Design method of PEC vertical component splicing joint

Abstract

The invention relates to the field of building structure design, in particular to a design method of a PEC vertical component splicing node, which comprises the following steps of: firstly, constructing a pouring-free PEC vertical component splicing node, drawing a node section, preliminarily determining the sizes of a side plate, a transverse partition plate and a stiffening plate according to a rigidity enveloping principle; the method comprises the following steps: determining the initial size of a node area, checking the rigidity, strength, stability and plate stress of the node area and the component area, adjusting the initial size according to a checking result to ensure that the checking result of the node area is not lower than that of the component area, finally rechecking the determined size according to a standard requirement, and taking a value according to a standard as a final determined size. According to the method, the correctness of the splicing node force transmission hypothesis is analyzed through finite element modeling, the structural system model is constructed, calculation and comparison of indexes are conducted on the structural system model and a common structural model in the prior art, it is ensured that the results of the structural system model and the common structural model are kept consistent, and therefore the PEC vertical component splicing node meeting the design requirement can be obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building structure design, and particularly relates to a design method of a PEC vertical component splicing joint. BACKGROUND

[0002] Partially encased steel-concrete composite structure (PEC structure for short) is an important structure type in the development of fabricated building industry, and is built by means of factory prefabrication and on-site rapid assembly. The PEC vertical component is usually composed of steel, steel bars and concrete. In the traditional construction, the splicing method of the PEC vertical component is as follows: the upper and lower spliced PEC vertical components are butt-jointed and then welded on site, and then the concrete is cast on site in the joint area. The traditional construction method has the problems of wet work on site, difficulty in controlling the quality of post-cast concrete, complex on-site welding process of steel bars in the joint area, and influence of post-cast concrete section maintenance on construction period. Therefore, various splicing joints without casting are proposed to replace the traditional splicing joint. However, there is still a lack of reliable design method to guide the design of the splicing joint without casting of the PEC vertical component. In view of this, the present application is born. SUMMARY

[0003] The present application discloses a design method of a splicing joint without casting of a PEC vertical component, which is implemented by the following technical scheme:

[0004] The design method of the splicing joint of the PEC vertical component comprises the following steps:

[0005] Step 1): constructing the splicing joint of the PEC vertical component;

[0006] The splicing joint of the PEC vertical component comprises an upper PEC component, a lower PEC component and side plates. The upper PEC component and the lower PEC component each comprise flanges on both sides, a web connecting the flanges, longitudinal bars on both sides of the web, connecting rods perpendicular to the longitudinal bars on both sides of the web, a transverse partition plate connected perpendicularly to the web and the flanges, a stiffener plate connected perpendicularly to the transverse partition plate and the web, and concrete filled in the web on both sides with the transverse partition plate as a separation line. The bottom surface of the transverse partition plate in the upper PEC component is higher than the bottom surface of the flange of the upper PEC component, the top surface of the transverse partition plate in the lower PEC component is flush with the top surface of the flange of the lower PEC component, the flange of the upper PEC component is welded to the flange of the lower PEC component, two side plates are arranged at intervals between the transverse partition plate of the upper PEC component and the transverse partition plate of the lower PEC component, the side plates are parallel to the web, the positions of the side plates correspond to the positions of the longitudinal bars, the stiffener plate is fixed to the longitudinal bars, the top end of the side plate is welded to the bottom of the transverse partition plate of the upper PEC component, and the bottom end of the side plate is welded to the top of the transverse partition plate of the lower PEC component.

[0007] Step 2): According to the distance between the diaphragm of the upper PEC member and the diaphragm of the lower PEC member, and according to the inner retreat size of the side plate installation position, the thickness of the side plate is preliminarily determined, and the sectional shape of the node area of the PEC vertical member splicing node is drawn;

[0008] Step 3): Check whether the thickness of the side plate determined in step 2) satisfies the following conditions: the stiffness, strength and stability in the two principal axis directions of the node area are not lower than the stiffness, strength and stability in the two principal axis directions of the member area; if the above conditions are satisfied, step 4) is continued, if the above conditions are not satisfied, the thickness of the side plate is adjusted according to the checking result until the above conditions are satisfied;

[0009] Step 4): The height, thickness of the stiffening plate and the thickness of the diaphragm are preliminarily determined;

[0010] Step 5): Assume that the internal force transmission of the upper and lower PEC members of the PEC vertical member splicing node is as follows: the compressive stress of the concrete of the upper PEC member under the action of axial force and bending moment is transmitted to the two side plates through the inverted T-beam structure composed of the diaphragm and the stiffening plate, and then transmitted to the lower PEC member through the side plates, and the lower PEC member has the same stress mode as the upper PEC member, but the stress direction is opposite;

[0011] Based on the analysis result of the internal force transmission assumption, the strength of the stiffening plate and the diaphragm under the action of axial force and bending moment is checked to ensure that the stress does not exceed the steel strength design value, if the verification result meets the design requirements, step 6) is continued, if the design requirements are not met, the size of the stiffening plate and the diaphragm is adjusted according to the checking result until the stress requirement is met;

[0012] Step 6): Based on the size of the side plate, diaphragm and stiffening plate determined in steps 3) and 5), the size of the side plate, diaphragm and stiffening plate is valued according to the requirements of the pure steel member in the specification according to the seismic grade, and the valued result is taken as the finally determined size;

[0013] Step 7): A PEC vertical member splicing node model is constructed by using a finite element analysis software, based on the size of the side plate, diaphragm and stiffening plate determined in step 6), the stress distribution of the splicing node under the action of axial force, bending moment and shear force is calculated and analyzed, and the correctness of the internal force transmission assumption of the splicing node in step 5) is verified;

[0014] Step 8): According to the position of the PEC vertical member splicing joint in the floor, the structural design software is used to respectively establish the structural system model of the PEC vertical member splicing joint and the ordinary structure model in the prior art, the side plate, the diaphragm and the stiffener size determined in step 6) are respectively introduced into the two models, and then the indexes of the two models are calculated and compared, and the corresponding index calculation results of the two models are kept consistent.

[0015] Further, in the step 2), when the web bottom surface of the upper PEC member is flush with the flange bottom surface of the upper PEC member, the cross-sectional shape of the joint area is in the shape of III; when the web of the upper PEC member is arranged only on the upper part of the diaphragm, the cross-sectional shape of the joint area is in the shape of II.

[0016] Further, in the step 3), the side plate thickness checking needs to be calculated as follows:

[0017] 3.1): axial compression bearing capacity checking, to ensure that the axial compression bearing capacity of the joint area is greater than the axial compression bearing capacity of the PEC member area, the calculation formula is as follows:

[0018] N uj ≥N u

[0019] In the above formula, N uj represents the axial compression bearing capacity of the joint area section, N u represents the axial compression bearing capacity of the member area;

[0020] 3.2): compression-bending strength bearing capacity checking, to make the M-N curves of the two principal axes of the PEC member be within the envelope range of the M-N curves of the joint area, the calculation formula is as follows:

[0021] ρ u ≥ρ uj

[0022]

[0023] In the above formula, ρ uj represents the compression-bending stress ratio of the joint area section, ρ u represents the compression-bending stress ratio of the member area; N represents the axial force design value on the section; M x , M y represent the bending moment design value around the x-axis and the bending moment design value around the y-axis; N u represents the compression bearing capacity design value of the section; N mx , N my represent the characteristic axial forces for the x-axis and the y-axis; M ux , M uy represent the bending bearing capacity design values around the x-axis and around the y-axis; A nA denotes the net sectional area of steel member in the joint region; γ x x A denotes the sectional plastic development coefficient of the principal axis x, y; f denotes the design value of tensile and compressive strength of steel; W nx ny W denotes the net sectional modulus of x axis, y axis, respectively;

[0024] 3.3): the rigid envelope checking calculation of the joint region, the calculation formula is as follows:

[0025] E s I jx ≥E e I ex

[0026] E s I jy ≥E e I ey

[0027] E e I ex =E s I sx +E c I cx

[0028] E e I ey =E s I sy +E c I cy

[0029] In the above formula, E s denotes the elastic modulus of steel, I jx , I jy denote the moment of inertia of the sectional area of the joint region around the strong axis and the weak axis, respectively, E e I ex , E e I ey denote the combined stiffness of the PEC vertical member around the strong axis and the weak axis, respectively, E c denotes the elastic modulus of concrete, I cx , I cy denote the moment of inertia of the concrete part of the sectional area of the PEC member around the strong axis and the weak axis, respectively, I sx , I sy denote the moment of inertia of the steel skeleton part of the sectional area of the PEC member around the strong axis and the weak axis, respectively;

[0030] 3.4): the shear capacity checking calculation of the joint region, so that the shear capacity of the two principal axis directions of the PEC member is under the shear capacity envelope of the joint region, the calculation formula is as follows:

[0031] V uj ≥V​​u

[0032] In the above formula, V uj represents the node area section shear capacity, V u represents the component area shear capacity.

[0033] Further, in the step 5), the calculation of the diaphragm thickness is that the diaphragm between the two cross webs is calculated as a simply supported beam, and the diaphragm of the cantilever part outside the stiffened plate is calculated as a cantilever beam. The concrete compressive stress borne by the diaphragm of the cantilever part is transmitted to the web through the diaphragm, and then transmitted to the lower PEC component through the web. The lower PEC component has the same stress mode as the upper PEC component, but the stress direction is opposite. The diaphragm thickness obtained by calculating the diaphragm of the cantilever part is compared with the diaphragm thickness obtained in step 5), and the maximum value between the two is taken as the diaphragm thickness.

[0034] Further, in the assumption of internal force transmission in step 5), if the web of the upper PEC component is disconnected below the diaphragm, attention should be paid to the analysis of the web stress of the upper PEC component. The internal force of the web of the upper PEC component is transmitted to the web through the beam composed of the diaphragm and the stiffened plate, and then transmitted to the lower PEC component through the web.

[0035] The splicing node design method disclosed in the present application is based on equal strength design, and is designed and calculated under the principle of ensuring that the node area plate has a bearing capacity, stiffness, local stability and seismic resistance not lower than that of the component. The design method of the present application is suitable for the splicing connection of the PEC vertical component (including columns and walls) and provides a theoretical basis and quantitative calculation method for the design of such splicing node. The force transmission path is clear and definite, which is conducive to the implementation of the splicing node of the PEC vertical component. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 It is the flow chart of the PEC vertical component splicing node design method in the embodiment;

[0037] Figure 2 It is the schematic diagram of the PEC vertical component splicing node in the embodiment;

[0038] Figure 3 It is Figure 2 the internal structure schematic diagram after removing the concrete in the embodiment;

[0039] Figure 4 It is the cross-sectional view of the web of the upper PEC component in the PEC vertical component splicing node when the web is continuous;

[0040] Figure 5A sectional view of the web discontinuity of the upper PEC member in the PEC vertical member splicing joint.

[0041] Reference signs:

[0042] 1, upper PEC member; 2, lower PEC member; 3, cross diaphragm; 4, stiffener plate; 5, side plate; 6, longitudinal reinforcement; 7, link; 8, concrete. DETAILED DESCRIPTION

[0043] The technical solutions in the embodiments of the application will be clearly and completely described in combination with the drawings in the embodiments of the application.

[0044] The embodiment discloses a non-pouring PEC vertical member splicing joint, and simultaneously discloses a design method of the splicing joint. The PEC vertical member can be a PEC column or a PEC shear wall, and the embodiment takes the vertical splicing of the PEC column as an example for display. First, the structure of the PEC vertical member splicing joint of the application is introduced, as shown in Figure 2 and Figure 3 The PEC vertical member splicing joint comprises an upper PEC member 1, a lower PEC member 2 and two side plates 5. The upper PEC member 1 and the lower PEC member 2 are similar in structure, and the structure of the upper PEC member 1 is taken as an example for description.

[0045] The steel skeleton in the upper PEC member 1 is an H-shaped steel, and the web of the H-shaped steel is provided with longitudinal reinforcements 6 and links 7 on both sides, the links 7 are perpendicular to the longitudinal reinforcements 6, and the two are fixed by binding. A cross diaphragm 3 is arranged at the position close to the lower end of the upper PEC member 1, the cross diaphragm 3 is perpendicular to and fixedly connected with the web, and the cross diaphragm 3 is perpendicular to and fixedly connected with the flanges on both sides of the H-shaped steel. The web of the upper PEC member 1 is continuous below the cross diaphragm 3, and there are two setting structures, one is as shown in Figure 4 , the web of the upper PEC member 1 is continuous in the joint area, that is, the bottom surface of the web of the upper PEC member 1 is flush with the bottom surface of the flanges on both sides, and in this structure, one block of the cross diaphragm 3 needs to be arranged on each side of the web. The other structure is as shown in Figure 5 , the web of the upper PEC member 1 is disconnected in the joint area, that is, the web of the upper PEC member 1 only exists in the upper part of the cross diaphragm 3, and the lower part of the cross diaphragm 3 has no web, and in this structure, the cross diaphragm 3 is an integral plate. In addition, a stiffener plate 4 is arranged above the cross diaphragm 3, the stiffener plate 4 is perpendicular to the web and the cross diaphragm 3 respectively, the stiffener plate 4 is arranged at the longitudinal reinforcement 6, and the stiffener plate 4 is welded and fixed with the longitudinal reinforcement 6, the web and the cross diaphragm 3 respectively. The longitudinal reinforcement 6 is welded on the cross diaphragm 3, the ends of the link 7 are welded on the flanges, the web on the upper side of the cross diaphragm 3 is respectively poured with concrete 8, and the lower side of the cross diaphragm 3 is not poured.

[0046] The structure of the lower PEC member 2 is different from the upper PEC member 1 as follows: the web top surface of the lower PEC member 2 is flush with the two side flange top surfaces, the cross diaphragm 3 on the lower PEC member 2 is arranged at the top of the lower PEC member 2, and the two sides of the web below the cross diaphragm 3 on the lower PEC member 2 are both poured with concrete 8. The unmentioned part of the lower PEC member 2 can be referred to the above description of the structure of the upper PEC member 1.

[0047] When the upper PEC member 1 and the lower PEC member 2 are vertically spliced, the flanges of the upper PEC member 1 are correspondingly welded with the flanges of the lower PEC member 2, and if the web of the upper PEC member 1 is a continuous structure, the web bottom of the upper PEC member 1 is welded with the top surface of the cross diaphragm 3 of the lower PEC member 2. Two side plates 5 are arranged below the cross diaphragm 3 of the upper PEC member 1 at intervals, the side plates 5 are parallel to the web, each side plate 5 needs to be arranged at the position of the longitudinal reinforcement 6, the top of the side plate 5 is welded with the cross diaphragm 3 of the upper PEC member 1, and the bottom of the side plate 5 is welded with the top of the cross diaphragm 3 of the lower PEC member 2.

[0048] When designing the splicing joint of the above pouring-free PEC vertical member, as shown in Figure 1 , the following design method is adopted:

[0049] Step 1): First, the above PEC vertical member splicing joint is constructed.

[0050] Step 2): According to the constructed splicing joint, the distance between the cross diaphragm 3 of the upper PEC member 1 and the cross diaphragm 3 of the lower PEC member 2 is determined, thereby the height of the side plate 5 can be preliminarily determined; then according to the internal retreat size of the installation position of the side plate 5 (i.e. the distance between the outer side surface of the side plate 5 and the flange end surface), the thickness of the side plate 5 can be preliminarily determined, and then the joint area cross-sectional shape of the PEC vertical member splicing joint is drawn. If the upper PEC member 1 adopts a continuous web structure, the joint area cross-sectional shape is in the shape of Figure 4 Ⅲ; if the upper PEC member 1 adopts a discontinuous web structure, the joint area cross-sectional shape is in the shape of Figure 5 Ⅱ.

[0051] Step 3): According to the stiffness envelope principle, it is reversely calculated or checked whether the thickness of the side plate 5 determined in step 2) meets the design requirements. The verification principle of this step is as follows: the stiffness, strength and stability in the two main directions of the joint area are not lower than those in the two main directions of the member area, thereby the thickness of the side plate 5 is reviewed. If the above principle is met, step 4) is continued to be executed, if the above condition is not met, the thickness of the side plate 5 determined in step 2) is adjusted according to the checking result until the above principle is met.

[0052] Specifically, the thickness of the side plate 5 needs to be calculated as follows:

[0053] 1) The axial compression bearing capacity of the joint area is greater than that of the PEC member area, and the calculation formula is as follows:

[0054] N uj ≥N u

[0055] In the above formula, N uj represents the axial compression bearing capacity of the joint area section, and N u represents the axial compression bearing capacity of the member area.

[0056] 2) The compression-bending strength bearing capacity calculation makes the M-N curves of the two principal axes of the PEC member within the envelope range of the M-N curves of the joint area, and the calculation formula is as follows:

[0057] ρ u ≥ρ uj

[0058]

[0059]

[0060] In the above formula, ρ uj represents the compression-bending stress ratio of the joint area section, and ρ u represents the compression-bending stress ratio of the member area; N represents the axial force design value on the section; M x , M y represent the bending moment design value around the x-axis and the bending moment design value around the y-axis; N u represents the compression bearing capacity design value of the section; N mx , N my represent the characteristic axial force for the x-axis and the y-axis; M ux , M uy represent the bending bearing capacity design value around the x-axis and around the y-axis; A n represents the net sectional area of the joint area steel; γ x , γ x represent the sectional plastic development coefficient for the principal axes x and y; f represents the steel tensile and compressive strength design value; W nx , W ny respectively represent the net sectional modulus for the x-axis and the y-axis.

[0061] 3) The joint area rigid envelope calculation formula is as follows:

[0062] E s I jx ≥E e I ex

[0063] E s I jy ≥Ee I ey

[0064] E e I ex =E s I sx +E c I cx

[0065] E e I ey =E s I sy +E c I cy

[0066] In the above formula, E s represents the elastic modulus of steel material, I jx , I jy respectively represent the moment of inertia of the section of the node zone around the strong axis and the weak axis, E e I ex , E e I ey respectively represent the combined stiffness of the PEC vertical member around the strong axis and the weak axis, E c represents the elastic modulus of concrete, I cx , I cy respectively represent the moment of inertia of the concrete part of the section of the PEC member around the strong axis and the weak axis, I sx , I sy respectively represent the moment of inertia of the steel skeleton part of the section of the PEC member around the strong axis and the weak axis.

[0067] 4) Node zone shear capacity checking, so that the shear capacity of the two principal axes of the PEC member is under the shear capacity envelope of the node zone, and the calculation formula is as follows:

[0068] V uj ≥V u

[0069] In the above formula, V uj represents the shear capacity of the section of the node zone, and V u represents the shear capacity of the member zone.

[0070] Step 4): Preliminarily determine the height and thickness of the stiffened plate 4 and the thickness of the cross partition plate 3.

[0071] Step 5) : Based on the size determined in step 4), the thickness of stiffened plate 4 and cross partition plate 3 is checked, the strength of stiffened plate 4 and cross partition plate 3 under the action of axial force and bending moment is checked to ensure that the stress does not exceed the steel strength design value. If the verification result meets the design requirements, step 6) is continued, if it does not meet the design requirements, the size of stiffened plate 4 and cross partition plate 3 is adjusted according to the checking result until the requirements are met.

[0072] In this step, when checking the stress of the node area stiffened plate 4 and cross partition plate 3, the internal force transmission path of the PEC vertical component splicing node of the present application needs to be determined first. The present application assumes that the internal force transmission path is as follows: the compressive stress of the concrete of the upper PEC component 1 under the action of axial force and bending moment (if the web of the upper PEC component 1 adopts a discontinuous structure, the stress of the web is also included, the web stress is as follows: the web internal force of the upper PEC component 1 is transmitted to the side plate 5 through the beam composed of the cross partition plate 3 and the stiffened plate 4, and then transmitted to the lower PEC component 2 by the side plate 5), the inverted T beam structure composed of the cross partition plate 3 and the stiffened plate 4 is transmitted to the two side plates 5, and then the force is transmitted to the lower PEC component 2 through the side plate 5, the lower PEC component 2 has the same stress mode as the upper PEC component 1, but the stress direction is opposite.

[0073] Further, according to the above internal force transmission analysis, the thickness of the cross partition plate 3 is checked by combining the cross partition plate 3 between the two-span side plates 5 and the stiffened plate 4 as a simply supported beam, but the cross partition plate 3 of the overhanging part outside the stiffened plate 4 should be checked for its strength as a cantilever beam. The concrete compressive stress borne by the cross partition plate 3 of the overhanging part is transmitted to the side plate 5 through the cross partition plate 3, and then transmitted to the lower PEC component 2 through the side plate 5, the lower PEC component 2 has the same stress mode as the upper PEC component 1, but the stress direction is opposite. The thickness of the cross partition plate 3 obtained after checking the cross partition plate 3 of the overhanging part is between the thickness of the cross partition plate 3 obtained by checking as a simply supported beam and the thickness of the cross partition plate 3 obtained by checking as a cantilever beam, and the maximum thickness is taken as the thickness of the cross partition plate 3.

[0074] Step 6) : After determining the size of the side plate 5, the cross partition plate 3 and the stiffened plate 4 in step 3) and step 5), the size needs to be reviewed according to the specification construction requirements, that is, the value of the side plate 5, the cross partition plate 3 and the stiffened plate 4 is determined according to the requirements of the relevant specifications for pure steel components according to the seismic grade, to ensure the local stability of the component, and the value is taken as the final determined size.

[0075] Step 7) : After the above size determination is completed, the correctness of the force transmission of the splicing node assumed by the present application needs to be verified, that is, a PEC vertical component splicing node model is constructed and loaded by using a finite element analysis software, based on the size of the side plate 5, the cross partition plate 3 and the stiffened plate 4 determined in step 6), the stress distribution of the splicing node under the action of axial force, bending moment and shear force is calculated and analyzed.

[0076] Step 8): after the correctness of the assumed force transmission has been verified by step 7), the influence of the splicing joint of the application on the seismic performance of the monomer building structure system is further analyzed, that is, according to the position of the PEC vertical component splicing joint in the floor (generally at 1.2m-1.3m high of the floor), the structure design software is used to respectively establish the structure system model of the PEC vertical component splicing joint of the application and the common structure model in the prior art, the size of the side plate 5, the cross partition plate 3 and the stiffener plate 4 determined in step 6) are respectively introduced into the above two models, then the indexes of the two models are calculated and compared, and the corresponding index calculation results of the two models are consistent.

[0077] In summary, the application specifies the calculation process and formula of the non-pouring splicing joint, and completes the calculation of the splicing connection of the PEC vertical component. Its beneficial effects are as follows: 1) It fills the gap of the non-pouring joint calculation method. 2) It provides a feasible method for the calculation of the PEC joint. 3) It provides theoretical and formula basis for the compilation of the non-pouring joint calculation software.

[0078] Although the embodiments of the application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the application, and the scope of the application is defined by the appended claims and their equivalents.

Claims

1. A design method for splicing nodes of PEC vertical components, characterized in that, The method comprises the following steps: Step 1): constructing a PEC vertical component splicing joint; The PEC vertical component splicing joint comprises an upper PEC component, a lower PEC component and side plates, the upper PEC component and the lower PEC component each comprise flanges on two sides, a web connecting the flanges, longitudinal reinforcement on two sides of the web, connecting rods perpendicular to the longitudinal reinforcement on two sides of the web, a cross web plate connected perpendicularly to the web and the flanges, a stiffener plate connected perpendicularly to the cross web plate and the web, and concrete filled in the web on two sides with the cross web plate as a separation line; the bottom surface of the cross web plate in the upper PEC component is higher than the bottom surface of the flange of the upper PEC component, the top surface of the cross web plate in the lower PEC component is flush with the top surface of the flange of the lower PEC component, the flange of the upper PEC component is welded to the flange of the lower PEC component, two side plates are arranged at intervals between the cross web plate of the upper PEC component and the cross web plate of the lower PEC component, the side plates are parallel to the web, the positions of the side plates correspond to the positions of the longitudinal reinforcement, the stiffener plate is fixed to the longitudinal reinforcement, the top end of the side plate is welded to the bottom of the cross web plate of the upper PEC component, and the bottom end of the side plate is welded to the top of the cross web plate of the lower PEC component; Step 2): preliminarily determining the thickness of the side plate according to the distance between the cross web plate of the upper PEC component and the cross web plate of the lower PEC component and according to the internal retreat size of the installation position of the side plate, and drawing the cross-sectional shape of the joint area of the PEC vertical component splicing joint; Step 3): checking whether the thickness of the side plate determined in step 2) satisfies the following conditions: the stiffness, strength and stability in the two main axis directions of the joint area are not lower than the stiffness, strength and stability in the two main axis directions of the component area; if the above conditions are satisfied, step 4) is continued to be executed, and if the above conditions are not satisfied, the thickness of the side plate is adjusted according to the checking result until the above conditions are satisfied; Step 4): preliminarily determining the height and thickness of the stiffener plate and the thickness of the cross web plate; Step 5): assuming that the internal force transmission of the upper and lower PEC components of the PEC vertical component splicing joint is as follows: the compressive stress of the concrete of the upper PEC component under the action of axial force and bending moment is transmitted to the two side plates through the inverted T-beam structure composed of the cross web plate and the stiffener plate, and then the force is transmitted to the lower PEC component through the side plates, the lower PEC component has the same stress mode as the upper PEC component but the stress direction is opposite; Based on the analysis result of the internal force transmission under the above assumption, the strength of the stiffener plate and the cross web plate determined in step 4) under the action of axial force and bending moment is checked to ensure that the stress does not exceed the design value of the steel strength, if the verification result meets the design requirements, step 6) is continued to be executed, and if the verification result does not meet the design requirements, the dimensions of the stiffener plate and the cross web plate are adjusted according to the checking result until the stress requirement is met; Step 6): based on the dimensions of the side plate, the cross web plate and the stiffener plate determined in steps 3) and 5), the dimensions of the side plate, the cross web plate and the stiffener plate are valued according to the requirements of the pure steel component in the specification according to the seismic grade, and the valued result is taken as the finally determined dimensions; Step 7): The finite element analysis software is used to build the PEC vertical component splicing joint model, the stress distribution of the splicing joint under the axial force, bending moment and shear force is calculated and analyzed based on the size of the side plate, cross partition plate and stiffener plate determined in step 6), and the correctness of the internal force transmission assumption of the splicing joint in step 5) is verified; Step 8): According to the position of the PEC vertical component splicing joint in the floor, the structure system model of the PEC vertical component splicing joint and the ordinary structure model in the prior art are respectively established by using the structure design software, the size of the side plate, cross partition plate and stiffener plate determined in step 6) is respectively introduced into the above two models, then the indexes of the two models are calculated and compared, and the corresponding index calculation results of the two models are kept consistent.

2. The design method of a PEC vertical member spliced node according to claim 1, characterized in that: In the step 2), when the web bottom surface of the upper PEC component is flush with the flange bottom surface of the upper PEC component, the node area cross section shape is III type; when the web of the upper PEC component is arranged only on the upper part of the cross partition plate, the node area cross section shape is II type.

3. The method of designing a PEC vertical member splice joint of claim 1, wherein: In the step 3), the following calculations are required for checking the thickness of the side plate: 3.1): axial compression bearing capacity checking, to ensure that the axial compression bearing capacity of the node area is greater than that of the PEC component area, the calculation formula is as follows: N uj ≥N u In the above formula, N uj represents the axial load-carrying capacity of the node zone cross-section, N u represents the axial load-carrying capacity of the member zone; 3.2): compression bending strength bearing capacity checking, to make the M-N curves of the two main axes of the PEC component within the M-N curve envelope range of the node area, the calculation formula is as follows: p u ≥ p uj In the above formula, ρ uj represents the sectional compressive-bending stress ratio of the node region, ρ u represents the sectional compressive-bending stress ratio of the member region; N represents the design value of the axial force on the section; M x , M y represents the design value of the bending moment around the x axis and the design value of the bending moment around the y axis; N u represents the design value of the compressive capacity of the section; N mx , N my represents the characteristic axial force for the x axis and the y axis; M ux , M uy represents the design value of the flexural capacity around the x axis and around the y axis; A n represents the net sectional area of the steel member in the node region; γ x , γ x represents the sectional plastic development coefficient for the principal axes x and y; f represents the design value of the tensile and compressive strength of the steel; W nx , W ny represents the net sectional modulus for the x axis and the y axis, respectively; 3.3): node area rigid envelope checking, the calculation formula is as follows: E s I jx ≥E e I ex E s I jy ≥E e I ey E e I ex = E s I sx + E c I cx E e I ey = E s I sy + E c I cy In the above formula, E s represents the steel elastic modulus, I jx , I jy respectively represent the inertia moment of the node area section around the strong axis and the weak axis, E e I ex , E e I ey respectively represent the combined stiffness of the PEC vertical member around the strong axis and the weak axis, E c represents the concrete elastic modulus, I cx , I cy respectively represent the inertia moment of the concrete part of the PEC member section around the strong axis and the weak axis, I sx , I sy respectively represent the inertia moment of the steel skeleton part of the PEC member section around the strong axis and the weak axis; 3.4): node area shear bearing capacity checking, to make the shear bearing capacity of the two main axes of the PEC component below the node area shear bearing capacity envelope, the calculation formula is as follows: V uj ≥V u In the above formula, V uj represents the nodal zone shear capacity, V u represents the member zone shear capacity.

4. The method of designing a PEC vertical member splice joint of claim 1, wherein: In the step 5), the cross partition plate and the stiffener plate located between the two-span side plates are combined as a simply supported beam for checking the thickness of the cross partition plate, and the cross partition plate of the cantilever part outside the stiffener plate is checked as a cantilever beam, the concrete compressive stress borne by the cross partition plate of the cantilever part is transmitted to the side plate through the cross partition plate, and then transmitted to the lower PEC component through the side plate, the lower PEC component has the same stress mode as the upper PEC component but the stress direction is opposite; the maximum value between the cross partition plate thickness obtained after checking the cross partition plate of the cantilever part and the cross partition plate thickness obtained in step 5) is taken as the thickness of the cross partition plate.

5. The method of designing a PEC vertical member splice joint of claim 2, wherein: In the assumption of internal force transmission in the step 5), if the web of the upper PEC component is disconnected below the cross partition plate, the stress of the web of the upper PEC component needs to be analyzed as follows: the internal force of the web of the upper PEC component is transmitted to the side plate through the beam composed of the cross partition plate and the stiffener plate, and then transmitted to the lower PEC component by the side plate.

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