BIM (Building Information Modeling)-based underground pipeline semi-excavation pipe jacking method under complex environmental conditions

Abstract

The invention relates to a BIM (Building Information Modeling)-based underground pipeline semi-excavation pipe jacking method under complex environmental conditions. The method comprises the following steps: constructing a BIM three-dimensional model of a construction area; the positions and sizes of new pipeline construction areas are determined in the BIM three-dimensional model according to the positions of buildings around the planned new pipeline and existing pipelines, and every two adjacent new pipeline construction areas are separated by the existing pipelines transversely penetrating through the planned new pipeline; construction of a supporting system is conducted in the new pipeline construction area, and the supporting system is constructed along the edge of the new pipeline construction area and defines a closed area; earthwork is excavated in a closed area formed by the supporting system to form a foundation pit, and the depth of the foundation pit is the top depth of the planned new pipeline; and in the closed area formed by the supporting system, the working well is constructed at one end, the receiving well is constructed at the other end, and pipe jacking construction is conducted in the closed area formed by the supporting system. According to the method, buildings around the construction area can be effectively protected, and normal construction of new pipelines can be guaranteed.

Description

Technical Field

[0001] The invention relates to an underground pipeline construction technology, in particular to a semi-excavation pipe jacking method for underground pipelines under complex environmental conditions based on BIM. Background Art

[0002] In urban renewal and reconstruction construction, the original urban underground drainage pipeline network can no longer meet its basic functions and must be updated and reconstructed. It often needs to be carried out in existing building areas, especially in old urban areas where the buildings are old and the distance between buildings is small. Since the pipeline construction area is too close to important buildings such as surrounding residential buildings, if large excavation is adopted, the water and soil stability of the construction area cannot be guaranteed due to the existence of underground quicksand layers, which will cause deformation of the foundations of surrounding residential buildings and other buildings, affecting the safety of surrounding buildings; if steel sheet pile support is used, the support structure cannot be closed due to the complexity of underground pipelines and the inability to cut and relocate passing pipelines. Even if grouting technology is used, it is difficult to achieve the expected water-stopping curtain effect. The safety of residential buildings will still be affected by soil erosion after excavation. The use of underground continuous wall support is also difficult to achieve due to the influence of existing pipelines, and the cost is relatively high.

[0003] Therefore, a method for underground pipeline construction is urgently needed while ensuring the safety of adjacent residential buildings. Summary of the invention

[0004] The purpose of the present invention is to provide a semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM, so as to solve the current problem of construction difficulties of underground pipelines near residential buildings.

[0005] The present invention is implemented as follows: a semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM, comprising the following steps.

[0006] Step 1: Use modeling software to build a BIM 3D model of the construction area. The BIM 3D model includes buildings and existing pipelines around the construction area.

[0007] Step 2: Determine the location and size of the new pipeline construction area in the BIM three-dimensional model based on the locations of the buildings and existing pipelines around the planned new pipeline. The new pipeline construction area extends along the length of the planned new pipeline, and two adjacent new pipeline construction areas are separated by the existing pipeline that crosses the planned new pipeline.

[0008] Step 3: Construct the support system in the new pipeline construction area determined in step 2. The support system is constructed along the edge of the new pipeline construction area and encloses a closed area.

[0009] Step 4: Excavate the earth in the closed area formed by the support system to form a foundation pit. The depth of the foundation pit is the top depth of the planned new pipeline, and the top of the pipeline is exposed during the subsequent jacking construction.

[0010] Step 5: In the closed area formed by the support system, construct a working well at one end and a receiving well at the other end, install the jacking equipment and machine head in the working well, and then carry out the jacking construction in the closed area formed by the support system.

[0011] The support system is an SMW method pile, a cap beam is cast on the top of the SMW method pile, and support rods are set between the cap beams on both sides of the new pipeline to be constructed.

[0012] In step five, the pipe segment is hoisted into the working well by the lifting equipment, and the pipe segment is pushed forward by the pipe jacking equipment. After the pipe segment is pushed into place, the pipe jacking equipment retreats and installs the subsequent pipe segment. The jacking and subsequent pipe segment installation are repeated until the working well is connected with the receiving well.

[0013] The method also includes step six: connecting the new pipeline sections.

[0014] In step six, the working well / receiving well at the end of one of the two adjacent new pipeline construction areas is used as the working well in this step, and the working well / receiving well at the end of the other new pipeline construction area is used as the receiving well in this step, and pipe jacking construction is carried out to connect the two adjacent new pipeline construction areas.

[0015] In different new pipeline construction areas, pipe jacking construction is carried out in the same direction. In step six, the position and direction of the pipe jacking device and the machine head are exchanged in the working pit.

[0016] In step 2, the distance between the edge of the new pipeline construction area and the foundation edge of the surrounding buildings is greater than or equal to 2 meters.

[0017] Dewatering wells are set up in the closed area formed by the support system, and dewatering is carried out before foundation pit excavation. Monitoring wells are set up around the closed area formed by the support system, and the groundwater level is tested at any time during construction.

[0018] After the construction of the new pipeline is completed, the foundation pit will be backfilled, and the piles will be pulled out after the support poles are removed.

[0019] The present invention plans the construction area based on BIM, avoids existing pipelines that cross the construction area, adopts a support system to support the new pipeline construction area, and performs semi-excavation jacking construction in a closed area surrounded by the support system. Under the protection of the support system, the water and soil stability around the construction area is guaranteed, the impact of pipeline construction in the new pipeline construction area on the surrounding building foundations is reduced, and the deformation of the surrounding building foundations can be effectively prevented. At the same time, the support system forms a closed water-stop curtain to ensure the construction safety in the new pipeline construction area.

[0020] The present invention adopts semi-excavation jacking construction, which reduces the amount of excavation and the imbalance of the forces on the inner and outer sides of the support system, thereby improving the stability of the support system. At the same time, since the top of the pipeline is exposed during the semi-excavation jacking process, it is convenient to intuitively control the jacking construction process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the new pipeline construction area of ​​the present invention.

[0022] Figure 2 It is a top view of the new pipeline construction area of ​​the present invention.

[0023] Figure 3 It is a schematic diagram of the new pipeline construction area and the existing pipeline of the present invention.

[0024] In the figure: 1. New pipeline; 2. Support system; 3. Foundation pit; 4. Building foundation; 5. Power shaft; 6. Working shaft; 7. Receiving shaft; 8. Jack; 9. Pressure divider ring; 10. Machine head; 11. Existing pipeline; 2-1. Mixing pile; 2-2. Crown beam; 2-3. Strut; 2-4. I-beam. DETAILED DESCRIPTION

[0025] The specific implementation of the present invention will be described below in conjunction with the accompanying drawings.

[0026] like Figure 1 , Figure 2 As shown, the semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM of the present invention is a construction technology for underground pipelines near existing residential buildings under complex geological conditions, and specifically includes the following steps.

[0027] Step 1: Use modeling software to build a BIM three-dimensional model of the construction area. The BIM three-dimensional model includes the construction area and surrounding buildings and existing pipelines 11.

[0028] According to the existing data, drawings, and on-site survey and mapping, the location, depth, direction and other data of the construction area and surrounding buildings, pipelines, etc. are collected, and the BIM three-dimensional model is drawn in the modeling software based on the collected data. Existing pipelines 11 include water pipes, gas, heating, power pipelines, etc. The BIM three-dimensional model is analyzed to mark important buildings, important existing pipelines 11, and existing pipelines 11 crossing the construction area.

[0029] Step 2: In the BIM three-dimensional model, the location and size of the construction area of ​​the new pipeline 1 are determined according to the locations of the buildings around the planned new pipeline 1 and the existing pipeline 11. The construction area of ​​the new pipeline 1 extends along the length of the planned new pipeline 1, and two adjacent new pipeline 1 construction areas are separated by the existing pipeline 11 that crosses the planned new pipeline 1.

[0030] The construction area of ​​the new pipeline 1 needs to avoid important buildings, important existing pipelines 11, and existing pipelines 11 that cross the construction area. The new pipeline 1 is generally constructed along the edge of the existing building foundation 4. When the important existing pipeline 11 is laid in the same direction as the new pipeline 1, the position and spacing relationship between the building foundation 4 and the existing pipeline 11 should be considered. When the distance between the existing pipeline 11 and the building foundation 4 is large, consider constructing the new pipeline 1 between the building foundation 4 and the existing pipeline 11; when the distance between the existing pipeline 11 and the building foundation 4 is small, consider constructing the new pipeline 1 on the outside of the existing pipeline 11; when the distance between the existing pipeline 11 and the building foundation 4 on both sides does not meet the requirements for the construction of the new pipeline 1, consider dismantling the existing pipeline 11. If Figure 1 In the embodiment, the distance between the existing power well 5 and the building foundation 4 is large, so the construction of the new pipeline 1 can be carried out. When the distance between the power well 5 and the building foundation 4 is small, making it impossible to construct the new pipeline 1, it is possible to consider dismantling the existing power well 5 first and then rebuilding it.

[0031] It should be noted that the distance between the edge of the construction area of ​​the new pipeline 1 and the edge of the foundation of the surrounding buildings should be greater than or equal to 2 meters. When the construction area of ​​the new pipeline 1 is too close to the building foundation 4, the construction of the support system 2 will have a certain impact on the building foundation 4.

[0032] When the existing pipeline 11 crosses the construction area of ​​the new pipeline 1, if the existing pipeline 11 is an abandoned pipeline, the existing pipeline 11 can be dismantled first. If the existing pipeline 11 is an important pipeline, the construction area of ​​the new pipeline 1 should avoid the existing pipeline 11. The construction area of ​​the new pipeline 1 is divided into two sections at this part. Figure 3 shown.

[0033] Step 3: construct the support system 2 in the new pipeline 1 construction area determined in step 2. The support system 2 is constructed along the edge of the new pipeline 1 construction area and encloses a closed area.

[0034] The support system 2 is an SMW pile, a cap beam 2-2 is cast on the top of the SMW pile, and a support rod 2-3 is arranged between the cap beams 2-2 on both sides of the new pipeline 1 to be constructed.

[0035] Support system 2 uses a steel-cement soil mixing wall, with I-beam 2-4 inserted inside, reinforced concrete crown beam 2-2 set on the top, and support rods 2-3 are set at intervals along the direction of the new pipeline 1. The two sections of support rod 2-3 are connected to the crown beam 2-2. The insertion of the steel should be carried out within 30 minutes after the construction of the mixing pile 2-1 is completed. Its straightness must be checked before insertion. If there is a welded joint, the quality of the weld of the steel joint must meet the design and specification requirements. The insertion of the steel adopts a positioning guide frame, and two theodolites are used to check the verticality of the steel insertion in both directions. After the steel is inserted in place, the elevation of the top of the steel is controlled by the hanging component, and the inserted steel is connected to prevent the displacement of the steel caused by subsequent construction. The steel should be inserted by self-weight, or it can be sunk into place with the help of auxiliary means such as a vibrating hammer with hydraulic clamps. It is strictly forbidden to insert it by repeatedly lifting the steel and loosening the hook. If the vibrating hammer sinking process is used, the impact on the area close to the existing buildings (structures) must be considered. After the support piles are installed, the excavation and pipe jacking construction of foundation pit 3 can only be carried out after the steel-cement soil mixing wall reaches the specified curing time and design indicators. During the excavation and pipe jacking construction of foundation pit 3, the next step of foundation pit 3 construction can only be carried out after the corresponding horizontal support system reaches the specified curing time and design indicators.

[0036] The cast-in-place reinforced concrete crown beam 2-2 is constructed by pouring it continuously at one time, without leaving construction joints, and it must be smoothed as it is poured to ensure a smooth surface. During the pouring of concrete, it must be ensured that the thickness of the concrete protective layer of the steel bars meets the design requirements.

[0037] Since the existing pipeline 11 crossing the construction area of ​​the new pipeline 1 is avoided during the construction of the support system 2, the support system 2 encloses a long rectangular area, and the closed water-stop curtain forms an effective support and waterproof structure to ensure the stability of soil and water in the construction area. That is, it protects nearby important buildings and existing pipelines, and at the same time reduces the impact of the failure of the water-stop curtain to close on the pipeline construction area, ensuring normal construction in the support system 2 area.

[0038] A dewatering well is set up in the closed area formed by the support system 2, and dewatering is carried out before the excavation of the foundation pit 3. The dewatering of the foundation pit 3 starts 15 to 20 days before the excavation of the foundation pit 3, and a small-flow high-lift pumping machine is used. The dewatering speed is controlled during the dewatering process to avoid rapid pumping to bring out fine particles in the water layer.

[0039] Monitoring wells are set around the closed area formed by the support system 2 to detect the groundwater level at any time during construction.

[0040] Step 4: excavate the earth in the closed area formed by the support system 2 to form a foundation pit 3. The depth of the foundation pit 3 is the top depth of the planned new pipeline 1, and the top of the pipeline is exposed during the subsequent jacking construction.

[0041] Excavate the top part of the earthwork to facilitate the subsequent pipe jacking construction. At the same time, avoid the foundation pit 3 being too deep. If the foundation pit 3 is too deep, the pressure generated by the quicksand layer outside the support system 2 on the support system 2 will damage or deform the support system 2. For the part below the foundation pit 3, since there are soil layers inside and outside the support system 2, the forces on both sides of the support system 2 are balanced, ensuring the stability and reliability of the support system 2.

[0042] Step 5: In the closed area formed by the support system 2, a working well 6 is constructed at one end and a receiving well 7 is constructed at the other end, a pipe jacking equipment and a machine head 10 are installed in the working well 6, and then pipe jacking construction is carried out in the closed area formed by the support system 2.

[0043] Pipe jacking construction can avoid quicksand phenomenon in foundation pit 3 caused by large excavation or steel sheet pile extraction, thereby preventing the foundation of residential buildings from sinking and affecting the safety of residential buildings.

[0044] The working well 6 and the receiving well 7 are concrete structures. The depths of the working well 6 and the receiving well 7 are greater than the depth of the new pipeline 1. A jack 8, a pressure dividing ring 9 and a machine head 10 are installed in the working well 6. The machine head 10 is driven by the jack 8 to pass through the wall of the working well 6. The jack 8 retreats and the pipe section is hoisted into the working well 6 by the lifting equipment. The pipe section is pushed in by the jacking equipment. After the pipe section is pushed in place, the jacking equipment retreats and the subsequent pipe section is installed. The jacking and subsequent pipe section installation are repeated until the working well 6 is connected to the receiving well 7.

[0045] At this point, the construction of each section of the new pipeline 1 construction area is completed, and subsequently the construction areas of each section of the new pipeline 1 need to be connected to each other.

[0046] Step 6: Connect each section of the new pipeline 1.

[0047] The working well 6 / receiving well 7 at the end of one of the two adjacent new pipeline 1 construction areas is used as the working well 6 in this step, and the working well 6 / receiving well 7 at the end of the other new pipeline 1 construction area is used as the receiving well 7 in this step, and pipe jacking construction is carried out to connect the two adjacent new pipeline 1 construction areas.

[0048] In order to facilitate the construction, the pipe jacking construction is carried out in the same direction in the construction areas of different new pipelines 1. In step six, the position and direction of the pipe jacking device and the machine head 10 are exchanged in the working well 6.

[0049] After the construction of the new pipeline 1 is completed, the foundation pit 3 is backfilled, and the support rods 2-3 are removed before the piles are pulled out. For old buildings with fragile structures, after the construction is completed, the piles may not be pulled out, and the support system 2 may be left on the ground, but the crown beam 2-2 and exposed steel sections on the top of the support system 2 must be broken or removed to prevent the building foundation 4 from being affected during the pile pulling construction process.

[0050] The present invention plans the construction area based on BIM, avoids the existing pipeline 11 that crosses the construction area, adopts the support system 2 to support the construction area of ​​the new pipeline 1, and performs semi-excavation jacking construction in the closed area surrounded by the support system 2. Under the protection of the support system 2, the water and soil stability around the construction area is guaranteed, the impact of the pipeline construction in the construction area of ​​the new pipeline 1 on the surrounding building foundations 4 is reduced, and the deformation of the surrounding building foundations 4 can be effectively prevented. At the same time, the support system 2 forms a closed water-stop curtain to ensure the construction safety in the construction area of ​​the new pipeline 1.

[0051] The present invention adopts semi-excavation pipe jacking construction, which reduces the amount of excavation and reduces the imbalance of the forces inside and outside the support system 2, thereby improving the stability of the support system 2. At the same time, since the top of the pipeline is exposed during the semi-excavation pipe jacking process, it is convenient to intuitively control the pipe jacking construction process.

Claims

1. A semi-excavation pipe jacking method for underground pipelines under complex environmental conditions based on BIM, characterized in that: The following steps are involved: Step 1: Use modeling software to build a BIM 3D model of the construction area. The BIM 3D model includes buildings and existing pipelines around the construction area. Step 2: Determine the location and size of the new pipeline construction area in the BIM three-dimensional model according to the locations of the buildings and existing pipelines around the planned new pipeline. The new pipeline construction area extends along the length of the planned new pipeline, and two adjacent new pipeline construction areas are separated by the existing pipeline that crosses the planned new pipeline. Step 3: construct the support system in the new pipeline construction area determined in step 2. The support system is constructed along the edge of the new pipeline construction area and encloses a closed area; Step 4: excavate earth in the closed area formed by the support system to form a foundation pit. The depth of the foundation pit is the top depth of the planned new pipeline, and the top of the pipeline is exposed during the subsequent jacking construction; Step 5: In the closed area formed by the support system, construct a working well at one end and a receiving well at the other end, install the jacking equipment and machine head in the working well, and then carry out the jacking construction in the closed area formed by the support system.

2. The semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 1 is characterized in that: The support system is an SMW method pile, a cap beam is cast on the top of the SMW method pile, and support rods are set between the cap beams on both sides of the new pipeline to be constructed.

3. The semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 1 is characterized in that: In step five, the pipe segment is hoisted into the working well by the lifting equipment, and the pipe segment is pushed forward by the pipe jacking equipment. After the pipe segment is pushed into place, the pipe jacking equipment retreats and installs the subsequent pipe segment. The jacking and subsequent pipe segment installation are repeated until the working well is connected with the receiving well.

4. The semi-excavation pipe jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 1 is characterized in that: It also includes step six: connecting each section of the new pipeline, specifically including: using the working well / receiving well at the end of one of the two adjacent new pipeline construction areas as the working well in this step, and using the working well / receiving well at the end of the other new pipeline construction area as the receiving well in this step, performing pipe jacking construction, and connecting the two adjacent new pipeline construction areas.

5. The semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 4 is characterized in that: In different new pipeline construction areas, pipe jacking construction is carried out in the same direction. In step six, the position and direction of the pipe jacking device and the machine head are exchanged in the working pit.

6. The semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 1 is characterized in that: In step 2, the distance between the edge of the new pipeline construction area and the foundation edge of the surrounding buildings is greater than or equal to 2 meters.

7. The semi-excavation jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 1 is characterized in that: Dewatering wells are set up in the closed area formed by the support system, and dewatering is carried out before foundation pit excavation. Monitoring wells are set up around the closed area formed by the support system, and the groundwater level is tested at any time during construction.

8. The semi-excavation pipe jacking method for underground pipelines under complex environmental conditions based on BIM according to claim 2 is characterized in that: After the construction of the new pipeline is completed, the foundation pit will be backfilled, and the piles will be pulled out after the support poles are removed.

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