Box culvert construction process

Abstract

According to the box culvert construction technology, an electric power pipe gallery can be reinforced and supported, and deformation of the electric power pipe gallery during construction of a lower box culvert is avoided.

Description

Technical Field

[0002] This invention belongs to the field of building construction, and particularly relates to the construction of underground box culverts. Background Technology

[0003] A box culvert is a culvert constructed with reinforced concrete box-shaped pipe sections. Box culverts typically consist of one or more square or rectangular cross sections and are generally made of reinforced concrete or masonry, although reinforced concrete is more widely used. Box culverts are used when the span is less than 4m. For pipe culverts, reinforced concrete box culverts are a cheaper alternative. The piers, abutments, and upper and lower slabs are all cast in the same manner, so they are widely used in modern construction.

[0004] Due to the current sophistication of urban infrastructure, the construction area of ​​new box culverts often interferes with existing facilities. When encountering concrete pipeline facilities such as power utility tunnels, improper construction can easily lead to excessive subsidence and even cracking of the tunnel itself. Therefore, a new construction technique is needed to address these construction challenges. Summary of the Invention

[0005] The purpose of this invention is to provide a box culvert construction process to solve the technical problem that the overhead pipe gallery is prone to breakage, collapse or damage due to lack of support during box culvert construction.

[0006] To solve the above-mentioned technical problems, the specific technical solution of the present invention is as follows: A box culvert construction process, characterized by the following construction steps: Step 1: Measure and lay out the lines, excavate the original soil layer at the location of the power utility tunnel, down to the bottom of the power utility tunnel, and retain the core soil directly below the power utility tunnel; Step 2: Lay support beams above the power utility tunnel, install Bailey bridge beams on the support beams, bolt scissor braces between the Bailey bridge beams, and lay transverse load-bearing beams on top of the Bailey bridge beams; Step 3: Drill installation holes in the original soil layer below the power utility tunnel using a drilling machine, insert the lower support beam into the installation holes, and connect the lower support beam to the corresponding transverse load-bearing beam with a pair of threaded steel bars. The threaded steel bars are located on both sides of the power utility tunnel, and initial prestress is applied to the threaded steel bars. Step 4: Install and attach concrete strain gauges on the power utility tunnel; Step 5: After all the lower support beams have been installed, use jacks to apply prestress to the threaded steel according to the calculated values; Step 6: Excavate the original soil layer below the power utility tunnel to form a construction pit, and reinforce the slope of the pit. Step 7: After constructing the main body of the box culvert, use foamed concrete to backfill the gap between the power utility tunnel and the main body of the box culvert.

[0007] Furthermore, in step 1, only the original soil layers at the top and sides of the power utility tunnel are excavated to expose the bottom of the straight wall, while the core soil directly below the power utility tunnel is retained.

[0008] Furthermore, in step 5, when applying force with jacks, concrete strain gauges are used to monitor the strain of the power utility tunnel after being subjected to force, as well as surface cracks.

[0009] Furthermore, in step 3, the installation holes and lower support beams in the lower middle part of the power utility tunnel are constructed first, and then the installation holes and lower support beams on both sides are constructed simultaneously.

[0010] The technical solution of the present invention has the following advantages: 1. It can support the power utility tunnel while preserving the core soil, thus avoiding deformation of the power utility tunnel during the construction of the box culvert below.

[0011] 2. The construction period is short, and there is no additional earthwork excavation. Attached Figure Description

[0012] Figure 1 This is a structural diagram of the construction design of the present invention; Figure 2 This is a schematic diagram of the original soil state structure of the pipe gallery in section AA of the present invention; Figure 3 This is a schematic diagram of the excavation construction structure above the pipe gallery in section AA of the present invention; Figure 4 This is a schematic diagram of the construction structure of the lower support beam in the BB section of the present invention; Figure 5 This is a schematic diagram of the completed construction of the lower support beam in the BB section of the present invention; Figure 6 This is a schematic diagram of the tensioning sequence during the construction of the lower support beam; Figure 7 This is a schematic diagram of the slope opening structure of the present invention; Figure 8 This is a schematic diagram of the completed construction of the box culvert of the present invention; Figure 9 This is a schematic diagram of the concrete filling under the pipe gallery after the main body of the box culvert of the present invention has been completed. Detailed Implementation

[0013] To better understand the purpose, structure, and function of this invention, the technical solution of this invention will be described in further detail below with reference to the accompanying drawings.

[0014] like Figures 1-9 As shown, a box culvert construction process of the present invention includes the following construction steps: Step 1: Measure and lay out the lines, excavate the original soil layer 10 located at the power utility tunnel 2, down to the bottom of the power utility tunnel 2, and retain the core soil directly below the power utility tunnel 2; Step 2: Lay support beams 4 above the power pipe gallery 2, install Bailey beams 6 on the support beams 4, bolt scissor braces 11 between the Bailey beams 6, and lay transverse load-bearing beams 5 on the top of the Bailey beams 6; Step 3: Drill installation holes 13 in the original soil layer 10 below the power utility tunnel 2 using a drilling machine, insert the lower support beam 3 into the installation hole 13, and connect the lower support beam 3 to the corresponding transverse load-bearing beam 5 with a pair of threaded steel bars 7. The threaded steel bars 7 are located on both sides of the power utility tunnel 2, and initial prestress is applied to the threaded steel bars 7. Step 4: Install and attach concrete strain gauges on power utility tunnel 2; Step 5: After all the lower support beams 3 are installed, use jacks 8 to apply prestress to the threaded steel bars 7 according to the calculated values; Step 6: Excavate the original soil layer 10 below the power pipeline corridor 2 to form the construction pit 9, and reinforce the slope of the pit 9; Step 7: After constructing the main body 1 of the box culvert, use foamed concrete 12 to backfill the gap between the power utility tunnel 2 and the main body 1 of the box culvert.

[0015] In practice, in step 1, only the original soil layer 10 at the top and sides of the power utility tunnel 2 is excavated to expose the bottom of the vertical wall, while retaining the core soil directly below the power utility tunnel 2. The excavation of the original soil layer 10 does not exceed 30cm below the bottom elevation of the power utility tunnel 2.

[0016] In practice, in step 3, such as Figure 4 As shown, the installation holes 13 and lower support beams 3 in the lower middle part of the power utility tunnel 2 are constructed first, and then the installation holes 13 and lower support beams 3 on both sides are constructed simultaneously.

[0017] Specifically, during construction, the installation hole 13 in the lower middle part of the power pipe gallery 2 is first drilled using a drilling machine. After drilling, the lower support beam 3 is placed in the gallery. Then, the lower support beam 3 is connected to the corresponding transverse load-bearing beam 5 with a pair of threaded steel bars 7. The initial prestress is applied to the threaded steel bars 7 using a jack 8. This step is repeated until all the lower support beams 3 are constructed (as shown in Figure 5).

[0018] Specifically, the construction sequence of the lower support beam 3 is as follows: Figure 6 As shown, first drill holes for the lower support beam 3 in sequence numbers ① and ②, then drill holes for the lower support beam 3 in sequence numbers ③ and ④, then drill holes for the lower support beam 3 in sequence numbers ⑤ and ⑥, and so on, until the construction of lower support beam 3 in sequence numbers ⑨ and ⑩ is completed.

[0019] It is worth noting that during the construction of step 3, the mounting holes 13 are only drilled when the corresponding lower support beam 3 is installed, and all the mounting holes 13 cannot be constructed at once.

[0020] In actual operation, in step 5, when the force is applied by jack 8, the strain of the power utility tunnel after being subjected to force is monitored by concrete strain gauges, as well as surface cracks.

[0021] Specifically, in step 7, it is not necessary to remove the lower support beam 3 when constructing foamed concrete 12. After the foamed concrete 12 reaches the design strength, the Bailey beam 6 is removed.

[0022] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A box culvert construction technique, characterized in that, The construction steps include the following: Step 1: Measure and lay out the lines, excavate the original soil layer (10) located at the power utility tunnel (2) until below the bottom plate of the power utility tunnel (2), and retain the core soil directly below the power utility tunnel (2); Step 2: Lay a support beam (4) above the power pipe gallery (2), install a Bailey beam (6) on the support beam (4), bolt scissor braces (11) between the Bailey beams (6), and lay a transverse load-bearing beam (5) on the top of the Bailey beam (6). Step 3: Drill installation holes (13) in the original soil layer (10) below the power utility tunnel (2) using a drilling machine, insert the lower support beam (3) into the installation hole (13), connect the lower support beam (3) to the corresponding transverse load-bearing beam (5) with a pair of threaded steel bars (7), the threaded steel bars (7) are located on both sides of the power utility tunnel (2), and apply initial prestress to the threaded steel bars (7); Step 4: Install and attach concrete strain gauges on the power utility tunnel (2); Step 5: After all the lower support beams (3) are installed, use jacks (8) to apply prestress to the threaded steel (7) according to the calculated value; Step 6: Excavate the original soil layer (10) below the power pipe gallery (2) to form a construction pit (9), and reinforce the slope of the pit (9); Step 7: After constructing the main body (1) of the box culvert, use foamed concrete (12) to backfill the gap between the power utility tunnel (2) and the main body (1) of the box culvert.

2. The box culvert construction process according to claim 1, characterized in that, In step 1, only the original soil layer (10) on the top and sides of the power utility tunnel (2) is excavated to expose the bottom of the straight wall and retain the core soil directly below the power utility tunnel (2).

3. The box culvert construction process according to claim 2, characterized in that, In step 5, when the force is applied by the jack (8), the strain of the power pipe gallery after being subjected to force and the surface cracks are monitored by the concrete strain gauge.

4. The box culvert construction process according to claim 3, characterized in that, In step 3, the installation holes (13) and lower support beams (3) in the lower middle part of the power pipe gallery (2) are constructed first, and then the installation holes (13) and lower support beams (3) on both sides are constructed simultaneously.

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