Light steel grating concrete spraying supporting structure for thermal narrow-strip-shaped foundation pit upside-down construction

Abstract

The utility model provides a light steel grating concrete spraying supporting structure for thermal narrow strip type foundation pit upside-down construction, which belongs to the technical field of thermal pipeline construction and comprises a top beam arranged on one side of a retaining wall, a plurality of supporting gratings are arranged on one side of the top beam, and a concrete supporting layer covers the outer sides of the supporting gratings. The supporting grating is connected with a channel steel support; wherein the supporting grids and the channel steel supports form a supporting truss, one channel steel support is arranged every other grid, and one inclined strut is arranged in each supporting grid. According to the utility model, through the innovative upside-down hanging method technology, large-scale mechanical equipment is not depended, the construction process is simplified, and the construction complexity and the labor cost are reduced; accurate supporting can be achieved, and the problem that supporting is insufficient or excessive in a traditional supporting mode is solved; the structure is short in construction period and capable of meeting the requirements for rapid construction and emergency repair of the thermal pipeline foundation pit, disturbance to the surrounding environment is effectively reduced, and construction safety is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to heat pipeline construction technical field, concretely relates to a light -duty steel grating concrete spraying support structure of heat narrow strip type foundation pit inverted method construction. BACKGROUND

[0002] In the heat pipeline construction process, the surrounding soil body usually needs to be grooving treatment, forms narrow strip type foundation pit. However, this kind of foundation pit usually is located in the city high risk area, can bring the significant security risk to the surrounding underground environment. Compared with the traditional large -scale heat foundation pit, the heat pipeline foundation pit of city sensitive area has the small disturbance range, the construction risk is high, the time limit is tight, the timeliness is strong and so on.

[0003] The heat pipeline foundation pit is not paid enough attention traditionally due to its small excavation amount, small grooving depth and width and the like. However, this kind of foundation pit is widely present in the city, and often is located in the traffic dense area or the complex zone of municipal pipeline. Due to the particularity of the environment around the foundation pit, if the support mode is not standard, can cause the foundation pit collapse, structure overturn and the like safety accidents, thereby causing the significant hidden danger to the surrounding environment and personnel safety.

[0004] At present, the support mode of heat pipeline foundation pit mostly refers to the scheme of large -scale building foundation pit engineering, such as wood support, steel sheet pile, reinforced concrete row pile, underground continuous wall, soil nailing wall and the like. However, these traditional support forms have multiple inadaptation problems when applied to heat foundation pit. First, the traditional support mode usually needs large -scale mechanical equipment to cooperate with the construction, and the construction procedure is complicated and the process is complex, the operation is difficult, and the scene requirement is high. Secondly, these support structure construction period is long, is difficult to meet the emergency demand such as repair, rapid replacement and the like commonly seen in heat pipeline construction. Thirdly, due to the unique narrow strip characteristic of heat pipeline foundation pit, when large -scale foundation pit support mode is used, the problems of insufficient support or excessive support are prone to appear, leading to the failure to realize accurate support, causes material waste or the unsatisfactory support effect. Finally, the mechanical operation of traditional support mode can produce the disturbance to the surrounding buildings or underground pipeline, increases the security risk of surrounding facilities, especially in the city high risk area is more prominent.

[0005] In summary, the existing traditional supporting methods have the following problems: a large number of large mechanical equipment is needed, the construction space and conditions are limited, and the operation is difficult, which cannot adapt to the narrow construction space of the heat pipe foundation pit. Due to the need to operate large machinery in a small area, the construction flexibility is poor, and the operation risk may be increased. The construction process of the traditional supporting method is complex, involving multiple process links and operation steps, which increases the construction difficulty and labor cost. Especially in high-risk urban areas, complex processes are more difficult to ensure construction efficiency and safety. The traditional supporting structure usually needs a long construction period, which is difficult to meet the timeliness requirements of emergency tasks such as heat pipe foundation pit repair and rapid replacement. A longer construction period not only affects the project progress, but also may affect the normal operation of the heat pipe network, causing economic losses. Due to the particularity of the heat foundation pit strip, the traditional large foundation pit supporting form is difficult to realize precise supporting, and problems such as over-supporting or insufficient supporting often occur. This not only affects the supporting effect, but also causes material waste and safety hazards. The mechanical operation of the traditional supporting method causes great disturbance to the surrounding environment, especially in high-risk urban areas, which is easy to cause safety risks to the surrounding buildings, underground pipelines and the like. Such disturbance may cause secondary accidents and increase the risk of surrounding facilities. In some cases, the heat pipe foundation pit does not use a supporting structure, or only uses a wooden support for supporting, which has a high construction risk and is easy to cause safety accidents such as collapse or structure overturning. When a large building foundation pit supporting (such as a steel sheet pile, a reinforced concrete pile) is used, the process is complex and the construction period is long: the heat pipe foundation pit uses the supporting method of the traditional large building foundation pit, such as a steel sheet pile, a reinforced concrete pile and the like, the construction process is complex, the period is long, and it is difficult to meet the urgent needs of heat pipe repair and replacement. Practical new type content

[0006] The utility model discloses a light -duty steel grating concrete supporting structure of heat narrow strip type foundation pit inverted hanging method construction that has improved construction and construction efficiency and shortened construction period to solve at least one technical problem in the background art.

[0007] In order to realize the above-mentioned purpose, the utility model adopts the following technical scheme:

[0008] The utility model discloses a light -duty steel grating concrete supporting structure of heat narrow strip type foundation pit inverted hanging method construction, which comprises: the crown beam set up on one side of the retaining wall, a plurality of supporting grating is set up on one side of the crown beam, and the outer side of the supporting grating is covered with a concrete supporting layer.

[0009] Further, the channel steel steel support is composed of two 16a channel steels.

[0010] Furthermore, a support grid is installed every 600mm in the support truss.

[0011] Furthermore, between two adjacent support grids, the two adjacent support grids are connected by bolts by welding connectors onto each support grid.

[0012] Furthermore, the connecting component is an angle steel.

[0013] Furthermore, the anchoring bars of the support grid extend into the capping beam, the capping beam has main reinforcing bars inside and stirrups outside; the connecting main reinforcing bars and connecting stirrups are located outside the anchoring bars.

[0014] The beneficial effects of this utility model are as follows: Through the innovative inverted hanging method, this support structure does not rely on large mechanical equipment, which simplifies the construction process and reduces the complexity of construction and labor costs; the structural design can achieve precise support, avoiding the problems of insufficient or excessive support in traditional support methods; the construction cycle of this structure is short, which can meet the needs of rapid construction and emergency repair of thermal pipeline foundation pits, and effectively reduce the disturbance to the surrounding environment and improve construction safety.

[0015] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of the invention. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a structural diagram of a lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method as described in this embodiment of the utility model.

[0018] Figure 2 This is a structural diagram of the steel truss described in an embodiment of the present utility model.

[0019] Figure 3 This is a structural diagram of the connection between the crown beam and the steel grating as described in an embodiment of this utility model.

[0020] Figure 4 This is a front view structural diagram of the connection between steel gratings according to an embodiment of the present utility model.

[0021] Figure 5 This is a side view of the connection between the steel gratings described in an embodiment of the present invention.

[0022] Figure 6 This is a side view of the connection structure between the steel support and the steel grating as described in an embodiment of this utility model.

[0023] Figure 7 This is a front view of the connection structure between the steel support and the steel grating described in an embodiment of the present utility model.

[0024] Figure 8 This is a side view of the main reinforcement and stirrup structure at the connection between the steel support and the steel grid in an embodiment of this utility model.

[0025] Wherein: 1-retaining wall; 2-capping beam; 3-support grid; 4-concrete support layer; 5-channel steel support; 6-diagonal brace; 7-connecting main reinforcement; 8-connecting stirrup; 9-connector; 10-bolt; 11-welded steel plate; 12-capping beam main reinforcement; 13-capping beam stirrup; 14-anchoring reinforcement. Detailed Implementation

[0026] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0027] It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0028] It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with their meanings in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as here.

[0029] Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the word “comprising” as used in this specification means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or groups thereof.

[0030] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. Furthermore, the described specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of those different embodiments or examples.

[0031] In the description of this specification, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0032] In the description of this specification, the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this technology and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this technology.

[0033] Unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of these terms in this art according to the specific circumstances.

[0034] To facilitate understanding of this utility model, the following description, in conjunction with the accompanying drawings, provides further explanation of specific embodiments. These specific embodiments do not constitute a limitation on the embodiments of this utility model.

[0035] Those skilled in the art should understand that the accompanying drawings are merely schematic diagrams of embodiments, and the components in the drawings are not necessarily essential for implementing this utility model.

[0036] This invention proposes an innovative inverted lightweight steel grating shotcrete support structure, which effectively solves several defects in existing thermal pipeline foundation pit support technologies, especially the problems of strong mechanical dependence, complex processes, long construction cycles, poor support accuracy, and significant environmental disturbance encountered during construction. By applying steel grating shotcrete technology to narrow-strip foundation pit construction, this structure achieves efficient and precise support, simplifying the construction process, significantly shortening the construction period, and avoiding the need for cumbersome large-scale machinery. This novel support structure enables "rapid and convenient construction" in confined spaces and high-risk environments, meeting the special construction needs of thermal pipeline foundation pits and effectively improving construction efficiency and support safety.

[0037] like Figures 1 to 8 As shown in one specific embodiment, a lightweight steel grid shotcrete support structure for thermal narrow strip-type foundation pit inverted construction is provided, comprising: a capping beam 2 set on one side of the retaining wall 1, multiple support grids 3 set on one side of the capping beam 2, and a concrete support layer 4 covering the outside of the support grids 3; the support grids 3 are connected to channel steel supports 5; wherein, the support grids 3 and the channel steel supports 5 constitute a support truss, with one channel steel support 5 set every other grid, and one diagonal brace 6 in each support grid. In this embodiment, the channel steel supports are composed of two 16a channel steels combined, and a support grid is set every 600mm in the support truss. Adjacent support grids are connected by welding connectors 9 to each support grid and then connecting the two adjacent connectors 9 with bolts 10. The connectors 9 can be angle steel. The anchoring steel bars 14 of the support grid extend into the capping beam 2. The capping beam 2 is provided with the main reinforcement bars 12 and the outer side is provided with the stirrup bars 13. The connecting main reinforcement bars 7 and the connecting stirrup bars 8 are located on the outer side of the anchoring steel bars 14.

[0038] Combination Figure 1 , Figure 2As shown, in this embodiment, the retaining wall 1 has a thickness of 360mm and a height not exceeding 1000mm. The capping beam 2 has a thickness of 1000mm, and its height can be adjusted according to site conditions. The support grid 3 is a steel grid, with one steel grid installed every 600mm. Outside the steel grid is a 200mm thick C25 shotcrete support layer 4. The channel steel support 5 is a combination of two 16a channel steels, with one installed every other grid. The diagonal brace 6 is a 10 I-beam, with one installed per grid. The diameter of the connecting main reinforcement 7 is 16mm. The diameter of the connecting stirrups 8 is 12mm, spaced 200mm apart. The connector 9 is an angle steel, welded to the channel steel support, and adjacent angle steels are connected by bolts 10, using M20 bolts. The connection between the channel steel supports is achieved by welding steel plates 11. The diameter of the capping beam main reinforcement 12 is 20mm. The diameter of the cap beam stirrups 13 is 12mm, and the spacing is 300mm. The diameter of the anchoring steel bars 14 is 14mm, the spacing is 800mm, and the anchorage length in the beam is 800mm.

[0039] In summary, this utility model proposes a lightweight support structure suitable for narrow-strip foundation pits in urban pipelines. By constructing retaining walls and capping beams before excavation, combined with vertical shaft steel grating and shotcrete support, efficient and safe lightweight support is achieved. This support method is lightweight and easy to construct, ensuring foundation pit stability while reducing the space occupied by the support structure and soil disturbance, making it particularly suitable for long and narrow foundation pits. The support structure of this utility model consists of retaining walls, capping beams, lightweight vertical shaft steel grating, shotcrete layers, steel supports, and diagonal braces. An inverted hanging method is used in the construction sequence to ensure the integrity and stability of the support. The retaining wall, as the outer support structure of the foundation pit, is a cast-in-place L-shaped or T-shaped lightweight reinforced concrete wall. The retaining wall is set on the outer side of the upper excavation edge of the foundation pit, serving to limit the slippage of the surrounding soil, as shown in the attached figure. Figure 1As shown. The capping beam is located at the top edge of the excavation pit, serving as the top connecting component of the support structure. The capping beam has a cross-sectional dimension of 1000mm wide and 600mm high, with internal reinforcement using 20mm main bars to ensure bending resistance. It is integrated with the retaining wall and the subsequent steel grating shotcrete support structure to form a unified lightweight support system. The capping beam also uses C30 concrete. The support grating, a steel grating, is the core support unit of this system. It uses standard 250mm × 300mm steel grating units made of 6mm thick high-strength Q235 steel. The units are connected by M20 bolts, with a transverse spacing of 600mm and a longitudinal spacing of 600mm. The steel grating is installed to the excavation pit wall using an inverted method, with the bottom end inserted approximately 200mm into the bottom soil of the pit to ensure the stability of the support structure during construction. Shotcrete covers the surface of the steel grating as the main concrete support layer, with a thickness controlled at 200mm, using C25 concrete to form a lightweight support surface with compressive and shear strength. Shotcrete application is simple and efficient, further improving the construction efficiency of the inverted lightweight support structure. The steel support structure uses two 16a channel steels combined to enhance the stability of the engineering structure. Three supports are installed horizontally, and one is installed every other grid in the vertical direction. Diagonal bracing using 10-I-beams is installed at the right-angle corners of the steel truss, one per grid. This forms a space truss, which effectively increases the rigidity of the structure.

[0040] This invention employs an inverted construction method, combining the pre-construction of the retaining wall and capping beam with steel grating shotcrete support, achieving flexible and efficient construction. The specific construction steps are as follows:

[0041] (1) Construction of retaining walls and capping beams: Before the excavation of the foundation pit, retaining walls are set up around the perimeter of the foundation pit, and capping beams are installed on the top of the foundation pit. The construction of retaining walls and capping beams is convenient and lightweight, and the support layout of the upper structure of the foundation pit can be completed quickly.

[0042] (2) Segmented excavation of the foundation pit: After the construction of the retaining wall and the capping beam is completed, the foundation pit will be excavated in segments, each segment being about 0.6 meters long, in order to reduce the exposure time and maintain the stability of the upper support.

[0043] (3) Inverted installation of steel grating: The steel grating is suspended and installed on the side wall of the excavated foundation pit using the inverted method. 250mm×300mm standard steel grating units are installed vertically along the foundation pit wall, and the bottom of the grating is embedded in the soil at the bottom of the foundation pit to ensure the stability of the support structure during the inverted installation process.

[0044] (4) Shotcrete construction: Shotcrete work is carried out after the steel grating is installed. The spray thickness is controlled at 200mm to ensure that the shotcrete layer is tightly attached to the surface of the steel grating and forms a continuous support structure.

[0045] This invention employs an inverted hanging construction technique to address the space constraints of narrow thermal foundation pits, ensuring stable installation of the support structure within confined construction environments. Through this method, the steel grating and shotcrete can be precisely installed onto the pit sidewalls, avoiding the installation difficulties and inaccuracies associated with traditional support methods in narrow pits. The steel grating, as the core unit of this invention's support structure, features a lightweight design, facilitating installation within narrow thermal foundation pits. The lightweight steel grating support structure meets the space requirements of narrow pits. The integrated design of the capping beam and retaining wall effectively supports the narrow thermal foundation pit, preventing soil slippage or deformation and avoiding insufficient or excessive support. The combination of the capping beam and retaining wall provides a more stable support foundation within limited space, improving the overall structure's bending resistance and stability. Covering the steel grating surface with shotcrete forms a continuous and stable support layer, effectively enhancing the compressive and shear strength of the support system and ensuring the safety of the narrow thermal foundation pit during construction and use. Furthermore, the shotcrete construction process is simple and efficient, helping to shorten the construction cycle and meet the rapid construction needs of heating pipeline foundation pits. By using the inverted hanging method, this invention significantly simplifies the construction process and reduces reliance on traditional large-scale machinery. During the construction of narrow-strip heating pipeline foundation pits, it minimizes disturbance to surrounding buildings, underground pipelines, and other facilities, effectively reducing construction risks and enabling safe construction in high-risk urban areas.

[0046] Compared with existing technologies, the inverted lightweight support structure of this utility model has significant advantages in solving the problem of thermal narrow-strip foundation pit support. Existing technologies, such as commonly used large-scale building foundation pit support structures, such as timber supports, sheet piles, and concrete piles, while providing strong support, are difficult to implement precisely in the confined space of narrow-strip foundation pits. Furthermore, the construction process is complex, the construction period is long, the construction risk is high, and it often relies on large machinery, increasing disturbance to the surrounding environment.

[0047] This invention utilizes an inverted construction method, combining the pre-construction of retaining walls and capping beams with lightweight steel grating and shotcrete support. This successfully solves the problems of inaccurate support and complex construction associated with traditional support methods in narrow foundation pits. The inverted method not only simplifies the construction process but also reduces reliance on large machinery, making construction more efficient and safer. The use of lightweight steel grating further reduces structural weight, adapting to the construction needs of confined spaces. Simultaneously, its combination with the shotcrete layer provides high compressive and shear strength, ensuring the stability of the foundation pit.

[0048] Therefore, compared with the prior art, this utility model not only has significant advantages in construction efficiency, support precision and stability, but also effectively reduces construction risks and disturbance to the surrounding environment, and has broad application prospects in complex urban environments.

[0049] Although the specific embodiments of the present utility model have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present utility model. Those skilled in the art should understand that, based on the technical solutions disclosed in the present utility model, all modifications or variations that can be made by those skilled in the art without creative effort should be included within the scope of protection of the present utility model.

Claims

1. A lightweight steel grating shotcrete support structure for construction using the thermally-driven narrow strip inverted foundation pit method, characterized in that, include: A capping beam is installed on one side of the retaining wall, and multiple support grids are installed on one side of the capping beam. The support grids are covered with a concrete support layer. The support grids are connected to channel steel supports. The support grids and channel steel supports constitute a support truss. One channel steel support is installed every other grid, and each support grid has a diagonal brace.

2. The lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method according to claim 1, characterized in that, The channel steel support is composed of two 16a channel steels combined together.

3. The lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method according to claim 1, characterized in that, In the support truss, a support grid is installed every 600mm.

4. The lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method according to claim 1, characterized in that, Between two adjacent support grids, the two adjacent support grids are connected by bolts by welding connectors onto each support grid.

5. The lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method according to claim 4, characterized in that, The connector is an angle steel.

6. The lightweight steel grid shotcrete support structure constructed using the thermal narrow strip type inverted foundation pit method according to claim 1, characterized in that, The anchoring bars of the support grid extend into the capping beam. The capping beam has main reinforcement bars inside and stirrups outside. The connecting main reinforcement bars and connecting stirrups are located outside the anchoring bars.

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