Disclosure of Invention
In order to meet the design requirements of limited underground space conditions of underground transportation hubs in modern building design, such as openness, space effect and the like, and improve the ventilation and lighting conditions, the traditional beam and column system is abandoned.
The core technology of the invention is that when the cover-excavation top-down construction method is adopted, the reserved joints of the inclined columns of each layer are firstly made in a top-down mode, then the splicing sections of the inclined columns of each layer are made in a sequential mode, and the reserved joints of the inclined columns of each layer and the splicing sections of the inclined columns form the fish belly type multi-layer segmented inclined column. The inclination angle of the multilayer subsection batter post is determined before the construction of the batter post splicing section, the construction is greatly simplified, and meanwhile, the fish-bellied batter post symmetrical arrangement mode is more beneficial to natural lighting of an underground structure.
The invention is realized by the following technical scheme:
a construction method of a large fish belly type inclined column structure in underground space comprises the following steps:
1) construction preparation: processing the section steel beam and the inclined column reserved joint in a processing plant according to the design size, and connecting the inclined column reserved joint and the main structure beam into a whole;
2) constructing a cushion layer and an embedded part: performing earth excavation in the cover plate area, and immediately pouring cushion concrete after the foundation pit of the cover plate is excavated and the bottom is cleared; constructing and excavating a foundation serving as an erection support below the inclined column, then paying off and installing a pre-embedded steel plate in the foundation serving as the erection support, connecting the bottoms of the steel plates by using reinforcing steel bars, and pouring concrete;
3) measuring and lofting: modeling the reserved joints of the section steel beams and the inclined columns, calculating the coordinates of the installation joints according to the design coordinates and the elevation of the installation positions, and taking the calculated coordinates of the installation joints as the basis for measuring and paying off after the calculated coordinates of the installation joints are consistent with the coordinates called out by modeling; welding a positioning steel plate at the installation side line of the measurement popup, then installing each layer of inclined column reserved joint, measuring the upper and lower end control points of the inclined column reserved joint after the installation is finished, and manufacturing each layer of inclined column splicing section according to the control points;
4) hoisting the reserved joints of the section steel beams and the inclined columns: installing the inclined column reserved joint to a design position according to the lofting position in the step 3), and processing and installing the section steel beam according to the actual length on site after the inclined column reserved joint is installed;
5) positioning and reinforcing the reserved joints of the section steel beams and the inclined columns: rechecking and finely adjusting the elevation of the top of the section steel beam and the axis, the verticality and the angle of the reserved joint of the inclined column, and performing reinforcement measures after the positioning is completed; after positioning and reinforcing, rechecking the axes and elevations of the reserved joints of the section steel beams and the inclined columns, and entering the next step after no errors exist;
6) construction of the inclined column splicing section: after the main structure is constructed, constructing the splicing sections of the inclined columns by adopting a cover-excavation method; and hoisting the inclined column splicing section to the splicing section position, adjusting the inclined column splicing section to be completely aligned with the inclined column reserved joint by using the reserved limiting clamp plate, and performing full penetration welding after accurate positioning.
As a further improvement of the technical scheme, the reserved joints of the inclined columns and the splicing sections of the inclined columns form a fish belly type multi-layer subsection inclined column.
As a further improvement of the technical scheme, the fish belly type symmetrical arrangement formed by the multilayer subsection batter posts ensures the natural lighting of the underground space to the maximum extent.
As a further improvement of the technical scheme, the multi-layer subsection batter post adopts a construction method combining cover-excavation reverse construction and cover-excavation forward construction: during construction, the reserved joints of the inclined columns of each layer are firstly reversely constructed, and then the splicing sections of the inclined columns of each layer are sequentially constructed.
Considering that the fish belly type batter posts are large in quantity and weight, and loads are applied to each layer of plate, so that the stress of the temporary posts is overlarge; the reserved joints of the inclined columns of each layer are reversely made, and then the splicing sections of the inclined columns of each layer are covered and dug, so that the cross operation in the inclined column splicing process can be reduced, the operation interference between an upper layer and a lower layer in the multilayer splicing process can be reduced, the construction operation surface can be effectively increased, and the engineering quality can be obviously improved.
As a further improvement of the technical scheme, temporary stand columns are arranged between the layers of plates, and temporary support is provided for the main structure before the construction of the inclined column splicing section.
As a further improvement of the technical scheme, a skylight made of transparent materials is arranged between the fish-bellied inclined columns at the top plate, and the purpose is to improve the natural lighting of the underground structure.
As a further improvement of the technical scheme, the earth excavation of the construction cover plate area in the step 2) is carried out for 4m until the earth excavation reaches 2.2m below the top plate, and the rest layers are excavated to 2m below the layer plate; and excavating the cover plate foundation pit to a position close to the substrate by 200 mm.
As a further improvement of the technical scheme, the 'foundation' used as the erection support in the step 2) is 3000mm by 3000mm, the depth is 400mm, and a phi 14@200 reinforcing mesh is arranged inside the foundation; pre-embedding 4 steel plates with the size of 1000mm x 600mm x 16mm at the top of the foundation in advance; and simultaneously, 600mm by 16mm supporting steel plates are embedded in the inclined direction of the inclined column and the direction of the section steel beam.
As a further improvement of the technical scheme, in the step 5) after fine adjustment, the deviation of the elevation of the top of the steel beam is required to be within +/-2 mm, the deviation of the axis of the reserved joint of the inclined column is less than 3mm, and the verticality of the reserved joint of the inclined column is less than 1 mm.
As a further improvement of the above technical solution, the specific operation of hoisting and moving the spliced section of the batter post to the spliced section position in step 6) is to horizontally pull the upper end and the lower end of the spliced section of the batter post respectively by using two hoisting points arranged on the steel beam, slowly unload the lifting hook after moving to the spliced section position, and tighten the horizontal pull ropes at the upper end and the lower end to position the spliced section of the batter post.
As a further improvement of the technical scheme, in the step 6), before the inclined column splicing section is welded, an operation frame needs to be erected according to construction requirements, so that the inclined column splicing section is convenient to install and weld.
As a further improvement of the technical scheme, the section steel beam is fixed by the limiting blocks when the section steel beam and the inclined column reserved joint are welded, the side lines of the steel column and the steel beam are positioned firstly during installation, the bottom of the steel column is positioned by the limiting plates, and finally elevation rechecking is required to be carried out, so that the accuracy of the elevation and the plane position is ensured.
Compared with the prior art, the invention has the beneficial effects that:
1. according to the invention, a coordinate system is established by utilizing CAD (computer-aided design) and the position coordinates of each control point at the top and the bottom of the reserved joint of the batter post are obtained by measuring through a total station, so that the batter post is accurately positioned and lofted, and the projection of each control point at the top of the batter post on the floor is guided onto the template support frame by adopting an optical plummet or a plumb bob to determine the position of the side line of the template, so that the positioning and mounting efficiency of the batter post is improved.
2. The invention adopts a construction method combining cover-excavation reverse-construction and cover-excavation forward-construction, overcomes the defects of narrow construction site, various buildings on the ground at the periphery, complex ground traffic composition and the like, and shortens the construction period.
3. According to the invention, the batter post is designed into a multi-layer sectional form, so that the construction is greatly facilitated, and the safety of engineering construction is improved. Meanwhile, the fish belly type inclined columns are symmetrically arranged, so that sufficient upper space is provided for the underground structure, the using area of the underground space is increased, and natural lighting is increased.
Detailed Description
The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the application, its application, or uses. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
The relative arrangement of the components and steps, the numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present application unless specifically stated otherwise. Meanwhile, it should be understood that the sizes of the respective portions shown in the drawings are not drawn in an actual proportional relationship for the convenience of description. Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate. In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.
In the description of the present application, it should be understood that the terms "first", "second", etc. are used to define the components, and are used only for the convenience of distinguishing the corresponding components, and if not otherwise stated, the terms have no special meaning, and thus, should not be construed as limiting the scope of the present application.
In the description of the present application, it is to be understood that the orientation or positional relationship indicated by the directional terms such as "front, rear, upper, lower, left, right", "lateral, vertical, horizontal" and "top, bottom", etc., are generally based on the orientation or positional relationship shown in the drawings, and are used for convenience of description and simplicity of description only, and in the case of not making a reverse description, these directional terms do not indicate and imply that the device or element being referred to must have a particular orientation or be constructed and operated in a particular orientation, and therefore, should not be considered as limiting the scope of the present application; the terms "inner and outer" refer to the inner and outer relative to the profile of the respective component itself.
The present application is described in detail below with reference to fig. 2.
Fig. 2 is a three-dimensional view of the large fish belly type inclined column structure of the underground space of the invention, which comprises structural steel beams 2 of each layer, temporary upright columns 3, inclined column splicing sections 11 of each layer and reserved joints 12 of inclined columns of each layer besides a main body top plate, a bottom plate and laminated plates of each layer, wherein:
and (3) a section steel beam 2: each layer of section steel beam 2 is connected with the top plate, the bottom plate and each layer of laminate;
the temporary upright post 3: the temporary upright posts 3 are arranged among the top plate, the bottom plate and each layer of laminate;
transparent material 4: the skylight of the transparent material 4 is arranged between the fish belly type inclined columns at the top plate;
inclined column reserved joint 12: welding reserved joints 12 of the inclined columns of each layer with the section steel beams 2 of each layer;
inclined column splicing section 11: and the splicing sections 11 of the inclined columns of each layer and the reserved joints 12 of the inclined columns of each layer are welded to form the fish belly type multi-layer subsection inclined column.
Examples
A construction method of a large fish belly type inclined column structure in underground space comprises the following steps:
the method comprises the following steps:
construction preparation: familiarizing with understanding and examining construction drawings and design files thereof, well preparing construction organization design, processing the section steel beam 2 and the inclined column reserved joint 12 in a professional steel structure processing field, and connecting the inclined column reserved joint 12 and a main structure beam into a whole.
Step two:
constructing a cushion layer and an embedded part:
1. earth excavation: the earth excavation above the main structure cover plate is constructed from west to east by adopting an open excavation method; excavating earth in the construction cover plate area for about 4m until 2.2m below the top plate, and excavating the rest layers to 2m below the layer plate;
2. cushion layer construction: when the excavation of the cover plate foundation pit is close to the foundation by 200mm, manually matching with an excavator to clear the bottom, immediately constructing cushion concrete after clearing the bottom, and pouring C20 concrete into the cushion with the pouring thickness of 150 mm;
3. constructing an inclined column foundation: during construction, an enlarged foundation is constructed below the inclined column, the foundation is 3000mm x 3000mm, the depth is 400mm, a phi 14@200 steel bar mesh is distributed inside the foundation, 4 foundation steel plates are pre-embedded in the top of the foundation in advance, and the size of each steel plate is 1000mm x 600mm x 16 mm; meanwhile, 600mm by 16mm supporting steel plates are pre-embedded in the oblique direction of the oblique columns and the direction of the section steel beams 2 respectively and serve as foundations for erection and support;
4. positioning construction of the embedded steel plate: after foundation excavation is finished, firstly paying off and drawing the position of an embedded steel plate in a foundation by a measuring group, then driving 4 phi 22 steel bars with the length not less than 1m into a soil layer at 4 corner points of the steel plate, then installing the embedded steel plate, measuring and adjusting the whole process of the measuring group in the installation process, ensuring that the elevation error is not greater than 5mm, connecting the bottoms of the steel plates into a whole by adopting the steel bars after the 4 embedded steel plates are installed, and then pouring foundation concrete.
Step three:
measuring and lofting:
1. and (3) coordinate calculation: the method comprises the steps of modeling the section steel beam 2 and the inclined column reserved joint 12, calling any position of the inclined column reserved joint 12, calculating the position of any elevation and the coordinates of the position of the inclined column reserved joint 12 manually, and calculating the coordinates of four point positions at the upper end and the lower end of each mounting joint according to the design coordinates and the mounting position elevation. After the calculated coordinates are completely consistent with the coordinates called out by modeling, the coordinates are used as the basis for measuring and paying off;
2. marking the corner points of the section steel beam 2 or the inclined column reserved joint 12 to be constructed on the cushion layer by a measuring group, measuring the actual cushion layer elevation to determine the temporary supporting height, popping out the mounting side line of the inclined column reserved joint 12 by construction operators according to the axis released by the measuring group by a ruler amount, and welding a positioning steel plate at the mounting side line. After the installation of each layer of inclined column reserved joint 12 is finished, 4 control points are measured at the upper end and the lower end of each layer of inclined column reserved joint 12 respectively, and the inclined column splicing section 11 is manufactured through blanking of a manufacturer according to the actual measurement condition.
Step four:
hoisting each layer of section steel beam 2 and the inclined column reserved joint 12: the batter post is reserved and is connected 12 and adopt 50t truck crane to hoist, reserves the batter post and connects 12 hoist to take horizontal rotation function's ground tank removal instrument on, power adopts 5t hoist engine to pull, and ground tank removal instrument adopts the channel-section steel to do the track, moves according to lofting position, reserves the batter post and connects 12 fortune to the design position and install. And after the inclined column reserved joint 12 is installed, machining the section steel beam 2 according to the actual length on site, and installing by using a crane after machining.
Step five:
and (3) positioning and reinforcing the joints 12 of the section steel beams 2 and the inclined columns: after the inclined column reserved joint 12 is in place, on-site measuring personnel recheck the elevation and the axis of the beam top and the perpendicularity and the angle of the inclined column reserved joint 12 by using a total station, fine adjustment is carried out on the axis of the inclined column reserved joint 12 by adopting a method of matching a crane with manual left-right moving, the axis deviation is ensured to be less than 3mm, fine adjustment is carried out on the elevation of the beam top by adopting a temporary support, the design elevation is finally reached, the deviation of the elevation of the beam top is ensured to be +/-2 mm, and the perpendicularity of the inclined column reserved joint 12 is less than 1 mm. After the inclined column reserved joint 12 is positioned and finished, the inclined column reserved joint 12 needs to be reinforced, an H-shaped steel support column is adopted at the end of the section steel beam 2 to support, and the section steel beam is ensured to be stable and does not shake.
Step six:
and (3) measurement and rechecking: and after the section steel beam 2 and the inclined column reserved joint 12 are reinforced, rechecking the axes and the elevations of the section steel beam 2 and the inclined column reserved joint 12 again by using a total station, and entering the next procedure after the situation that the axes and the elevations are correct is determined.
Step seven:
and (3) constructing an inclined column splicing section 11: after the construction of all main structures in the underground space is completed, the inclined column splicing sections 11 are sequentially constructed.
1. The inclined column splicing section 11 is vertically hoisted by utilizing a preset lifting hook of the upper steel beam;
2. respectively horizontally pulling the upper end and the lower end of the inclined column splicing section 11 by utilizing two lifting points arranged on the upper steel beam, and gradually shifting to the splicing section; the vertical hook portion unloads slowly.
3. The upper end and the lower end of the horizontal pulling rope are tightened, the inclined column splicing section 11 is slowly put in place, the inclined column splicing section 11 is adjusted by means of reserved limiting clamping plates and the like and is completely aligned with the inclined column reserved joint 12, the inclined column reserved joint 12 and the inclined column splicing section 11 are welded through full penetration welding after being accurately positioned, welding quality is guaranteed to be qualified, and 100% of welding seams are detected.
In the seventh step of the present embodiment, an operation frame is set up according to the construction requirements before the welding of the inclined column splicing section 11, which is convenient for the installation and welding of the inclined column splicing section 11. The shaped steel beam 2 is fixed by a limiting block when the shaped steel beam 2 and the inclined column reserved joint 12 are welded, the welded shaped steel beam is transported to the site to be installed, the side lines of the steel column and the shaped steel beam 2 are positioned firstly during installation, the bottom of the steel column is positioned by a limiting plate, and finally elevation rechecking is carried out to ensure that the elevation and the plane position are accurate and correct. Temporary columns 3 are installed between the laminates to provide temporary support for the structure before the construction of the batter post splicing section 12. A skylight made of transparent materials 4 is arranged between the fish belly type inclined columns at the top plate, and the purpose is to naturally collect light of an underground structure.
The construction method of the large fish belly type inclined column structure in the underground space overcomes the defects of narrow construction site, multiple surrounding buildings, complex ground traffic composition and the like, has the advantages of high safety, short construction period, high construction efficiency, low influence on the surrounding environment and the like, and is suitable for engineering development of the current downtown areas of large cities with fierce competition and traffic jam. According to the invention, the reserved joints of the inclined columns of each layer are firstly reversely made, so that the horizontal deformation of the enclosure structure in the construction process is reduced, the engineering quantity of temporary facilities is reduced, and the influence on the surrounding environment is reduced; then, the inclined column splicing sections of each layer are sequentially fabricated, so that the operation interference in the splicing process is reduced, the operation surface is increased, and the construction efficiency is improved; the reserved joints of the inclined columns of all layers and the splicing sections of the inclined columns of all layers form the fish-bellied multi-layer subsection inclined column, and the multi-layer subsection form of the inclined columns facilitates construction and also improves construction safety. The large fish belly type inclined column structure in the underground space constructed by the construction method has the advantages of large underground use space, good natural lighting and good application prospect.
The above-described embodiments are only preferred embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made by one skilled in the art, and any modification, equivalent replacement, improvement and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.