Water pool aseismic design method considering dynamic water load

Abstract

The invention discloses a pool aseismic design method considering dynamic water load. Comprising the following steps: firstly, inputting geometric dimension parameters and seismic oscillation parameters of a pool; secondly, calculating dynamic parameters, pool wall rigidity, response spectrum coefficients and the like; thirdly, respectively calculating the bottom shearing force of the self-earthquake of the pool wall, the bottom shearing force of the pulse water pressure to the pool wall, the bottom shearing force of the convection water pressure to the pool wall and the bottom shearing force of the vertical earthquake water pressure to the pool wall under the earthquake action, and carrying out SRSS combination to obtain the total bottom shearing force; and finally, according to the calculated bottom shearing force multiplied by the previously calculated acting force centroid, the bending moment to the bottom of the pool wall under each acting force is obtained, all the bending moments SRSS are combined to obtain the unbalanced bending moment of the whole pool under the earthquake force, and the unbalanced bending moment is distributed to a bottom plate and transmitted to a foundation. Pulse water pressure and convection water pressure of the pool are converted into water pressure through a formula and act on the pool wall.

Description

Technical Field

[0001] This invention relates to a method for seismic design of water tanks that takes into account dynamic water loads. Background Technology

[0002] National standards for seismic design of water tanks with dynamic water loads are limited. Domestic water tank designs widely rely on static water loads for calculations, lacking design considerations for dynamic loads such as the impulse force, convection force, vertical seismic water pressure, and horizontal self-vibration pressure generated by the fluid inside the tank under seismic loads. For some water tanks located entirely above ground with a large volume of water, the dynamic water loads under seismic action are particularly significant. The water inside the tank experiences violent swaying under both horizontal and vertical seismic forces, potentially breaching the tank walls and damaging the tank. Therefore, in areas with high seismic fortification intensity, it is necessary to calculate the dynamic water loads of water tanks under seismic action. Summary of the Invention

[0003] To address the above problems, this invention provides a method for designing water tanks to withstand seismic water loads.

[0004] To achieve the above objectives, the present invention provides a method for seismic design of water tanks considering dynamic water loads, comprising the following steps: First, input the geometric dimensions and seismic parameters of the water tank; Secondly, calculate the dynamic parameters, including the pool wall stiffness, response spectrum coefficient, effective mass coefficient, mass of the dynamic water involved, wall mass, and centroid of the point of application of the dynamic water load. Next, the base shear force of the pool wall under seismic action, the base shear force of the pool wall under pulsed water pressure, the base shear force of the pool wall under flowing water pressure, and the base shear force of the pool wall under vertical seismic water pressure are calculated separately. These are then combined using SRSS to obtain the total base shear force. This total base shear force is then compared with the base shear force obtained from the response spectrum in the model, and the larger value is used for design. Finally, by multiplying the calculated bottom shear force by the previously calculated centroid of the force, the bending moment at the bottom of the pool wall under each force is obtained. All bending moments SRSS are combined to obtain the unbalanced bending moment of the entire pool under seismic force, and the unbalanced bending moment is distributed to the bottom plate and transferred to the foundation. The pulse water pressure and convective water pressure of the pool are converted into water pressure by formula and act on the pool wall.

[0005] Furthermore, the earthquake parameters include regional coefficients, soil coefficients, source type, response spectrum adjustment coefficients, peak ground acceleration, near-field coefficients, horizontal seismic coefficients, vertical seismic coefficients, and site natural period. Attached Figure Description

[0006] Figure 1 This is an input diagram of the geometric dimensions and seismic parameters of the water tank in this invention; Figure 2This is a calculation diagram of the dynamic parameters, water tank wall stiffness, response spectrum coefficient, effective mass coefficient, dynamic water participation mass, wall mass, and centroid of the dynamic water load application point of the present invention. Figure 3 The diagram shows the calculation of the bottom shear force of the pool wall under natural vibration, the bottom shear force of the pool wall under pulsed water pressure, the bottom shear force of the pool wall under convective water pressure, and the bottom shear force of the pool wall under vertical seismic water pressure. Figure 4 This is a calculation diagram of the total unbalanced bending moment at the bottom of the pool, the pulse water pressure acting on the pool wall, and the convective water pressure of the present invention; Figure 5 This diagram illustrates the pressure exerted on the pool wall by the vertical seismic water pressure qh, the self-vibration pressure pw of the pool wall, the pulse water pressure pi, and the convective water pressure pc. Detailed Implementation

[0007] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0008] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0009] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0010] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0011] Example 1 The structural calculations for this project were performed using Midas Gen building structure analysis and design software.

[0012] like Figure 1As shown, input the geometric parameters of an open water tank with a length of 10m, a width of 10m, and a height of 5m. The tank wall thickness is 0.5m, the full water height is 5m, and it is a fully above-ground water tank. Input the self-weight of concrete, the self-weight of water, the elastic modulus of concrete, and the design value of concrete compressive strength. Then input the seismic parameters, including regional coefficients, soil coefficients, source type, response spectrum adjustment coefficient, peak ground acceleration, near-field coefficients, seismic horizontal coefficients, seismic vertical coefficients, and site natural period.

[0013] like Figure 2 As shown, based on the input geometric and seismic parameters of the pool, the dynamic mass of the wall is mw = 6166.21 kg / m, the dynamic mass of the water is mi = 13557.91 kg / m, and the centroid height is h = 2.07 m. The pool wall stiffness is k = 99071438.77 N / sq.m, the natural period of the pool wall is Ti = 0.09 sec, and the natural period of the water is Tc = 3.72 sec. The pool wall response spectrum coefficient is Ci = 1.10, and the natural period of the water is Cc = 0.19. The effective mass coefficient is ε = 0.7. The weight of the water involved in the pulse is Wi = 2660 kN, the weight of the water involved in the convection is Wc = 2379 kN, the mass of a single pool wall is Ww' = 600 kN, the total mass of the pool wall is Ww = 2400 kN, the height of the pulsed water is hi = 1.88 m, and the height of the convection water is hc = 2.92 m.

[0014] like Figure 3 As shown, according to Figure 1 and Figure 2 The input parameters allow us to calculate the following under seismic loading conditions: the bottom shear force of a single pool wall is Pw' = 288.67 kN, the total bottom shear force of the pool wall is Pw = 1154.67 kN, the pulse water pressure is Pi = 1279.79 kN, the convective water pressure is Pc = 396.69 kN, and the vertical seismic water pressure is Ph = 305.56 kN. The total bottom shear force of a single pool wall using the SRSS combination is V = 1617.84 kN. The total bottom shear force V is compared with the bottom shear force V obtained from the response spectrum method calculated by the model, and the larger value is used for verification of the pool wall's shear bearing capacity. The formulas involved in the above calculations include:

[0015] like Figure 4 As shown, according to Figure 3 Multiply the calculated bottom shear force values ​​for each type by the corresponding force application height to obtain the bending moment for each type of force. Combine all bending moments using the SRSS method to obtain the unbalanced bending moment of the entire pool, M = 8165.87 kN·m. Apply this unbalanced bending moment to the pool bottom slab and verify the bending, shear, and foundation bearing capacities of the pool bottom slab. Figure 3The obtained pulse water pressure and convective water pressure are converted into pressure using the following formulas: Pulsed water pressure at the top piL = 223.96 kN / m (not divided by the pool wall width), pulsed water pressure at the bottom piU = 31.99 kN / m (not divided by the pool wall width), convective water pressure at the top pcL = 19.85 kN / m (not divided by the pool wall width), convective water pressure at the bottom pcU = 59.49 kN / m (not divided by the pool wall width). Then... Figure 5 The force is applied to the pool wall in the form of seismic force, and is used as part of the load combination specified in the code to verify the flexural bearing capacity of the pool wall.

[0016] The present invention has been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Many other changes and modifications made without departing from the concept and scope of the present invention should be considered within the scope of protection of the present invention.

[0017] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0018] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method of seismic design of a water tank considering hydrodynamic load, characterized by, The method comprises the following steps: First, input the geometric size parameters of the pool, ground motion parameters; Second, calculate the dynamic parameters, pool wall stiffness, response spectrum coefficient, effective mass coefficient, dynamic water participation mass, wall mass and action point centroid of dynamic water load calculation; Third, calculate the bottom shear force of the pool wall under the action of earthquake, the bottom shear force of the pool wall under the action of pulse water pressure, the bottom shear force of the pool wall under the action of convection water pressure, and the bottom shear force of the pool wall under the action of vertical earthquake water pressure, respectively, combine them by SRSS, obtain the total bottom shear force, and compare it with the bottom shear force obtained by the model response spectrum, adopt the larger value for design; Finally, multiply the calculated bottom shear force by the previously calculated action force centroid to obtain the bending moment on the pool wall bottom under the action of each force, combine all the bending moments by SRSS to obtain the unbalanced bending moment of the entire pool under the action of earthquake force, and distribute the unbalanced bending moment to the bottom plate and transfer it to the foundation; the pulse water pressure and convection water pressure of the pool are converted into water pressure by formula and act on the pool wall.

2. The method for seismic design of a pool considering hydrodynamic load according to claim 1, wherein, The seismic parameters include regional coefficient, soil coefficient, source type, response spectrum adjustment coefficient, site peak acceleration, near-field coefficient, seismic horizontal coefficient, seismic vertical coefficient and site self-seismic period.

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