The anti-sliding effect force of the wave load along the slope of the sloping seawall , and the expression is:

[0144] .

[0145] The anti-sliding force impulse of the wave load within the single-wave period , and the expression is:

[0146] ;

[0147] The sliding force impulse of the wave load within the single-wave period , and the expression is:

[0148] ;

[0149] The overturning impulse moment of the wave load within the single-wave period , and the expression is:

[0150] ;

[0151] In the formula, is the wave period;

[0152] This index can fully consider the damaging effect of time accumulation on the stability of the seawall. On the one hand, the instantaneous wave index has oscillation, and it may occur that the seawall stability does not meet the requirements only at a very short moment while meeting the requirements at most moments. The cumulative index can avoid the inaccuracy of the seawall stability judgment caused by the oscillation of the instantaneous wave action. On the other hand, the instability of the seawall is a time process, and the cumulative index can more comprehensively provide the time effect to help the designer measure the situations such as instantaneous instability and cumulative stability.

[0153] For solitary waves such as tsunamis, the present invention innovatively proposes:

[0154] ;

[0155] In the formula, is the attenuation coefficient, , is the solitary wave height, is the still water depth, is the wave speed of the solitary wave.

[0156] In the embodiment of the present invention, the wave-dissipating breakwater structure index includes: instantaneous gravity and moment index, cumulative gravity impulse and impulse moment index within a single wave period;

[0157] The instantaneous gravity and moment index includes: the self-gravity of the wave-dissipating breakwater , the internal force at the connection between the wave-dissipating breakwater and the sloping seawall, the self-gravity moment of the wave-dissipating breakwater , the internal force moment at the connection between the wave-dissipating breakwater and the sloping seawall , the anti-sliding force of the self-gravity of the wave-dissipating breakwater , the sliding force of the self-gravity of the wave-dissipating breakwater ; The cumulative gravity impulse and impulse moment index within a single wave period includes: the cumulative anti-sliding impulse of the self-gravity of the wave-dissipating breakwater within a single wave period , the cumulative sliding impulse of the self-gravity of the wave-dissipating breakwater within a single wave period , the cumulative anti-overturning impulse moment of the self-gravity of the wave-dissipating breakwater within a single wave period .

[0158] The self-gravity moment of the wave-dissipating breakwater , and the expression is:

[0159] ;

[0160] In the formula, is the lever arm from the acting point of the resultant force of the self-gravity of the wave-dissipating breakwater to the overturning fulcrum at the bottom of the wave-dissipating breakwater;

[0161] The internal force moment at the connection between the wave-dissipating breakwater and the sloping seawall , determined according to the connection method between the two. If the connection method is direct placement, the moment at the connection is zero. If the connection method is anchor bolt anchorage, the expression for its maximum moment is:

[0162] ;

[0163] In the formula, is the shear load borne by the anchor bolts at the connection, is the lever arm from the action point of the shear load of the anchor bolts at the connection to the overturning fulcrum at the bottom of the wave-dissipating breakwater;

[0164] The anti-sliding force of the self-weight of the wave-dissipating breakwater , and the expression is:

[0165] ;

[0166] In the formula, is the slope angle of the slope of the sloping seawall;

[0167] The sliding force of the self-weight of the wave-dissipating breakwater , and the expression is:

[0168] ;

[0169] The cumulative anti-sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0170] ;

[0171] In the formula, is the wave period;

[0172] The cumulative sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0173] ;

[0174] The cumulative anti-overturning impulse moment of the self-weight of the wave-dissipating breakwater within a single wave period , and the expression is:

[0175] ;

[0176] The cumulative anti-overturning impulse moment of the shear load at the connection within a single wave period , and the expression is:

[0177] ;

[0178] In the embodiment of the present invention, the safety factor of anti-sliding stability, and the expression is:

[0179] ;

[0180] In the formula, is the safety factor of anti-sliding stability, is the minimum value within its time history range for anti-sliding stability safety, is the friction coefficient between the wave-dissipating dike and the connecting interface of the slope-type seawall, which is obtained from the cross-section data of the seawall structure.

[0181] The instantaneous minimum value of the anti-sliding stability safety factor is:

[0182] ;

[0183] The cumulative average anti-sliding stability safety factor within a single wave period is calculated by the following formula:

[0184] ;

[0185] The cumulative average anti-overturning stability safety factor within a single wave period is calculated by the following formula:

[0186] ;

[0187] In the formula, is the anti-overturning impulse moment of the shear load at the cumulative connection within a single wave period.

[0188] It can be understood that the definition of the safety factor of the present invention refers to the specification, resistance effect / hazard effect, but is divided into instantaneous minimum and periodic cumulative average. The "Hydrology Specification for Ports and Waterways" only stipulates the calculation of wave forces when the wave crest and wave trough act, which makes the anti-sliding stability and anti-overturning stability safety factors in the "Design Specification for Seawalls" can only be calculated under the instantaneous action of the wave crest and wave trough, and cannot consider the cumulative action under the entire wave period, and cannot obtain a comprehensive evaluation of stability safety. The present invention is more comprehensive than the specification; furthermore, the above calculation of wave forces in the present invention uses a wave dynamic numerical model (see the cumulative average anti-sliding stability safety factor within a single wave period below , and the cumulative average anti-overturning stability safety factor within a single wave period ), based on nonlinear wave theory, can calculate the force time history of the whole process of wave action, and has the ability to accurately calculate wave nonlinear action loads such as wave breaking, slamming, overtopping, eddy current and water-gas mixing on the combined seawall. However, the "Hydrological Specifications for Ports and Waterways" only divides the wave states of vertical wall buildings on the exposed and concealed foundations into three types: standing waves, far-breaking waves and near-breaking waves, and gives the calculation methods of wave pressure on the wall, total horizontal wave force and wave buoyancy on the bottom of the wall respectively. The specification targets conventional seawalls and revetments, and is based on the empirical formula derived from linear wave theory and experimental data. There is no theoretical formula or specification to follow for the calculation of wave forces on this new type of combined seawall, as well as wave loads, wave climbing and overtopping caused by extreme nonlinear wave actions such as storm surges and tsunamis, and its applicability is not clear. The present invention is aimed at the complex types of combined seawalls. The wave force calculation method adopted by the present invention can accurately calculate the nonlinear wave forces of waves such as wave breaking, slamming, overtopping, eddy current and water-gas mixing when disasters such as storm surges and tsunamis occur, which is more accurate than that in the specifications.

[0189] Although the prior art discloses:

[0190] ;

[0191] In the formula, is the friction coefficient between the interface of the wave-breaking dike and the sloped seawall, is the slope angle of the sloped seawall. To eliminate the gravity of the wave dam, are the horizontal and vertical components of the load on the surface of the wave-breaking dike, It is the safety factor of instantaneous anti-slip stability.

[0192] However, the physical meaning of the calculation formula in the prior art is unclear, and there are errors. The instantaneous minimum anti-slip stability safety factor in the present invention is After correction, the prediction data is more accurate. The technical problem targeted by the formula of the prior art is the cross-sectional type comparison of the wave-breaking dike, which is suitable for academic research. The technical problem targeted by the present invention is the stability assessment method and calculation system of the wave-breaking dike, which solves the technical problem of the stability assessment of the combined seawall and is suitable for engineering applications.

[0193] The instantaneous minimum anti-tilt stability safety factor Calculated by the following formula:

[0194] ;

[0195] It is understandable that although the prior art papers disclose:

[0196] ;

[0197] In the formula, is the self - gravity moment of the wave - dissipating breakwater, is the internal force moment at the connection between the wave - dissipating breakwater and the sloping seawall, is the moment acting on the surface of the wave - dissipating breakwater due to wave loads, The internal force moment at the connection between the wave - dissipating breakwater and the sloping seawall, is the safety factor required by the specification. is the safety factor of instantaneous anti - overturning stability.

[0198] However, the application of the present invention is different from the prior art. In the prior art, the minimum value of the formula calculation result is taken as the judgment standard for instantaneous anti - overturning stability when comparing with the present invention, and the predicted data is more accurate.

[0199] The present invention innovatively proposes that the cumulative average anti - sliding stability safety factor within a single - wave period is calculated by the following formula:

[0200] ;

[0201] The present invention innovatively proposes that the cumulative average anti - overturning stability safety factor within a single - wave period is calculated by the following formula:

[0202] .

[0203] The newly proposed coefficient can consider the cumulative effect under the entire wave period and obtain a comprehensive evaluation of the stability and safety of the wave - dissipating breakwater.

[0204] Example 2, as Figure 4 shown, the present invention provides a wave - dissipating breakwater stability performance evaluation system for a combined seawall, including:

[0205] A hydrological module 1, which integrates the hydrological data of the area where the combined seawall is located, obtains the hydrological data of the area where the combined seawall is located, and has representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of incident waves;

[0206] A seawall structure cross - section data module 2, which is used to obtain the combined seawall structure cross - section data, including the height, slope and facing structure data of the sloping seawall in the combined seawall, and the position, front - slope gradient, height, crest width, rear - slope gradient and facing structure data of the wave - dissipating breakwater;

[0207] A wave dynamic numerical model module 3, which is used to establish a numerical model for calculating wave hydrodynamic elements of the target combined seawall by using the preset Navier - Stokes equation and THINC algorithm, and is used to solve the wave pressure and loads acting on the wave - dissipating breakwater;

[0208] The wave load index determination module 4 is used to simulate the wave run-up on the embankment body and the overtopping on the crest of the wave-dissipating embankment of the target combined seawall by using a wave dynamic numerical model according to the hydrological data of the area where the combined seawall is located and the cross-section data of the seawall structure, calculate the wave force and wave moment of the wave-dissipating embankment, and determine the wave load index;

[0209] The wave-dissipating embankment structure index determination module 5 is used to calculate the self-weight of the wave-dissipating embankment of the target combined seawall, the connection force between the wave-dissipating embankment and the slope seawall, and the moment thereof on the overturning fulcrum according to the hydrological data and the cross-section data of the seawall structure, obtain the gravity and gravity moment of the wave-dissipating embankment, and determine the wave-dissipating embankment structure index;

[0210] The stability evaluation calculation module 6 is used to calculate the anti-overturning stability and anti-sliding stability safety factors according to the wave load index and the wave-dissipating embankment structure index, compare with the safety factor, and form a stability safety evaluation result.

[0211] Embodiment 3, as another possible implementation manner of the present invention, the method for evaluating the stability performance of the wave-dissipating embankment of the combined seawall provided by the embodiment of the present invention includes:

[0212] Obtain the cross-section data of the combined seawall structure and the hydrological data of the area where the combined seawall is located.

[0213] Use the hydrological data of the area where the combined seawall is located, the cross-section data of the seawall structure and the wave dynamic numerical model to simulate the wave run-up on the embankment body and the overtopping on the crest of the wave-dissipating embankment of the target combined seawall, obtain the wave force and wave moment of the wave-dissipating embankment, and determine the wave load index;

[0214] Use the hydrological data and the cross-section data of the seawall structure to calculate the self-weight of the wave-dissipating embankment of the target combined seawall and the moment of the gravity on the overturning fulcrum, obtain the gravity and gravity moment of the wave-dissipating embankment, and determine the wave-dissipating embankment structure index;

[0215] Use the wave load index and the wave-dissipating embankment structure index to calculate the anti-overturning stability and anti-sliding stability safety factors, compare with the safety factor in the "Design Code for Seawall Engineering", and form a stability safety evaluation result.

[0216] Wherein, the hydrological data of the area where the combined seawall is located includes representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of the incident wave;

[0217] Wherein, the cross-section data of the seawall structure includes the height, slope and facing structure data of the slope seawall in the combined seawall, and the position, front slope, height, crest width, rear slope and facing structure data of the wave-dissipating embankment, and its cross-section schematic diagram is as Figure 1 shown;

[0218] Among them, for the wave dynamic numerical model, a numerical model for calculating wave hydrodynamic elements of the target combined seawall is established by using a preset Navier-Stokes equation, which is used to solve the wave pressure and load acting on the wave-dissipating breakwater. The schematic diagram of the load on the wave-dissipating breakwater is as Figure 3 shown.

[0219] To further illustrate the relevant effects of the embodiments of the present invention, the following experiments are carried out.

[0220] The present invention selects a scaled physical model of a certain actual combined seawall project for analysis and calculation, and uses the results of the model test to verify the accuracy of the wave dynamic numerical model. According to the actual engineering conditions and test conditions, the model scale is determined to be 36. The method for evaluating the stability performance of the wave-dissipating breakwater of the combined seawall provided by the embodiments of the present invention includes:

[0221] Step 1, obtain the hydrological data of the area where the combined seawall is located, including representative wave hydrological characteristic values, including water depth, tidal level, tidal current velocity, wave height and period of the incident wave;

[0222] Specifically, the actual water depth is 7.92 m, the model water depth d = 0.22 m, the tidal level and tidal current velocity are not considered, and the incident wave adopted is an isolated wave to simulate strong nonlinear waves such as storm surges and tsunamis. The actual wave height is 2.2968 m, and the model wave height H = 0.0638 m.

[0223] Step 2, obtain the cross-section data of the seawall structure, including the height, slope and facing structure data of the slope-type seawall in the combined seawall, as well as the position, front slope, height, crest width, rear slope and facing structure data of the wave-dissipating breakwater. The cross-section schematic diagram is as Figure 1 shown;

[0224] Specifically, the slope of the slope-type seawall is 1:20, the actual height is 14.4 m, the model height is 0.4 m, the facing structure adopts block stone facing blocks, the wave-dissipating breakwater is located at a horizontal distance of 129.6 m from the slope angle of the slope-type seawall (the model value is 3.6 m), the front slope is 1:4, the height from the crest to the front slope angle is 2.736 m (the model value is 0.076 m), the crest width is 1.728 m (the model value is 0.048 m), the rear slope is 1:1.8, the facing structure adopts integral concrete casting, no connecting anchor bolts are provided between the wave-dissipating breakwater and the slope-type seawall, the wave-dissipating breakwater is directly placed on the slope-type seawall, and according to the experiment, the friction coefficient between the contact surfaces is 0.6.

[0225] Step 3, establish a wave dynamic numerical model, and establish a numerical model for calculating wave hydrodynamic elements of the target combined seawall by using a preset Navier-Stokes equation and a preset THINC algorithm, which is used to solve the wave pressure and load acting on the wave-dissipating breakwater. The schematic diagram of the load is asFigure 3 as shown

[0226] The preset Navier - Stokes equation is as follows:

[0227] ;

[0228] ;

[0229] In the formula, is the coordinate of the Cartesian coordinate system, is the component of the velocity along each coordinate, is the viscous stress, ; , for an incompressible fluid ; is the body force.

[0230] The THINC algorithm is a numerical algorithm for tracking the free interface of waves. The one - dimensional formula of its volume function is as follows:

[0231] ;

[0232] In the formula, is the time, is the volume function occupied by the fluid in a grid cell, is the velocity of the flow field, represents partial differentiation.

[0233] Integrating the above formula within the grid cell and the time interval yields:

[0234] ;

[0235] In the formula, is a time interval, , is the length of a grid cell, , is the average value of the numerical solution of the grid cell at time

[0236] ;

[0237] represents the flux through the cell boundary and the expression is:

[0238] ;

[0239] The piecewise modified hyperbolic tangent function is adopted to estimate the distribution of the volume function within the computational grid cells:

[0240] ;

[0241] In the formula, the parameter affects the quality of the numerical solution, the midpoint of the hyperbolic tangent function's jump conversion is solved by the following formula:

[0242] ;

[0243] The parameter ensures that the boundaries of the hyperbolic tangent function within the grid cells are :

[0244] ;

[0245] It can also be seen from the formula that the interpolation function within the grid cell is determined by the larger function value in the adjacent grid cells, and thus has the effect of anti-numerical diffusion, eliminating the blurring of the free surface.

[0246] The parameter defines the direction of the slope of the hyperbolic tangent function:

[0247] ;

[0248] The parameter is used to control the steepness of the hyperbolic tangent function's jump, taking .

[0249] After the function is determined, the flux on the cell boundary is expressed as:

[0250] ;

[0251] The definitions of each variable are as shown in the schematic diagram of the THINC format provided in Figure 5 . The shaded part represents the value of when .

[0252] Step 4: According to the hydrological data and the cross-sectional data of the seawall structure in the area where the combined seawall is located, use the wave dynamic numerical model to simulate the wave run-up on the seawall body and the overtopping on the top of the wave dissipating seawall of the target combined seawall, calculate the wave force and wave moment of the wave dissipating seawall, and determine the wave load index;

[0253] Specifically, based on the hydrological data of the area where the composite seawall is located and the cross-sectional data of the seawall structure, a wave dynamic numerical model was used to model and numerically simulate the target composite seawall. The free surface spatial distribution of the overtopping flow on the wave-dissipating dike calculated by the wave dynamic numerical model at different times, the time history of the pressure at each measuring point on the wave-dissipating dike, and the time history of the total horizontal and vertical forces on the wave-facing and wave-backing surfaces of the wave-dissipating dike were calculated. It can be seen from the calculation that the established wave dynamic numerical model can accurately simulate the wave run-up on the seawall body and the overtopping of the wave-dissipating dike crest, and calculate the wave force pressure and total force on the wave-dissipating dike.

[0254] Calculate the wave forces and wave moments of the wave-dissipating dike, and determine the wave load indexes as follows:

[0255] (1) Instantaneous wave force and moment indexes;

[0256] , the time history of the horizontal component of the instantaneous load value of the wave acting on the wave-facing, top, and wave-backing surfaces of the wave-dissipating dike, , the time history curve calculated by the wave dynamic numerical model is as Figure 6 shown.

[0257] , the time history of the vertical component of the instantaneous load value of the wave acting on the wave-facing, top, and wave-backing surfaces of the wave-dissipating dike, , the time history curve calculated by the wave dynamic numerical model is as Figure 7 shown.

[0258] , the time history of the uplift force of the wave acting on the bottom surface of the wave-dissipating dike, , the time history curve calculated by the wave dynamic numerical model is as Figure 8 shown.

[0259] , the anti-sliding effect force of the wave load along the slope of the sloping seawall, with the upward direction being positive, , its time history curve is as Figure 9 shown.

[0260] , the anti-sliding effect force of the wave load along the slope of the sloping seawall, , its time history curve is as Figure 10 shown.

[0261] , the time history of the moment of the wave load acting on the wave-facing, top, and wave-backing surfaces of the wave-dissipating dike, , the time history curve calculated by the wave dynamic numerical model is as Figure 11 shown.

[0262] The time history of the moment of the wave floating uplift force acting on the bottom surface of the wave-dissipating dike The time history curve calculated by the wave dynamic numerical model is as Figure 12 shown.

[0263] (2) Cumulative wave impulse and impulse moment indexes within a single wave period;

[0264] The wave period, for solitary waves such as tsunamis: .

[0265] The anti-sliding force impulse of the wave load within a single wave period The time history curve calculated by the wave dynamic numerical model is as Figure 13 shown.

[0266] The sliding force impulse of the wave load within a single wave period The time history curve calculated by the wave dynamic numerical model is as Figure 14 shown.

[0267] The overturning impulse moment of the wave load within a single wave period The time history curve calculated by the wave dynamic numerical model is as Figure 15 shown.

[0268] Step 5: According to the hydrological data and the cross-sectional data of the seawall structure, calculate the self-weight of the wave-dissipating dike of the target combined seawall, the connection force between the wave-dissipating dike and the slope seawall, and the moment thereof on the overturning fulcrum, obtain the gravity and gravity moment of the wave-dissipating dike, and determine the structural indexes of the wave-dissipating dike;

[0269] Specifically, the structural indexes of the wave-dissipating dike include instantaneous gravity and moment indexes and cumulative gravity impulse and impulse moment indexes within a single wave period.

[0270] 1) Instantaneous gravity and moment indexes:

[0271] The self-weight of the wave-dissipating dike ;

[0272] The anti-sliding force of the self-weight of the wave-dissipating dike ;

[0273] The sliding force of the self-weight of the wave-dissipating dike ;

[0274] The self-weight moment of the wave-dissipating dike ;

[0275] The internal force at the connection between the wave-dissipating breakwater and the sloping seawall is taken as 0;

[0276] , the internal force moment at the connection between the wave-dissipating breakwater and the sloping seawall, .

[0277] 2) Cumulative gravity impulse and impulse moment indices within a single wave period:

[0278] , the cumulative anti-sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period, = 820.13 .

[0279] , the cumulative sliding impulse of the self-weight of the wave-dissipating breakwater within a single wave period, .

[0280] , the cumulative anti-overturning impulse moment of the self-weight of the wave-dissipating breakwater within a single wave period, .

[0281] , the cumulative internal force impulse moment at the connection between the wave-dissipating breakwater and the sloping seawall within a single wave period, .

[0282] Step 6, according to the wave load index and the wave-dissipating breakwater structure index, calculate the anti-overturning stability and anti-sliding stability safety factors, and compare them with the safety factors in the "Design Code for Seawall Engineering" to form the stability safety assessment result.

[0283] Specifically, the anti-overturning stability and anti-sliding stability safety factors include the instantaneous minimum anti-overturning stability and anti-sliding stability safety factors and the cumulative average anti-overturning stability and anti-sliding stability safety factors within a single wave period;

[0284] (i) Instantaneous minimum anti-sliding stability safety factor and anti-overturning stability safety factor;

[0285] The instantaneous anti-sliding stability safety factor is calculated based on the instantaneous wave load index and the gravity index, and its time history curve of the instantaneous minimum anti-sliding stability safety factor is as Figure 16 shown. The time history curve of the instantaneous minimum anti-overturning stability safety factor is as Figure 17 shown;

[0286] The instantaneous minimum anti-sliding stability safety factor is calculated by the following formula:

[0287] ;

[0288] Its minimum value is , and the occurrence time is .

[0289] The instantaneous minimum anti-overturning stability safety factor is calculated by the following formula:

[0290] ;

[0291] Its minimum value is , and the occurrence time is .

[0292] In the "Code for Design of Seawall Engineering", for the retaining wall and wave-dissipating wall of Class 1 seawall projects, the safety factor for anti-sliding stability shall not be less than 1.35, and the safety factor for anti-overturning stability of the retaining wall and wave-dissipating wall of Class 1 seawall projects is specified not to be less than 1.6. Thus, it can be seen that its instantaneous anti-overturning stability is the most dangerous.

[0293] (ii) Cumulative average anti-overturning stability and anti-sliding stability safety factors within a single wave period;

[0294] The cumulative average anti-sliding stability safety factor within a single wave period is calculated based on the cumulative wave impulse and impulse moment indexes within a single wave period. The time history curve of the cumulative average anti-sliding stability safety factor within a single wave period is as Figure 18 shown. The time history curve of the cumulative average anti-overturning stability safety factor within a single wave period is as Figure 19 shown;

[0295] The cumulative average anti-sliding stability safety factor within the single wave period described above is calculated by the following formula:

[0296] ;

[0297] As time goes by, its safety factor gradually increases, and the minimum value is , and the occurrence time is .

[0298] The cumulative average anti-overturning stability safety factor within the single wave period described above is calculated by the following formula:

[0299] ;

[0300] As time goes by, its safety factor first decreases and then increases, and the minimum value is , and the occurrence time is .

[0301] Thus, it can be seen that its cumulative average anti-overturning stability within a single wave period is the most dangerous.

[0302] As described above, only the relatively preferred specific embodiments of the present invention are provided, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention, any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A method for evaluating the stability performance of a wave-breaking dam of a combined seawall, characterized in that: The method includes: S1. Establish a wave dynamic numerical model, and use the preset Navier-Stokes equations and THINC algorithm to establish a numerical model for calculating wave hydrodynamic elements for the target combined seawall, so as to solve the wave pressure and load acting on the wave-breaking dike; S2. Based on the hydrological data of the area where the combined seawall is located and the cross-section data of the seawall structure, a wave dynamic numerical model is used to simulate the wave climbing of the target combined seawall and the wave overtopping of the wave-breaking embankment, and the wave force and wave moment of the wave-breaking embankment are calculated to determine the wave load index; S3. Calculate the gravity of the wave-breaking dike of the target combined seawall, the connection force between the wave-breaking dike and the sloped seawall, and the moment of force on the overturning fulcrum based on the hydrological data and the seawall structure section data, obtain the gravity and gravity moment of the wave-breaking dike, and determine the structural index of the wave-breaking dike; S4. Calculate the safety factors of anti-tilting stability and anti-sliding stability based on the wave load index and wave-breaking dike structure index, and compare them with the safety factors to form a stability safety assessment result; In step S2, wave load indices are determined, including: instantaneous wave force and moment indices, cumulative wave impulse and impulse moment indices within a single wave cycle; The instantaneous wave force and moment index include: the horizontal component force F of the load on the three surfaces of the wave-breaking dike, namely, the wave-facing surface, the top surface and the wave-receiving surface; wx The vertical component of the load F of the wave acting on the wave-facing, top and back surfaces of the wave-breaking dike is wz , the buoyancy force F of the wave acting on the bottom of the wave-breaking dike u The load moment M of the wave acting on the wave-facing surface, top surface and back surface of the wave-breaking dike is w , the buoyancy moment M of the wave acting on the bottom of the wave-breaking dike u , the anti-sliding effect force F of wave load along the slope of the sloped seawall w抗 , the anti-sliding effect force F of wave load along the slope of the sloped seawall w滑 ; The cumulative wave impulse and impulse moment index within a single wave cycle include: the anti-slip force impulse I of the wave load within a single wave cycle w抗-T , the sliding force impulse I of the wave load in a single wave cycle w滑-T , the overturning impulse moment L of the wave load in a single wave cycle w倾-T ; The horizontal component of the load F of the wave acting on the wave-facing, top and back surfaces of the wave-breaking dike wx Calculated by the wave dynamic numerical model, the expression is: Where A is the surface of the seawall facing the waves, the top surface, and the back surface of the waves, p is the wave pressure acting on each point on the seawall, and n is k is the unit normal vector perpendicular to the wave-facing, top and back-wave surfaces of the seawall, δ ik is the Dirac delta function, A x is the projection of the surface area of ​​the seawall's wave-facing, top and wave-repelling surfaces in the x direction, and d is the calculus; The vertical component of the load F of the wave acting on the wave-facing, top and back surfaces of the wave-breaking dike wz , calculated by the wave dynamic numerical model, the expression is: In the formula, A z It is the projection of the surface area of ​​the seawall facing the wave, top surface and back wave surface in the z direction; The buoyancy force F exerted by waves on the bottom of the wave-breaking dike u , the expression is: F u =0.5(P 1b +P rb )B Where P 1b is the wave pressure time history at the bottom corner of the wave-facing surface of the wave-breaking dike, P rb is the wave pressure time history at the bottom corner of the back wave surface of the wave-breaking dam, B is the distance between the two bottom corners of the wave-breaking dam, and F u What is being solved is the force at each moment; The load moment M of the wave acting on the wave-breaking dike's wave-facing surface, top surface, and wave-receiving surface w , calculated by the wave dynamic numerical model, the expression is: In the formula, is the arm of force from the wave load force acting point at a certain point on the surface of the wave-breaking dike to the overturning support point on the bottom surface of the wave-breaking dike, and A is the surface of the wave-facing, top and back surfaces of the seawall; The buoyancy moment M of the wave acting on the bottom of the wave-breaking dike u , the expression is: Where, d u It is the lever arm from the point of action of the resultant wave buoyancy force to the overturning fulcrum on the bottom surface of the wave-breaking dike; The anti-sliding effect force F of wave load along the slope of the seawall w抗 , the expression is: F w抗 =F wz cosθ+F u -F wx sinθ Where θ is the slope angle of the sloped seawall; The anti-sliding effect force F of wave load along the slope of the seawall w滑 , the expression is: F w滑 =F wx cosθ+F wz sinθ。 2. The method for evaluating the stability performance of the wave-breaking dam of a combined seawall according to claim 1, characterized in that: Before step S1, you need to do: Obtain hydrological data of the area where the combined seawall is located, with representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of incident waves; The cross-sectional data of the combined seawall structure are obtained, including the height, slope and face protection structure data of the sloped seawall in the combined seawall, as well as the location, front slope slope, height, crest width, rear slope slope and face protection structure data of the wave-breaking dike.

3. The method for evaluating the stability performance of the wave-breaking dam of a combined seawall according to claim 1, characterized in that: The anti-sliding force impulse I of wave load in a single wave cycle w抗-T , the expression is: The sliding force impulse L of wave load in a single wave cycle w滑-T , the expression is: The overturning impulse moment L of wave load in a single wave cycle w倾-T , the expression is: Where T is the wave period. For a tsunami solitary wave β is the attenuation coefficient, H is the height of the solitary wave, d is the still water depth, and c is the speed of the solitary wave.

4. The method for evaluating the stability performance of a wave-breaking dike of a combined seawall according to claim 1, characterized in that: In step S3, the wave-breaking dike structure indicators include: instantaneous gravity and moment indicators, cumulative gravity impulse and impulse moment indicators within a single wave cycle; The instantaneous gravity and moment indicators include: the wave-breaking dam’s own gravity G, the internal force at the connection between the wave-breaking dam and the sloped seawall, and the wave-breaking dam’s own gravity moment M G , the internal force moment M at the connection between the wave-breaking dike and the sloped seawall 连 , the anti-sliding force F of the wave-breaking dam's own gravity G抗 , the sliding force F of the wave-breaking dam's own gravity G滑 ; The cumulative gravity impulse and impulse moment index within a single wave cycle include: the cumulative gravity anti-sliding impulse of the wave-breaking dam itself within a single wave cycle I G抗-T , the accumulated gravitational sliding impulse of the wave-breaking dam itself in a single wave cycle I G滑-T , the cumulative anti-overturning impulse moment L of the wave-breaking dam's own gravity in a single wave cycle G抗-T .

5. The method for evaluating the stability performance of the wave-breaking dam of a combined seawall according to claim 4 is characterized in that: The gravity moment of the wave-breaking dam itself M G , the expression is: M G =G·d G Where, d G It is the arm of force from the point of action of the combined force of the wave-breaking dam's own gravity to the overturning fulcrum of the bottom surface of the wave-breaking dam; Internal force moment M at the connection between wave-breaking dike and sloped seawall 连 , determined according to the connection method of the two. If the connection method is direct placement, the moment at the connection is zero. If the connection method is anchor bolt anchoring, the maximum moment expression is: M 连 =F 锚 ·d 锚 ; In the formula, F 锚 is the shear load borne by the anchor bolts at the connection, d 锚 It is the arm of force from the shear load action point of the anchor bolt at the connection to the overturning support point on the bottom surface of the wave-breaking dike; The anti-sliding force F of the wave-breaking dam's own gravity G抗 , the expression is: F G抗 =Gcosθ Where θ is the slope angle of the sloped seawall; The sliding force F of the wave-breaking dam's own gravity G滑 , the expression is: F G滑 =-Gcosθ The accumulated anti-sliding impulse of the wave-breaking dike itself in a single wave cycle I G抗-T , the expression is: I G抗-T =Gcosθ·T Where T is the wave period; The accumulated gravitational sliding impulse of the wave-breaking dike itself in a single wave cycle I G滑-T , the expression is: I G滑-T =Gsinθ·T The cumulative anti-overturning impulse moment L of the wave-breaking dike's own gravity in a single wave cycle G抗-T , the expression is: L G抗-T =M G ·T The cumulative shear load and overturning impulse moment L at the connection within a single wave cycle 连抗-T , the expression is: L 连抗-T =M 连 ·T。 6. The method for evaluating the stability performance of the wave-breaking dam of a combined seawall according to claim 4, characterized in that: In step S4, the anti-sliding stability safety factor is expressed as: In the formula, K s-max is the anti-sliding stability safety factor, max() is the maximum value of the anti-sliding stability safety within the time history range, and f is the friction coefficient between the wave-breaking dike and the sloped seawall connection interface.

7. The method for evaluating the stability performance of the wave-breaking dam of a combined seawall according to claim 6, characterized in that: The instantaneous maximum value of the anti-sliding stability safety factor is: Cumulative average anti-sliding stability safety factor K within a single wave cycle s-T Calculated by the following formula: Cumulative average anti-overturning stability safety factor K within a single wave cycle r-T Calculated by the following formula: Where, L 连抗-T is the cumulative shear load and overturning impulse moment of the connection within a single wave cycle.

8. A wave-breaking dike stability performance evaluation system for a combined seawall, characterized in that: The system is implemented by the method for evaluating the stability performance of the wave-breaking dike of the combined seawall according to any one of claims 1 to 7, and the system comprises: A hydrological module (1), which integrates hydrological data of the area where the combined seawall is located, obtains hydrological data of the area where the combined seawall is located, and has representative wave hydrological characteristic values, including water depth, tide level, tidal current velocity, wave height and period of incident waves; The seawall structure section data module (2) is used to obtain the combined seawall structure section data, including the height, slope and face protection structure data of the sloped seawall in the combined seawall, and the location, front slope, height, embankment top width, rear slope and face protection structure data of the wave-breaking embankment; A wave dynamic numerical model module (3) is used to establish a numerical model for calculating wave hydrodynamic elements for the target combined seawall using the preset Navier-Stokes equations and THINC algorithm, and is used to solve the wave pressure and load acting on the wave-breaking dike; The wave load index determination module (4) is used to perform wave climbing simulation on the target combined seawall and wave overtopping simulation on the top of the wave-breaking embankment based on the hydrological data of the area where the combined seawall is located and the cross-section data of the seawall structure, using a wave dynamic numerical model, to calculate the wave force and wave moment of the wave-breaking embankment and determine the wave load index; The wave-breaking dike structure index determination module (5) is used to calculate the self-gravity of the wave-breaking dike of the target combined seawall, the connection force between the wave-breaking dike and the sloped seawall, and the moment of force on the overturning support point based on the hydrological data and the seawall structure section data, so as to obtain the gravity and gravity moment of the wave-breaking dike and determine the wave-breaking dike structure index; The stability evaluation calculation module (6) is used to calculate the safety factor of anti-tilting stability and anti-sliding stability according to the wave load index and the wave-breaking dike structure index, and compare them with the safety factor to form a stability safety evaluation result.

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