Rapid Design Method for Foundation Pit Support Structure of Raft Foundation

Abstract

The present invention discloses a rapid design method for the supporting structure of a pile cap foundation pit, which comprises the following steps: establishing the pile cap pile foundation object in the bridge structure by using the BIM system; selecting the pile cap pile foundation object, and establishing the supporting elevation layout object group, the supporting plan layout object group, the supporting structure elevation detail object and the supporting structure design management object, so as to rapidly construct the BIM model for the design of the supporting structure of the pile cap foundation pit, conveniently express the design schemes of the supporting piles and the internal support structure of the supporting structure, and conveniently complete the strength, stiffness and stability calculations of the two-dimensional / three-dimensional structure of the supporting structure, thereby obtaining the design details and the engineering quantity list of the supporting structure. The present invention realizes the simplification, standardization and high efficiency of the design of the bridge pile cap supporting structure, can be applicable to the types of supporting piles such as steel sheet piles, section steel piles, locked steel pipe piles, concrete piles, etc., and can also be adapted to the design of similar foundation pits of other buildings.

Description

Technical Field

[0001] The present invention relates to a construction method for bridge engineering, and more particularly to a rapid design method for the supporting structure of a pile cap foundation pit. Background Art

[0002] In bridge construction, a large number of pile cap foundation pit constructions are involved, which account for a large economic volume in bridge construction. Correspondingly, the digital technology for the design of the foundation pit supporting structure is an important part of the overall technology system of bridge construction digitization. Currently, although some software tools can assist in the design of the pile cap foundation pit supporting structure, from the perspective of key design processes such as scheme comparison and selection, structural calculation, drawing generation, and engineering quantity calculation, the current software tools are still difficult to collaboratively complete the key design processes of the pile cap foundation pit supporting structure design. The information flow of each design link is poor, which restricts the full exploration of the design efficiency of the supporting structure.

[0003] BIM (Building Information Modeling) technology is a technology for the construction and application of models that uses graphics as a carrier and can load or associate many relevant engineering information at the same time. This technology is a key technology in the digital technology field of bridge intelligent construction technology.

[0004] CN119337486A discloses a rapid design method for a beam-column type support based on functional graphic objects. This method first establishes basic graphic objects in an interactive drawing system; then, by establishing a longitudinal layout object group and a transverse layout object group of the beam-column type support, modifying the longitudinal layout scheme and the transverse layout scheme of the steel pipe columns, a finite element calculation model of the members is established to calculate the maximum number of required main load-bearing beams; by dividing the equal load area of the main beam reference section, a plan layout diagram including large cross beams, small cross beams, and main load-bearing beams, a plan layout diagram of the steel pipe column foot plane, and a plan layout diagram of the concrete strip foundation plane are established; by establishing a finite element calculation model of the members for the designed beam-column type support, the mechanical calculation results of the beam-column type support are calculated, and finally an engineering quantity table of the beam-column type support design scheme is formed. This rapid design method for the beam-column type support can quickly realize the scheme design and mechanical calculation of the beam-column type support by creating and operating two-dimensional functional graphic objects, and quickly obtain construction details and engineering quantities.

[0005] However, since the pile cap foundation pit supporting structure and the beam-column type support belong to different structural systems, have different design characteristics, and the expressions of the design characteristics are also completely different, the rapid design method of the beam-column type support cannot be used or referred to for the rapid design and calculation of the pile cap foundation pit supporting structure. Therefore, in the existing bridge construction digital technology, there is still a lack of an integrated solution that can support the design, calculation, quantity calculation, and drawing of the bridge pile cap foundation pit supporting structure. Figure 1 of the body. Summary of the Invention

[0006] The object of the present invention is to provide a rapid design method for the supporting structure of the pile cap foundation pit, so as to overcome the deficiencies of the existing technology and realize the integration of the design, calculation, quantity calculation and drawing of the supporting structure of the bridge pile cap foundation pit.

[0007] The object of the present invention is achieved as follows:

[0008] A rapid design method for the supporting structure of the pile cap foundation pit includes the following steps:

[0009] S1. According to the design data of the bridge structure, use the BIM system to establish the pile cap pile foundation object in the bridge structure.

[0010] S2. Given the pile cap plane and the static spacing from the inner edge of the retaining pile plane to the edge of the pile cap, respectively establish the retaining elevation layout object group, the retaining plane layout object group, the retaining elevation layout detail object and the retaining structure design management object through the pile cap pile foundation object.

[0011] S3. By modifying the attribute information of the retaining structure design management object or through the editing operation of the objects in the retaining elevation layout object group, obtain the retaining elevation layout object group that meets the on-site hydrogeological requirements; according to the number of inner support elevations, obtain an equal number of retaining plane layout object groups by copying or deleting.

[0012] S4. By setting the static spacing from the inner edge of the retaining pile plane to the edge of the pile cap plane, obtain the retaining plane layout object group that meets the requirements of this static spacing.

[0013] S5. Set the cross-section specifications and layout attribute information of the struts and inclined struts on the inner support plane object in each retaining plane layout object group to obtain the required inner support plane object.

[0014] S6. According to the retaining elevation layout object group obtained in step S3 and the inner support plane object obtained in step S5, perform structural calculations on the inner support structure in the retaining structure, and then respectively perform mechanical calculations on the overall stability, embedded stability and anti-heave of the foundation pit retaining.

[0015] S7. Repeat steps S4 - S6 until the mechanical calculation results that meet the technical specification requirements are obtained and a calculation book is generated.

[0016] S8. According to the retaining elevation layout object group and each retaining plane layout object group, set the backfilling parameters of concrete or soil, and establish the retaining elevation layout detail object corresponding to each working condition in the whole process from the installation to the demolition of the inner support structure one by one.

[0017] S9. Set the bracket support layout information, corner brace layout information, ring beam stiffener layout information, and adjustment joint layout information for the strut and diagonal brace in each support plane layout object group respectively, and establish the design details of the ring beam, strut, and diagonal brace in each internal support structure; and establish the engineering quantity table of the internal support structure and the retaining piles according to the support elevation layout object group and each support plane layout object group.

[0018] Furthermore, the present invention further includes the following steps:

[0019] S10. Supplement local details to the design details of the ring beam, strut, and diagonal brace of each internal support structure to complete the design details of the foundation pit support structure of the bearing platform.

[0020] Furthermore, in step S5, when the required internal support plane object cannot be obtained by setting the attribute information and modifying the attribute information, first decompose the internal support plane object into independent member objects including the ring beam, strut, and diagonal brace, then establish the required member objects including the ring beam, strut, and diagonal brace through the drawing and editing methods of the member objects, and finally, combine the established member objects and force them to be converted into the required internal support plane object.

[0021] The present invention is implemented by creating and operating functional graphic objects. The functional graphic objects have the following basic characteristics:

[0022] 1. The functional graphic object is a two-dimensional geometric graphic object in the graphic system, similar to the block object in AutoCAD, and geometric operations such as selection, movement, copying, enlargement, and reduction can be performed. However, different from it, the functional graphic object needs to customize special engineering attribute information and professional functions for the functional object. The operation interface of the functional graphic object can be activated by the mouse, and the relevant attribute information or parameter information of the functional graphic object and some operation buttons for implementing professional functions are displayed on the operation interface. By clicking the relevant button operations, the professional functions of the functional graphic object can be realized, and the corresponding operations are the professional operations of the functional graphic object. Therefore, the functional graphic object is also an information model in the graphic system.

[0023] 2. The functional graphic object can be obtained through parametric and forced conversion methods. For simple functional graphic objects, they can be realized through parametric methods, that is, the required functional graphic objects can be created by entering several parameters. For complex functional graphic objects, the forced conversion method can be adopted.

[0024] 3. The forced conversion method is a basic method for converting geometric graphic objects into functional graphic objects with engineering attributes and professional functions. The basic steps for implementing the forced conversion method are as follows: First, draw a geometric graphic object using the interactive geometric graphic drawing and editing method; then, through mouse operations, load or associate relevant engineering data in the graphic data of the geometric graphic object and provide corresponding professional functions.

[0025] 4. The functional graphic object itself is a type of graphic data, which contains data reflecting its geometric shape and data reflecting its engineering characteristics, and can be recognized and extracted for corresponding engineering calculations.

[0026] The present invention belongs to a method for editing the attributes of functional graphic objects. For the established functional graphic objects, the attribute information of the functional graphic objects can be set through its operation interface to obtain the required functional graphic objects and display states.

[0027] The present invention quickly constructs the key BIM model for the design of the pile cap foundation pit support structure by establishing functional graphic objects such as the support elevation layout object group, the support plan layout object group, and the support structure elevation detail object in the graphic system, conveniently expresses the design schemes of the support piles and the internal support structure of the support structure, quickly completes the strength, stiffness, and stability calculations of the two-dimensional / three-dimensional structure of the support structure, as well as the relevant stability calculations required by the specifications, quickly obtains the design details and engineering quantity list of the pile cap foundation pit support structure, realizes the simplification, standardization, and high efficiency of the design of the bridge pile cap support structure, is beneficial to the refined management and control of bridge engineering construction projects, and is beneficial to the potential tapping and efficiency increase of construction enterprises.

[0028] The present invention adopts BIM technology to conveniently express the design schemes of the support piles and the internal support structure of the support structure by establishing functional graphic objects such as the support elevation layout object group, the support plan layout object group, and the support structure elevation detail object in the graphic system during the design process of the bridge pile cap foundation pit support structure, complete the strength, stiffness, and stability calculations of the two-dimensional / three-dimensional structure of the support structure, and the relevant stability calculations required by the specifications, quickly obtain the design details and engineering quantity list of the support structure, realize the simplification, standardization, and high efficiency of the design of the bridge pile cap support structure, and is beneficial to the refined management and control of bridge engineering construction projects and the potential tapping and efficiency increase of construction enterprises.

[0029] The present invention has good adaptability and can adapt to support pile types such as steel sheet piles, steel section piles, locked steel pipe piles, and concrete piles, and can also adapt to the design of support structures for similar foundation pits of other buildings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1They are the three-view drawings of the pile cap foundation object; among them, (a) is the front view, (b) is the top view, and (c) is the left view.

[0031] Figure 2 It is a schematic diagram of the support elevation layout object group.

[0032] Figure 3 It is a schematic diagram of the support plan layout object group.

[0033] Figure 4 It is a schematic diagram of the support elevation layout detail object.

[0034] Figure 5 It is a schematic diagram of the support structure design management object.

[0035] Figure 6 It is a schematic diagram of the foundation pit soil layer object.

[0036] Figure 7 It is a schematic diagram of the uniformly distributed load object covering the whole area.

[0037] Figure 8 It is a schematic diagram of the strip uniformly distributed load object.

[0038] Figure 9 It is a schematic diagram of the rectangular uniformly distributed load object.

[0039] Figure 10 It is a schematic diagram of the water level line marking object.

[0040] Figure 11 It is a schematic diagram of the internal support plane object.

[0041] Figure 12 It is the design detail drawing of the internal support plane object with the internal support plane, bracket plane and support pile plane.

[0042] Figure 13 It is the design detail drawing of the internal support plane object with the ribbed plate plane and stiffened ribbed plate plane.

[0043] Figure 14 It is the structural schematic diagram of various plane members of the internal support structure.

[0044] Figure 15 It is the structural schematic diagram of various joints; among them, (a) is the structural schematic diagram of the first type of cross brace joint; (b) is the structural schematic diagram of the second type of cross brace joint; (c) is the structural schematic diagram of the inclined brace joint; (d) is the structural schematic diagram of the cross brace joint assembled by multiple joints; (e) is the structural schematic diagram of the inclined brace joint assembled by multiple joints.

[0045] Figure 16 It is the structural schematic diagram of the internal support bracket.

[0046] Figure 17 It is a structural schematic diagram of a member; among them, (a) is the elevation view of the member; (b) is the plan view of the member; (c) is the cross-sectional view of the member.

[0047] In the figure: G is the elevation object of the retaining pile; S is the elevation object of the internal support; C is the elevation object of the bearing platform; D is the elevation object of the bottom-sealing concrete; Q1 is the uniformly distributed load over the entire area; Q2 is the uniformly distributed rectangular load; Q3 is the uniformly distributed strip load; W is the water level line marking object; H is the elevation object of the foundation pit soil layer; Gp is the group of plan objects of the retaining pile; T1 is the plan object of the bearing platform; WL is the plan object of the internal support; L is the boundary line between the active zone and the passive zone; d is the elevation object of the foundation pit soil layer; Dis is the distance of the boundary line; QL is the ring beam; DC is the cross brace; XC is the inclined brace; NT is the corbel plane; JT is the joint plane; JB is the stiffening rib plate. Specific implementation manner

[0048] Two explanations:

[0049] 1. In the process of using functional graphic objects to process road and bridge construction technologies, the representations of various structural components in the graphic interface are all referred to as "XX objects"; for example: "bearing platform pile foundation object", "foundation pit soil layer object", "internal support plan object", "elevation layout detail object of the retaining structure", etc.

[0050] 2. The "preset interface" mentioned in the present invention refers to the preset operation interface in the graphic system or the operation interface of the functional graphic object.

[0051] The present invention also involves the following multiple professional terms, including the bearing platform pile foundation object, the elevation object of the foundation pit soil layer, the uniformly distributed load object over the entire area, the uniformly distributed strip load object, the uniformly distributed rectangular load object, the water level line marking object, the elevation object of the retaining pile, the plan object of the retaining pile, the elevation object of the internal support, the plan object of the internal support, the retaining structure design management object, the bottom-sealing concrete object, the joint object, the internal support corbel object, the member object, and the elevation detail object of the bearing platform foundation pit, etc. The following is a separate description of these professional terms:

[0052] I. The bearing platform pile foundation object is a two-dimensional functional graphic object with the following basic characteristics:

[0053] 1. The bearing platform pile foundation object is a functional graphic object composed of a plan view, an elevation view and a left view, and has attribute information such as the name of the bearing platform pile foundation, the height of the bearing platform, and the view display state.

[0054] 2. One method of establishing the bearing platform pile foundation model is to construct the bearing platform pile foundation object by using the parametric method; another method is to first draw the geometric graphics of the bearing platform pile foundation plane, merge them into a whole graphic and then convert it into the bearing platform pile foundation object, and then modify its attribute information on the preset interface to obtain the required bearing platform pile foundation object.

[0055] 3. Select the pile foundation object of the bearing platform. By specifying the static distance between the given bearing platform plane and the inner edge of the retaining pile plane to the edge of the bearing platform, a group of retaining plane layout objects composed of the inner support plane object, the bearing platform pile foundation plane object, and a series of retaining pile plane objects can be established, as well as a group of retaining elevation layout objects composed of the retaining pile elevation object, the foundation pit soil layer elevation object, the inner support elevation object, the bearing platform elevation object, the water level line marking object, the uniformly distributed load object, the rectangular uniformly distributed load object, the strip uniformly distributed load object, and the bottom sealed concrete elevation object; the detailed drawing object of the retaining elevation layout and the retaining structure design management object can also be established therefrom.

[0056] II. The foundation pit soil layer elevation object is a two-dimensional functional graphic object with the following basic characteristics:

[0057] 1. Figure 7 In [reference], d refers to the foundation pit soil layer elevation object. The foundation pit soil layer elevation object is also a symbol object used to express the soil layer distribution and soil layer parameter information in the active and passive zones of the foundation pit soil layer. The names of each soil layer, the soil layer dividing line, the unit weight, cohesion, internal friction angle of each soil layer, and whether the water and soil are calculated separately and other soil layer parameter information are displayed on its graph, and it has attribute information such as ground elevation, foundation pit excavation depth, font display height, soil layer parameters in the active and passive zones, and soil layer slope parameters.

[0058] 2. The soil layer parameter information in the active and passive zones includes the name, thickness, unit weight, cohesion, internal friction angle, whether the water and soil are calculated separately, buoyant unit weight, underwater internal friction angle, underwater cohesion, friction resistance with the anchor body, horizontal reaction coefficient, proportional coefficient, etc. of each soil layer.

[0059] 3. When the soil layer parameter information in the passive zone is empty, it means that the soil layer parameter information in the passive zone is the same as that in the corresponding elevation position in the active zone.

[0060] 4. The soil layer slope parameter refers to the slope parameter of the active zone ground, including the horizontal distance from the slope foot point to the edge of the foundation pit, the slope height, and the slope rate of the slope.

[0061] 5. In the preset interface, the attribute information of the foundation pit soil layer can be modified to obtain the required foundation pit soil layer object. The structure of the foundation pit soil layer object is as Figure 6 shown.

[0062] III. The uniformly distributed load object is a two-dimensional functional graphic object with the following basic characteristics:

[0063] 1. The uniformly distributed load object covering the whole area is arranged on the ground of the active area of the foundation pit soil layer object. Its lower left end point is located at the boundary line of the foundation pit and has attribute information such as uniformly distributed load value, load display height, and font display height, representing that the foundation pit soil layer object bears a uniformly distributed load covering the whole area in the active area. On the preset interface, the size of the uniformly distributed load covering the whole area can be changed by modifying attribute information such as the load value. As Figure 7 shown, the uniformly distributed load object covering the whole area Q1 is arranged on the ground of the active area of the foundation pit soil layer object d.

[0064] IV. The strip uniformly distributed load object is a two-dimensional functional graphic object with the following basic characteristics:

[0065] As Figure 8 shown, the strip uniformly distributed load object Q2 is arranged in the active area of the foundation pit soil layer object d and can be located at a certain position above or below the ground line of the active area. It has attribute information such as uniformly distributed load value, width of the strip uniformly distributed load, load display height, and font display height, representing that the foundation pit soil layer object bears a strip uniformly distributed load in the active area. The attribute information of the strip uniformly distributed load object Q2 can be modified on the preset interface. Figure 9 In, the distance between the strip uniformly distributed load object Q2 and the foundation pit boundary line of the foundation pit soil layer object d is Dis.

[0066] V. The rectangular uniformly distributed load object is a two-dimensional functional graphic object with the following basic characteristics:

[0067] As Figure 9 shown, the rectangular uniformly distributed load object Q3 is arranged in the active area of the foundation pit soil layer object d and can be located at a certain position above or below the ground line of the active area. It has attribute information such as uniformly distributed load value, width and length of the rectangular uniformly distributed load, load display height, and font display height, representing that the foundation pit soil layer object bears a rectangular uniformly distributed load in the active area. The attribute information of the rectangular uniformly distributed load object Q3 can be modified on the preset interface. Figure 10 In, the distance between the rectangular uniformly distributed load object Q3 and the foundation pit boundary line of the foundation pit soil layer object d is Dis.

[0068] VI. The water level line marking object is a two-dimensional functional graphic object with the following basic characteristics:

[0069] As Figure 10 shown, the water level line marking object is a two-dimensional symbol object used to represent the water level elevation information of the active area and passive area of the foundation pit. When there is no water in the soil layer, the water level marking object needs to be deleted.

[0070] VII. The retaining pile surface object is a two-dimensional functional graphic object with the following basic characteristics:

[0071] 1. The retaining pile elevation object is a functional graphic object in the shape of a rectangle with a certain filled shape or color, and it is a characteristic symbol used to represent the retaining pile structure in the foundation pit retaining structure of the pile cap. It has attribute information such as pile width, pile length, pile type, applicable construction technical specification type, pile material, pile specification, unit length weight, moment of inertia, and sectional moment.

[0072] 2. The pile types of the retaining piles include steel sheet piles, profiled steel, locked steel pipe piles, and reinforced concrete piles, etc.

[0073] 3. The pile specification is related to the pile type: for steel sheet piles, the pile specification is the model of the steel sheet pile, such as type IV and type VI steel sheet piles; for profiled steel retaining piles, the pile specification is the specification of the profiled steel, such as I45a profiled steel; for locked steel pipe piles, the pile specification is the steel pipe diameter and wall thickness, etc.

[0074] 4. The attribute information of the retaining pile elevation object can be modified on the preset interface to obtain the required retaining pile elevation object.

[0075] VIII. The retaining pile plan object is a two-dimensional functional graphic object with the following basic characteristics:

[0076] 1. The retaining pile plan object is a functional graphic object used to express the cross-section of the retaining pile, and its specific geometric shape is related to the pile type and pile specification of the retaining pile.

[0077] 2. The retaining pile plan object is established based on the retaining pile elevation object. According to the internal support plan object and the retaining pile elevation object, several retaining pile plan objects constrained by the boundary of the internal support plan object can be established, and these several retaining pile plan objects form a series, becoming a series of retaining pile plan objects.

[0078] 3. Based on the existing retaining pile plan object, the required retaining pile plan object can be established and obtained through operation methods such as deletion, copying, and moving.

[0079] IX. The internal support elevation object is a functional graphic object with the following basic characteristics:

[0080] 1. The internal support elevation object is a characteristic symbol object expressed by a rectangle, which is used to represent the elevation layout position of the internal support structure in the retaining structure. It has attribute information such as the height of the rectangular display, the width of the rectangular display, the color of the rectangular display, the name of the associated internal support plan object, and the corresponding elastic stiffness.

[0081] 2. The elastic stiffness represents the elastic stiffness of the internal support structure for supporting the retaining pile, and the corresponding elastic stiffness can be calculated through the corresponding internal support plan object.

[0082] 3. There are multiple independent internal support facade objects in the object group arranged on the support facade. Multiple internal support facade objects can be created through operations such as moving, deleting, and copying. One internal support facade object represents one internal support structure. The topmost internal support facade object corresponds to the first internal support structure, and the subsequent ones correspond to the second internal support structure, the third internal support structure, and so on. Each internal support facade object is associated with the corresponding internal support plane object through the name of the internal support plane object.

[0083] 4. The attribute information of the internal support facade object can be modified on the preset interface to obtain the required internal support facade object.

[0084] X. The internal support plane object is a functional graphic object with the following basic characteristics:

[0085] 1. The internal support plane object is a functional graphic object used to represent the internal support structure in the foundation pit support structure of the bearing platform; there are as many internal support plane objects as there are internal support facade objects.

[0086] 2. As Figure 11 shown, the internal support plane object is a planar member structure composed of ring beams QL, cross braces DC, and inclined braces XC, etc. The internal support plane object can be created through parametric methods or through forced conversion methods.

[0087] 3. For the internal support plane object created through parametric methods, its attribute information includes the name of the internal support plane object, the external contour dimensions of the internal support structure in the plane, the specifications of each planar member in the internal support structure, the uniform load transmitted by the supporting piles and the design information of the ring beam rib plates, the layout information of the bracket corbels at the internal support positions, and the parametric design information for the design of the internal support plane object, etc.

[0088] 4. To create an internal support plane object through forced conversion, first decompose the internal support plane object created through parametric methods into corresponding planar member objects such as Figure 14 shown ring beams QL, inclined braces XC, cross braces DC, etc. Then, through geometric operations or professional operations on the inclined braces and cross braces, obtain the planar member objects representing the internal support plane object. After combining these planar member objects, through forced conversion, obtain the corresponding internal support plane object. The internal support plane object obtained through forced conversion has attribute information such as the name and the uniform load transmitted by the supporting piles.

[0089] 5. Based on the established internal support plane object, a finite element calculation model of the members of the internal support structure can be established on the preset interface. Given the support reaction force from the calculation of the retaining piles borne by the internal support structure as a uniformly distributed load, mechanical calculations can be performed on the internal support structure to obtain the evaluation results of the strength, stiffness, and stability of the internal support structure.

[0090] 6. By setting the joint names of the cross braces and inclined braces and the layout spacing of the internal support corbels on the ring beam and other attribute information on the preset interface, a design detail drawing of the internal support plane object with an internal support plane, a corbel plane, and a retaining pile plane as shown in Figure 12 can be established.

[0091] 7. By setting the joint names of the cross braces and inclined braces, the thickness, spacing, and quantity of the stiffening rib plates of the ring beam and other attribute information on the preset interface, a design detail drawing of the internal support plane object with a rib plate plane and a stiffened rib plate plane as shown in Figure 13 can be established.

[0092] XI. The retaining structure design management object is a functional graphic object with the following basic characteristics:

[0093] 1. The retaining structure design management object is a functional graphic object expressed by a rectangular frame and is also a characteristic symbol object. Within its rectangular frame, there are groups of retaining plane layout objects, retaining elevation layout objects, and retaining elevation layout detail objects to achieve the comprehensive management of the retaining structure design.

[0094] 2. The attribute information of the retaining structure design management object includes the attribute information of each component object in the group of retaining elevation layout objects such as the retaining pile elevation object, the foundation pit soil layer elevation object, the internal support elevation object, the pile cap elevation object, the water level line marking object, the full - area uniformly distributed load object, the rectangular uniformly distributed load object, the strip - shaped uniformly distributed load object, and the bottom - sealed concrete elevation object. These attribute information can be modified through the preset interface. The attribute information of the retaining structure design management object also includes the basic information for calculating the retaining structure of the pile cap, such as the safety level for calculating the retaining structure of the foundation pit, the relevant slice calculation width, the horizontal displacement at the bottom of the pit, etc.

[0095] 3. According to relevant foundation pit technical standards or technical specifications, on the preset interface, the earth pressures in the active and passive zones of the retaining structure, the embedment stability, the anti - heave stability, the overall stability, the underground seepage stability, the retaining piles, the internal support structure, the soil reaction force, and the bottom - sealed concrete, etc. can be subjected to corresponding retaining structure calculations, and a calculation book meeting the specification requirements can be automatically generated.

[0096] XII. The bottom - sealed concrete object is a two - dimensional functional graphic object with the following basic characteristics:

[0097] 1. The bottom-sealing concrete object is a feature symbol object expressed in a rectangular manner, used to represent the bottom-sealing concrete of the bearing platform foundation pit, and has attribute information such as the thickness and grade of the bottom-sealing concrete.

[0098] 2. The thickness and grade of the bottom-sealing concrete can be modified on the preset interface to obtain the required bottom-sealing concrete object.

[0099] XIII. The joint object is a two-dimensional functional graphic object with the following basic characteristics:

[0100] 1. The joint object has attribute information such as the joint name, is arranged at the end of the horizontal brace or inclined brace in the internal support plane object, and the horizontal brace or inclined brace is welded into a whole through the joint object with the ring beam.

[0101] 2. First, draw the two-dimensional joint geometric figure, merge it into a block object, and then convert it into a joint object. A parametric joint object can also be constructed, and the required joint object can be obtained by setting parameters on the preset interface.

[0102] 3. First, construct different types of joint objects, store them in the system database, and modify to obtain the required joint object by specifying the joint name on the preset interface.

[0103] 4. As Figure 15 shown, the joint object has multiple displays, such as Figure 15 (a) and Figure 15 (b) shown two types of horizontal brace joints, Figure 15 (c) shown inclined brace joint, Figure 15 (d) shown horizontal brace joint composed of multiple joints assembled, and Figure 15 (e) shown inclined brace joint composed of multiple joints assembled.

[0104] XIV. The internal support corbel object is a two-dimensional functional graphic object with the following basic characteristics:

[0105] 1. The internal support corbel object has attribute information such as the internal support corbel name.

[0106] 2. First, draw the two-dimensional internal support corbel geometric figure, merge it into a block object, and then convert it into the Figure 16 shown internal support corbel object. A parametric internal support corbel object can also be constructed, and the required internal support corbel object can be obtained by setting parameters on the preset interface.

[0107] 3. First, construct different types of internal support corbel objects, store them in the system database, and modify to obtain the required internal support corbel object by specifying the internal support corbel name on the preset interface.

[0108] 15. The rod object is a two-dimensional functional graphic object with the following basic characteristics:

[0109] 1. The rod object is a functional graphic object used to represent steel components such as I-beams, channels, H-shaped steels, steel pipes, etc. It has attribute information such as rod number, rod name, rod type, rod specification, rod material, rod length, rod quantity, display status, etc. These attribute information can be modified through the preset interface to obtain the required rod object.

[0110] 2. Different types of rods need to be described using corresponding steel specifications, such as I40a, 2[36a, I20a, etc. When the rod is a steel pipe, its specifications are the diameter and wall thickness of the steel pipe.

[0111] 3. The display status of the bar object includes Figure 17 (a) The elevation of the bar shown, Figure 17 (b) The plane of the rod and Figure 17 (c) shows the three states of the bar cross section.

[0112] 4. Each member needs to define its corresponding member name. For example, in the inner support plane object, the member name of the ring beam is ring beam, the member name of the diagonal brace is diagonal brace, and the member name of the opposite brace is opposite brace.

[0113] 5. The rod object can be created by forced conversion, that is, first draw a straight line segment representing the centroid axis of the rod, then force it to be converted into a rod object, and then modify the corresponding attribute information through its preset interface to obtain the required rod object.

[0114] 6. The specification of a rod is information that describes its cross-sectional shape and geometric dimensions. For example, by giving the attribute information "I40a spacing is 40mm", it can be indicated that the specification of the rod is a double I40a I-beam with a cross-sectional static spacing of 40mm.

[0115] 16. Cap foundation pit elevation detail object is a two-dimensional functional graphic object with the following basic features:

[0116] 1. The cap foundation pit elevation detail object is a view obtained by cutting the cap foundation pit in the longitudinal or transverse direction, which is used to indicate the state of the cap foundation pit support elevation arrangement. The cap foundation pit elevation detail object records the description of the foundation pit soil layer parameters, the elevation marks of the pile top, water level, the boundary line elevation of each soil layer, the cap bottom elevation, the bottom of the concrete soil cushion layer, the internal support elevation, the internal support corbel, the ring beam section, the soil backfill area, the concrete backfill area and other information.

[0117] 2. The elevation detail drawing object of the pile cap foundation pit has attribute information such as the soil backfill height, the concrete backfill layer height, whether each construction condition is displayed, and the longitudinal or transverse section direction. The installation of each internal support structure, excavation to the bottom of the foundation pit and pouring of the bottom layer of concrete, soil backfill or concrete backfill, and removal of each internal support structure are collectively referred to as a construction condition. These attribute information can be modified on the preset interface, and the display states of the elevation detail drawings of the pile cap foundation pit under different construction conditions are established according to the support elevation layout object group.

[0118] The rapid design method for the support structure of the pile cap foundation pit of the present invention includes the following steps:

[0119] S1. According to the design data of the bridge structure, using the two-dimensional or three-dimensional geometric modeling function of the BIM system, establish the pile cap pile foundation object in the bridge structure as shown in Figure 1 .

[0120] S2. Given the pile cap plane and the static distance from the inner edge of the support pile plane to the edge of the pile cap, first establish a support elevation layout object group through the pile cap pile foundation object. As shown in Figure 2 , the support elevation layout object group includes the support pile elevation object G, the foundation pit soil layer elevation object H, the internal support elevation object S, the pile cap elevation object C, the water level line marking object W, the uniformly distributed load object Q1, the rectangular uniformly distributed load object Q2, the strip uniformly distributed load object Q3, and the bottom sealed concrete elevation object D. Figure 2 The internal support elevation object S in

[0121] includes three internal support structures from top to bottom, namely the first internal support structure, the second internal support structure, and the third internal support structure. Figure 3 Then, establish a support plane layout object group through the pile cap pile foundation object. As shown in

[0122] , the support plane layout object group includes the internal support plane object WL, the pile cap pile foundation plane object T1, and a series of support pile plane objects Gp.

[0123] Finally, establish a support elevation layout detail drawing object and a support structure design management object through the pile cap pile foundation object. Figure 4 As shown in

[0124] , in the support elevation layout detail drawing object, the foundation pit soil layer parameter markings and elevation markings such as the pile top, water level, elevation of each soil layer boundary, elevation of the bottom of the pile cap, and bottom of the concrete cushion are recorded and displayed, and graphic markings such as the internal support contour, soil backfill, and concrete backfill layer are also recorded. Figure 5 As shown in

[0125] The four parts, namely the support elevation layout object group, the support plan layout object group, the support elevation layout detail object, and the support structure design management object established in this step together constitute the initial design scheme for the foundation pit support structure of the bearing platform.

[0126] S3. According to the hydrogeological conditions at the construction site, by modifying the attribute information of the support structure design management object or by editing the relevant objects in the support elevation layout object group, a support elevation layout object group that meets the on-site hydrogeological requirements can be obtained. According to the number of internal support elevations in the support elevation layout object group, an equal number of support plan layout object groups can be obtained through copy or deletion editing methods.

[0127] S4. For each support plan layout object group, by setting the static distance from the inner edge of the support pile in the plane to the edge of the bearing platform plane, a support plan layout object group that meets the requirements of this static distance can be obtained.

[0128] S5. Set the cross-section specifications and layout attribute information of the opposite bracing and inclined bracing on the internal support plane object in each support plan layout object group to obtain the required internal support plane object.

[0129] When the required internal support plane object cannot be obtained by setting attribute information and modifying attribute information, the internal support plane object can be first decomposed into independent member objects; then, the required member objects can be established through drawing and editing methods; finally, the established member objects are merged and forced to be converted into the required internal support plane object. The member objects here include ring beams, opposite bracings, and inclined bracings.

[0130] S6. According to the support elevation layout object group obtained in step S3 and the internal support plane object obtained in step S5, in accordance with the requirements of relevant technical specifications, perform two-dimensional or three-dimensional structural calculations on the internal support structure expressed by the support piles and the internal support plane object in the support structure to obtain structural calculation results such as strength, stiffness, and stability. Then, perform mechanical calculations on the overall stability, embedment stability of the foundation pit support, and anti-heave of the foundation pit support respectively.

[0131] S7. When the mechanical calculation results in step S6 do not meet the requirements of the technical specifications, repeat steps S4 - S6 until mechanical calculation results that meet the requirements of the technical specifications are obtained, and a calculation book is automatically generated.

[0132] S8. According to the support elevation layout object group and each support plan layout object group, set the backfill parameters of concrete or soil related to the demolition condition of the internal support structure, and establish the support elevation layout detail object corresponding to each condition during the whole process from the installation to the demolition of the internal support structure one by one.

[0133] S9. Set the bracket support layout information, corner brace layout information, ring beam stiffener layout information, and adjustment joint layout information for the strut and diagonal brace in each support plane layout object group respectively, and establish the design details of the ring beam, strut, and diagonal brace in each internal support structure; and establish the engineering quantity table of the internal support structure and the retaining piles according to the support elevation layout object group and each support plane layout object group.

[0134] S10. If there are still incomplete local details on the design details of the ring beam, strut, and diagonal brace in each internal support structure, the local details of the design details of the ring beam, strut, and diagonal brace in each internal support structure can be supplemented by using conventional drawing methods, and the supplemented local details are calculated to complete the design details of the required pile cap foundation pit support structure.

Claims

1. A rapid design method for a foundation pit support structure, characterized in that: The following steps are involved: S1. Based on the design data of the bridge structure, use the BIM system to establish the pile foundation object in the bridge structure; S2. Given the static distance from the edge of the cap plane and the inner edge of the support pile plane to the edge of the cap, establish the support facade layout object group, support plane layout object group, support facade layout detail drawing object and support structure design management object through the cap pile foundation object; S3. By modifying the attribute information of the support structure design management object, or by editing the objects in the support facade arrangement object group, a support facade arrangement object group that meets the on-site hydrogeological requirements is obtained; according to the number of internal support facades, an equal number of support plane arrangement object groups are obtained by copying or deleting; S4. By setting the static spacing from the inner edge of the support pile plane to the edge of the cap plane, a support plane arrangement object group that meets the static spacing requirement is obtained; S5. Setting the cross-sectional specifications and layout attribute information of the bracing and the diagonal bracing on the inner support plane object in each support plane layout object group to obtain the required inner support plane object; S6, according to the support facade arrangement object group obtained in step S3 and the inner support plane object obtained in step S5, the inner support structure in the support structure is structurally calculated, and then the overall stability, embedded stability and mechanical calculation of the anti-uplift of the foundation pit support are respectively performed; S7, repeating steps S4-S6 until a mechanical calculation result that meets the requirements of the technical specifications is obtained and a calculation report is generated; S8. According to the support facade layout object group and each support plane layout object group, set the backfill parameters of concrete or soil, and establish the support facade layout detail drawing object corresponding to each working condition from the installation of the inner support structure step by step to the whole process of demolition; S9. In each support plane layout object group, respectively set the corbel support layout information, angle brace layout information, ring beam reinforcement rib layout information and adjustment joint layout information of braces and diagonal braces, and establish the design details of the ring beam, brace and diagonal brace in each internal support structure; and according to the support elevation layout object group and each support plane layout object group, establish the engineering number drawing quantity table of the internal support structure and support piles.

2. The rapid design method for foundation pit support structure according to claim 1 is characterized in that: The following steps are also included: S10. Supplement local details to the design details of the ring beam, brace and diagonal brace of each internal supporting structure to complete the design details of the foundation pit support structure.

3. The rapid design method for foundation pit support structure of a cap according to claim 1 or 2 is characterized in that: The support facade arrangement object group includes support pile facade objects, foundation pit soil layer facade objects, internal support facade objects, pedestal facade objects, water level mark objects, full uniform load objects, rectangular uniform load objects, strip uniform load objects and bottom concrete facade objects.

4. The rapid design method for foundation pit support structure of a cap according to claim 1 or 2 is characterized in that: The support plane layout object group includes an inner support plane object, a cap pile foundation plane object and a series of support pile plane objects.

5. The rapid design method for foundation pit support structure of a cap according to claim 1 or 2 is characterized in that: In step S5, when the required inner support plane object cannot be obtained, the inner support plane object is first decomposed into independent rod objects, and then the required rod objects are established by drawing and editing, and the established rod objects are merged and forcibly converted into the required inner support plane object.

6. The rapid design method for foundation pit support structure of claim 5 is characterized in that: The rod objects include ring beams, braces and diagonal braces.

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