A method for optimizing the transformation of the original prefabricated pipe pile tower crane foundation on a deep soft foundation

Abstract

The invention discloses a transformation and optimization method for an original prefabricated pipe pile tower crane foundation on a deep soft foundation. The method determines the pipe pile positions that can enter the rock in the original prefabricated pipe piles of the floor on the tower crane foundation construction area according to the geological conditions of the tower crane foundation construction area and the stress load of the tower crane foundation, and then drives the pipe piles at the corresponding positions into the rock layer by using the method of leading holes into the rock, and the driving depths of the original prefabricated pipe piles of the floor at other positions remain unchanged. After the pipe pile driving is completed and a rest period is performed according to the interval of the stratum soil quality, the rock-entering pipe piles are subjected to high strain detection, and the pipe pile core pouring construction is performed after the qualified ones are qualified, and finally the tower crane foundation is arranged on the pipe piles, and the tower crane is installed on the tower crane foundation. The existing pipe piles in the tower crane construction area are transformed to make them suitable for the deep soft geology, so as to avoid adding new piles, reduce the manufacturing and construction costs of the new piles, and also reduce the interference to the environment and the consumption of resources, thereby meeting the requirements of green construction and sustainable development.

Description

Technical Field

[0001] The invention relates to the technical field of tower crane installation in construction engineering, and in particular to a method for transforming and optimizing an original prefabricated pipe pile tower crane foundation on a deep soft foundation. Background Art

[0002] There are many caves and silt geological conditions in South China. With the continuous development of the logistics industry, there are more and more smart storage parks. Due to the functional requirements of storage and stacking, the general design will set up floor pipe piles in the storage area to ensure the load. In order to ensure construction efficiency and construction period, tower crane transportation is generally considered during construction. For large warehouses, tower cranes are often erected in the warehouse considering factors such as transportation capacity.

[0003] At present, the foundation of tower cranes on deep soft soil generally adopts cast-in-place pile foundation or pipe pile foundation. The cast-in-place pile tower crane foundation has the following problems: first, the cost is relatively high; second, no matter the construction order of the tower crane cast-in-place piles and the originally designed floor pipe piles, there will be a soil squeezing effect, which will affect the safety of the tower crane or the floor pile position. The pipe pile foundation has the following problems: first, the position of the newly added pipe piles conflicts with the originally designed floor pipe piles; second, the soil squeezing effect of the construction order of the two piles needs to be considered; third, the tower crane has a large deadweight, and the pipe pile foundation is located under the karst cave and deep soft soil. The safety of the bearing layer at the pile end is unknown, and it is difficult to meet the bearing requirements by relying solely on the pile side resistance, which poses a safety hazard.

[0004] Therefore, the current use of cast-in-place pile foundations or pipe pile foundations will have safety issues. Therefore, how to design or modify the existing tower crane foundation so that it can maintain sufficient bearing capacity and anti-deformation ability on deep soft soil is an issue that urgently needs to be solved. Summary of the invention

[0005] In view of this, the present invention provides a method for transforming and optimizing an original prefabricated pipe pile tower crane foundation on a deep soft foundation, so as to solve the safety problem of the tower crane foundation in caves and silt soft foundation.

[0006] A method for optimizing the transformation of an existing prefabricated pipe pile tower crane foundation on a deep soft foundation specifically comprises the following steps:

[0007] S1, conduct geological survey on the tower crane foundation construction area;

[0008] S2, determine the position of the rock-entering pipe pile according to the geological conditions of the tower crane foundation construction area and the load of the tower crane foundation;

[0009] S3, according to the determined position of the rock-entering pipe pile, the original prefabricated pipe piles at the corresponding position on the tower crane foundation construction area are driven into the rock layer by using the down-the-hole drilling method, and the driving depth of the original prefabricated pipe piles at other positions remains unchanged;

[0010] S4, high strain testing of rock-penetrating piles to assess the actual bearing capacity of their foundations;

[0011] S5, perform core pouring construction on all pipe piles in the tower crane foundation construction area, wherein the length of the first core pouring in the rock-entering pipe pile is not less than 2m, and the length of the second core pouring in the original prefabricated pipe piles at other locations is the standard core pouring length;

[0012] S6, according to the actual bearing capacity of each pile foundation, in accordance with the requirements of the 23G409 drawing of "Prestressed Concrete Pipe Piles by Prestressing Method", a tower crane foundation is set on the piles;

[0013] S7, backfilling a compacted soil layer around the tower crane foundation, and setting a floor slab cushion layer on the surface of the compacted soil layer, and setting a drainage ditch at the connection between the floor slab cushion layer and the tower crane foundation;

[0014] S8, install the tower crane on the tower crane foundation and conduct commissioning and safety inspection.

[0015] Preferably, the upper surface of the tower crane foundation is a slope that slopes downward from the middle to the surrounding edges, and the slope is 3%.

[0016] Preferably, the method further includes step S9, regularly performing maintenance and monitoring on the tower crane to ensure the safety of the long-term operation of the tower crane.

[0017] Preferably, within 2 to 3 weeks after the completion of tower crane commissioning and safety inspection, monitoring should be carried out at least 5 times a week and the monitoring data should be recorded. After the monitoring data is stable, the detection frequency should be no less than 2 times a week.

[0018] Preferably, the existing prefabricated pipe piles on the tower crane foundation construction area are distributed in a matrix, and the rock-penetrating pipe piles are located at the four corners.

[0019] Preferably, in step S4, the standard core filling length is 1.5 m.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention determines the positions of the pipe piles that can enter the rock in the original prefabricated pipe piles of the floor in the construction area of ​​the tower crane foundation according to the geological conditions of the construction area of ​​the tower crane foundation and the stress load of the tower crane foundation, and then drives the pipe piles at the corresponding positions into the rock layer by using the method of leading holes into the rock, and the driving depths of the original prefabricated pipe piles of the floor at other positions remain unchanged. After all the pipe piles are driven and the dormant period of the stratum soil ends, the high-strain test is performed on the rock-entering pipe piles, and the pipe pile core pouring construction is performed after the high-strain test is qualified. Finally, the tower crane foundation is set on the pipe piles, and the tower crane is installed on the tower crane foundation. The existing pipe piles in the tower crane construction area are modified to make them suitable for deep soft soil, thereby avoiding adding new piles, reducing the manufacturing and construction costs of new piles, and also reducing the interference to the environment and the consumption of resources, which meets the requirements of green construction and sustainable development.

[0022] 2. The present invention improves the adaptability of the tower crane foundation to complex geological conditions by conducting advance drilling and ensuring rock penetration, reduces the uncertainty and safety risks caused by deep soft base geological problems during the construction process, and can better adapt to complex geological conditions.

[0023] 3. The present invention increases the length of the core filling in the rock-penetrating pipe pile to ensure the requirements of the rock-penetrating pile foundation, thereby improving the overall bearing capacity and anti-deformation capacity of the tower crane foundation and improving the safety of the tower crane in use.

[0024] 4. The present invention utilizes high strain detection technology to detect each pipe pile to evaluate the actual bearing capacity of its respective pile foundation, which greatly shortens the construction detection time, shortens the construction period, and improves the construction efficiency.

[0025] 5. The present invention adopts a prefabricated pipe pile rock construction method and standardized detection technology, which reduces the quality impact caused by geological conditions and construction errors, helps to establish a standardized construction process, and reduces the impact of human factors on construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is the structural plan of the tower crane foundation.

[0028] Figure 2 It is a longitudinal section of the tower crane foundation.

[0029] The meanings of the numbers in the figure are:

[0030] 1. Rock-entered pipe piles, 2. Existing prefabricated pipe piles at other locations, 3. Tower crane foundation, 4. Drainage ditch, 5. Floor slab cushion, 6. Rammed soil layer, 7. First grouting core, 8. Second grouting core. DETAILED DESCRIPTION

[0031] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is described below by the specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are only exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the description of well-known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present invention.

[0032] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0033] In order to better understand the technical solution of the present invention, the present invention is described in detail below with reference to the accompanying drawings.

[0034] The present invention provides a method for optimizing the transformation of an existing prefabricated pipe pile tower crane foundation on a deep soft foundation, which specifically comprises the following steps:

[0035] S1. Conduct geological survey on the tower crane foundation construction area and determine whether the tower crane foundation construction area is a deep soft foundation based on the geological survey results.

[0036] S2, determine the position of the rock-entering pipe pile according to the geological conditions of the tower crane foundation construction area and the load of the tower crane foundation.

[0037] Specifically, the specific location of the tower crane foundation is determined based on the plan of the prefabricated pipe piles in the tower crane foundation construction area, and the bearing capacity of the tower crane foundation and the tower crane is analyzed based on the geological survey results and the advance drilling results, combined with the tower crane manual, so as to comprehensively judge the location of the rock-entering pipe piles.

[0038] In this embodiment, the original prefabricated pipe piles on the tower crane foundation construction area are distributed in a matrix, and the rock-entering pipe piles are located at the four corners. Since the corner piles have a large shear resistance and there is no exploration record of one pile and one hole at the bottom of the pipe piles, the original prefabricated pipe piles at the four corners of the tower crane foundation are pre-drilled to clarify the geological conditions at the four corners, especially the specific location of the rock layer.

[0039] S3, according to the determined position of the rock-entering pipe pile, the lead hole depth is determined according to the advance drilling report, and the original prefabricated pipe piles at the corresponding position on the tower crane foundation construction area are first driven to the lead hole depth by the down-the-hole drilling method. After the soil rest period of the stratum is over, the rock-entering pipe piles are subjected to high strain testing to verify the integrity and bearing capacity of the pile body. After passing the test, the pipe pile core pouring construction is carried out;

[0040] The piling depth of the original prefabricated floor pipe piles 2 at other locations remains unchanged.

[0041] That is, the original prefabricated pipe piles at the four corners are bored to ensure that the depth of the bored holes reaches the rock layer. After the boring is completed, all the pipe piles at the location of the tower crane foundation are constructed at the same time ( Figure 1 The 9 pipe piles shown in the figure are driven at the same time), among which the original prefabricated floor pipe piles in 4 corners extend into the rock layer to become rock-entering pipe piles 1, and the original prefabricated floor pipe piles 2 in the remaining 5 other positions are driven into the corresponding depth under the ground according to the original design drawings.

[0042] S4, after the soil rest period, high strain tests are performed on the rock-entry pipe piles 1 at the four corners to evaluate the actual bearing capacity of their respective pile foundations.

[0043] S5, core pouring construction is performed on all pipe piles in the tower crane foundation construction area, wherein the length of the first core pouring 7 in the rock-entering pipe pile 1 is not less than 2m, and the length of the second core pouring 8 in the original prefabricated pipe pile 2 at other locations is the standard core pouring length. The standard core pouring length required by the "Prestressed Concrete Pipe Piles by Pretensioning Method" 23G409 atlas is 1.5m.

[0044] Preferably, the length of the first grouting core 7 in the rock-entered pipe pile 1 is 2 m, and the length of the second grouting core 8 in the original prefabricated floor pipe pile 2 at other positions is 1.5 m.

[0045] S6. According to the actual bearing capacity of each pipe pile foundation and in accordance with the requirements of the Atlas 23G409 of Prestressed Concrete Piles, a tower crane foundation 3 is set on the pipe piles to ensure that the connection between the tower crane foundation 3 and the pile foundation is stable.

[0046] S7, backfill the compacted soil layer 6 around the tower crane foundation 3, and set a floor slab cushion layer 5 on the surface of the compacted soil layer 6, and set a drainage ditch 4 at the connection between the floor slab cushion layer 5 and the tower crane foundation 3.

[0047] The upper surface of the tower crane foundation 3 is a slope that slopes downward from the middle to the edges around it, and the slope is 3%.

[0048] S8, installing the tower crane on the tower crane foundation 3. After the tower crane is installed, necessary debugging and safety inspection are carried out according to the tower crane manual to ensure the stability and safety of the tower crane.

[0049] The method further includes step S9, regularly performing maintenance and monitoring on the tower crane to ensure the safety of long-term operation of the tower crane. Specifically, within 2 to 3 weeks after the tower crane is debugged and the safety inspection is completed, monitoring is performed at least 5 times a week and the monitoring data is recorded. After the monitoring data is stable, the detection frequency is not less than 2 times a week.

[0050] It should be clear that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Claims

1. A method for optimizing the transformation of an existing prefabricated pipe pile tower crane foundation on a deep soft foundation, characterized in that: The specific steps include: S1, conduct geological survey on the tower crane foundation construction area; S2, determine the position of the rock-entering pipe pile according to the geological conditions of the tower crane foundation construction area and the load of the tower crane foundation; The original prefabricated pipe piles on the tower crane foundation construction area are distributed in a matrix, and the rock-entering pipe piles are located at four corners; S3, according to the determined position of the rock-entering pipe pile, the original prefabricated floor pipe pile at the corresponding position on the tower crane foundation construction area is driven into the rock layer by using the down-the-hole drilling method, and the driving depth of the original prefabricated floor pipe pile (2) at other positions remains unchanged; S4, high strain testing of rock-penetrating piles to assess the actual bearing capacity of their foundations; S5, performing core pouring construction on all pipe piles in the tower crane foundation construction area, wherein the core pouring length in the rock-entering pipe pile (1) is not less than 2 m, and the core pouring length in the original floor prefabricated pipe pile (2) at other locations is the standard core pouring length; The standard core length is 1.5m; S6, according to the actual bearing capacity of each pile foundation, in accordance with the requirements of the drawing set 23G409 of Prestressed Concrete Piles, a tower crane foundation (3) is set on the piles; S7, backfilling a compacted soil layer (6) around the tower crane foundation (3), and providing a floor slab cushion layer (5) on the surface of the compacted soil layer (6), and providing a drainage ditch (4) at the connection between the floor slab cushion layer (5) and the tower crane foundation (3); S8, install the tower crane on the tower crane foundation (3) and perform commissioning and safety inspection.

2. The method for optimizing the transformation of the original prefabricated pipe pile tower crane foundation on the deep soft foundation according to claim 1 is characterized in that: The upper surface of the tower crane foundation (3) is a slope that slopes downward from the middle to the surrounding edges, and the slope is 3%.

3. The method for optimizing the transformation of the original prefabricated pipe pile tower crane foundation on the deep soft foundation according to claim 1 is characterized in that: The method further comprises step S9, regularly performing maintenance and monitoring on the tower crane to ensure the safety of the long-term operation of the tower crane.

4. The method for optimizing the transformation of the original prefabricated pipe pile tower crane foundation on the deep soft foundation according to claim 3 is characterized in that: Within 2 to 3 weeks after completing the tower crane commissioning and safety inspection, conduct monitoring at least 5 times a week and record the monitoring data. After the monitoring data stabilizes, the weekly inspection frequency shall not be less than 2 times.

Images