Stress-controllable spiral steel pipe-cement soil combined bearing structure

Abstract

The utility model discloses a stress-controllable spiral steel pipe-cement soil combined bearing structure. The stress-controllable spiral steel pipe-cement soil combined bearing structure comprises a steel pipe, a steel ring cylinder, a fastener, a spiral blade and a limiting assembly, the steel ring cylinder slidably sleeves the outer wall of the steel pipe; the fastener is mounted on the steel ring cylinder; the spiral blade is mounted on the outer wall of the steel ring cylinder; the limiting assembly is installed on the steel pipe. The spiral blades are connected with the steel pipe in a sliding mode, loads are transmitted to the spiral blades on the lower portion in the load bearing process, stress is redistributed at the same time, the loads are evenly distributed, the problem of stress concentration at the connecting position of the spiral blades on the upper portion and the steel pipe is solved, the bearing performance is improved, and energy consumption is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of civil engineering, in particular to a stress-controllable spiral steel pipe-cement soil combined bearing structure. Background Art

[0002] Under the national requirements for building a resource-saving and environmentally friendly society, low-carbon and sustainable development in the engineering field is imperative, and the adoption of energy-saving and more economical engineering measures and methods is an inevitable choice for development. In the basic construction of various projects, pile foundations can often provide considerable bearing capacity, but this is accompanied by high costs and huge energy and material consumption. In some engineering constructions that only require a small bearing capacity, such as the construction of photovoltaic power stations on coastal tidal flats, a large amount of resources are often wasted in order to meet the minimum requirements of the specifications. At this time, if you choose to use rigid cement-soil composite piles, it will greatly reduce the cost and energy consumption.

[0003] Reinforced cement-soil composite pile is a new type of composite pile in which the reinforced core pile is vertically implanted into the cement-soil mixing pile after the construction of the cement-soil mixing pile is completed, so that the outer periphery is wrapped by cement soil. It has the larger pile side friction resistance of the cement-soil mixing pile and the higher strength and stiffness of the core pile.

[0004] At present, the rigid core piles in the rigid cement-soil composite piles are in the form of pipe piles, steel pipes, spiral steel pipes, etc. Among them, for the rigid cement-soil composite piles with spiral steel pipes as the inner core, the load they bear is mostly concentrated on the upper spiral blades. There is stress concentration at the welding position between the steel pipe and the spiral blades, while the load shared by the lower spiral blades is too small.

[0005] Therefore, the utility model proposes a stress-controllable spiral steel pipe-cement soil combined bearing structure. Utility Model Content

[0006] The utility model aims to provide a stress-controllable spiral steel pipe-cement soil combined bearing structure, aiming to solve or improve at least one of the above-mentioned technical problems.

[0007] To achieve the above purpose, the utility model provides the following solution: The utility model provides a stress-controllable spiral steel pipe-cement soil combined bearing structure, including:

[0008] Steel pipe;

[0009] A steel ring cylinder, wherein the steel ring cylinder is sleeved on the outer wall of the steel pipe and the steel ring cylinder is slidably connected to the outer wall of the steel pipe;

[0010] A fastener, the fastener is installed on the steel ring tube; the fastener is used to adjust the gap between the inner wall of the steel ring tube and the outer wall of the steel pipe;

[0011] A spiral blade, wherein the spiral blade is mounted on the outer wall of the steel ring cylinder;

[0012] A limit assembly is installed on the steel pipe, and the limit assembly and the steel ring tube are in limit cooperation.

[0013] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the steel ring tube includes two symmetrically arranged semicircular steel sleeves, the two semicircular steel sleeves are detachably connected by the fasteners, and the spiral blades are fixedly connected to the outer walls of the two semicircular steel sleeves.

[0014] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, flange ears are respectively fixedly connected to the two semicircular steel sleeves, and the flange ears of the two semicircular steel sleeves are detachably connected through the fasteners.

[0015] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the fasteners include bolts, and the flange ears of the two semicircular steel sleeves are threadedly connected by the bolts.

[0016] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the limiting assembly includes two blocking protrusions fixedly connected to the outer wall of the steel pipe, and the steel ring tube is arranged between the two blocking protrusions and cooperates with the two blocking protrusions to limit the position.

[0017] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the steel pipe between the two blocking protrusions is set as a steel pipe sliding section; the steel ring tube is slidably connected to the outer wall of the steel pipe sliding section.

[0018] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the outer wall of the steel pipe sliding section is a rough surface.

[0019] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the outer wall of the steel pipe sliding section is a smooth surface.

[0020] According to the stress-controllable spiral steel pipe-cement soil combined bearing structure provided by the utility model, the inner wall of the steel ring tube is a rough surface or a smooth surface.

[0021] The utility model also provides an application method of a stress-controllable spiral steel pipe-cement soil combined bearing structure, comprising the following steps:

[0022] Step 1: Detect underground obstacles in the construction area of ​​the combined load-bearing structure, clear the obstacles, level the site, and compact it in layers;

[0023] Step 2: Excavate to the designed elevation, measure and position according to the requirements, and make permanent and temporary signs;

[0024] Step 3: Position the three-axis mixing pile hole, put the pile driver in place, prepare and inject cement slurry as required, control the sinking and lifting speed of the mixing pile driver as required, and form a cement-soil mixing pile;

[0025] Step 4: Install the steel ring tube on the steel pipe to form a spiral steel pipe inner core pile, ensure the pile position, verticality and elevation of the pile body, and rotate it into the outer core cement soil mixing pile.

[0026] The utility model discloses the following technical effects:

[0027] The utility model transforms the stable and unchanging welding connection between the existing spiral blades and the steel pipe into a friction sliding connection, adjusts the gap between the inner wall of the steel ring tube and the outer wall of the steel pipe by fasteners, and then adjusts the sliding friction between the steel ring tube wall and the contact surface of the steel pipe. In the load-bearing process, the load is transmitted to the lower spiral blade more through the relative sliding between the steel ring tube and the steel pipe, and the stress is redistributed at the same time to achieve the purpose of uniform distribution of the load along the entire length of the pile body, which greatly alleviates the problem of stress concentration at the connection between the upper spiral blade and the steel pipe in the prior art, better conforms to the load transfer theory of rigid cement-soil composite piles, can better provide compressive bearing capacity when the steel ring tube moves upward relative to the steel pipe, and can also better provide pull-out bearing capacity when it moves downward relatively, which has better bearing performance, saves materials and reduces energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0029] Figure 1 This is an axonometric diagram of the stress-controllable spiral steel pipe-cement soil combined bearing structure of the utility model;

[0030] Figure 2 It is a schematic diagram of the installation of the spiral blade and the steel ring cylinder in the utility model;

[0031] Figure 3 This is a schematic diagram of the installation of the steel pipe and the limit assembly in the utility model;

[0032] Among them, 1. spiral blades; 2. steel ring cylinder; 3. steel pipe; 4. steel pipe sliding section; 5. barrier protrusion; 6. flange ear plate; 7. bolts. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0034] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0035] Reference Figure 1-3 The utility model provides a stress controllable spiral steel pipe-cement soil combined bearing structure, including:

[0036] Steel pipe 3; in this embodiment, the steel pipe 3 adopts a commonly used steel pipe in construction;

[0037] The steel ring tube 2 is sleeved on the outer wall of the steel pipe 3, and the steel ring tube 2 is slidably connected to the outer wall of the steel pipe 3;

[0038] A fastener is installed on the steel ring tube 2; the fastener is used to adjust the gap between the inner wall of the steel ring tube 2 and the outer wall of the steel pipe 3;

[0039] The spiral blade 1 is fixedly connected to the outer wall of the steel ring cylinder 2;

[0040] The limit assembly is installed on the steel pipe 3, and the limit assembly cooperates with the steel ring tube 2;

[0041] In this way, the utility model transforms the stable and unchanging welding connection between the existing spiral blade 1 and the steel pipe 3 into a friction sliding connection, adjusts the gap between the inner wall of the steel ring tube 2 and the outer wall of the steel pipe 3 by fasteners, and then adjusts the sliding friction between the inner wall of the steel ring tube 2 and the contact surface of the steel pipe 3, and in the load-bearing process, the load is transmitted more to the lower spiral blade 1 through the relative sliding between the steel ring tube 2 and the steel pipe 3, and at the same time, the stress is redistributed to achieve the purpose of uniform distribution of the load along the entire length of the pile body of the rigid cement-soil composite pile, which greatly alleviates the problem of stress concentration at the connection between the upper spiral blade 1 and the steel pipe 3 in the prior art, and better conforms to the load transfer theory of the rigid cement-soil composite pile, which can better provide compressive bearing capacity when the steel ring tube 2 moves upward relative to the steel pipe 3, and can also better provide pull-out bearing capacity when it moves relatively downward, which has better bearing performance, saves materials, and reduces energy consumption.

[0042] According to a further optimized solution, the steel ring cylinder 2 includes two symmetrically arranged semicircular steel sleeves, the two semicircular steel sleeves are detachably connected by fasteners, and the spiral blades 1 are fixedly connected to the outer walls of the two semicircular steel sleeves;

[0043] By arranging several steel ring tubes 2 along the length direction of the steel pipe 3 and arranging several spiral blades 1 along the length direction of the steel pipe 3, the shear stress per unit area is dispersed and reduced, thereby meeting the greater shear strength requirement of the interface between the outer core cement soil pile and the inner core steel pipe pile.

[0044] According to a further optimized solution, flange ear plates 6 are respectively fixedly connected to the two semicircular steel sleeves, and the flange ear plates 6 of the two semicircular steel sleeves are detachably connected via fasteners.

[0045] A further optimized solution is that the fasteners include bolts 7, and the flange ear plates 6 of the two semicircular steel sleeves are threadedly connected by bolts 7; the tightness between the contact surfaces of the steel ring tube 2 and the steel pipe 3 is controlled by controlling the torque of the bolts 7 and the nuts, thereby adjusting the sliding friction between the two.

[0046] Further optimized solution, the limit assembly includes two barrier protrusions 5 fixedly connected to the outer wall of the steel pipe 3, the steel ring tube 2 is arranged between the two barrier protrusions 5, and is limited with the two barrier protrusions 5; in this embodiment, the minimum distance between the two barrier protrusions 5 is greater than the length of the steel ring tube 2, and the maximum displacement of the steel ring tube 2 is limited by the barrier protrusions 5; at the same time, the length of the steel ring tube 2 and the distance between the two barrier protrusions 5 are extended, so as to improve the load capacity of the single-channel spiral blade 1;

[0047] By placing the steel ring tube 2 in the middle of the two barrier protrusions 5, the pile body of the rigid cement-soil composite pile can provide better compressive bearing capacity and better tensile bearing capacity.

[0048] To further optimize the solution, the steel pipe 3 between the two blocking protrusions 5 is set as a steel pipe sliding section 4; the steel ring tube 2 is slidably connected to the outer wall of the steel pipe sliding section 4.

[0049] According to a further optimization scheme, the outer wall of the steel pipe sliding section 4 is a smooth surface.

[0050] A further optimization scheme is that the outer wall of the steel pipe sliding section 4 is a rough surface; by roughening the outer wall of the steel pipe sliding section 4, the initial value of the sliding friction resistance between the contact surface of the steel pipe 3 and the steel ring tube 2 can be increased, thereby meeting the greater shear strength requirement between the two.

[0051] Further optimization scheme, the inner wall of the steel ring tube 2 is a rough surface or a smooth surface; by roughening the inner wall of the steel ring tube 2, the initial value of the sliding friction resistance between the contact surface of the steel pipe 3 and the steel ring tube 2 can be increased, thereby meeting the greater shear strength requirement between the two;

[0052] Through the accumulation of multiple experiments, the relationship curve between the torque between the bolt 7 and the nut and the sliding friction resistance between the contact surfaces of the steel ring tube 2 and the steel pipe 3 under different degrees of roughening treatment can be fitted, and then the empirical formula between the torque and sliding friction resistance, the degree of roughening treatment and the friction coefficient can be established through regression analysis, so that it can be better applied to engineering.

[0053] The utility model also provides an application method of a stress-controllable spiral steel pipe-cement soil combined bearing structure, comprising the following steps:

[0054] Step 1: Detect underground obstacles in the construction area of ​​the combined load-bearing structure, clear the obstacles, level the site, and compact it in layers;

[0055] Step 2: Excavate to the designed elevation, measure and position according to the actual construction requirements, and make permanent and temporary signs;

[0056] Step 3: Position the three-axis mixing pile hole, put the pile driver in place, prepare and inject cement slurry as required, control the sinking and lifting speed of the mixing pile driver as required, and form a cement-soil mixing pile;

[0057] Step 4: Install the steel ring tube 2 on the steel pipe 3 to form a spiral steel pipe inner core pile, ensure the pile position, pile body verticality and elevation, and rotate it to implant it into the outer core cement soil mixing pile.

[0058] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0059] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not intended to limit the implementation methods of the utility model. For ordinary technical users in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is not necessary and impossible to list all the implementation methods here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. Stress controllable spiral steel pipe-cement soil combined bearing structure, characterized in that: include: Steel pipe (3); A steel ring cylinder (2), wherein the steel ring cylinder (2) is sleeved on the outer wall of the steel pipe (3), and the steel ring cylinder (2) is slidably connected to the outer wall of the steel pipe (3); A fastener, the fastener being mounted on the steel ring cylinder (2); the fastener being used to adjust the gap between the inner wall of the steel ring cylinder (2) and the outer wall of the steel pipe (3); A spiral blade (1), wherein the spiral blade (1) is mounted on the outer wall of the steel ring cylinder (2); A limit assembly is installed on the steel pipe (3), and the limit assembly and the steel ring tube (2) are in limit cooperation.

2. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 1 is characterized in that: The steel ring cylinder (2) comprises two symmetrically arranged semicircular steel sleeves, the two semicircular steel sleeves are detachably connected via the fasteners, and the spiral blades (1) are fixedly connected to the outer walls of the two semicircular steel sleeves.

3. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 2 is characterized in that: The two semicircular steel sleeves are respectively fixedly connected with flange ear plates (6), and the flange ear plates (6) of the two semicircular steel sleeves are detachably connected via the fasteners.

4. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 3 is characterized in that: The fastener comprises a bolt (7), and the flange ear plates (6) of the two semicircular steel sleeves are threadedly connected via the bolt (7).

5. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 1 is characterized in that: The limiting assembly comprises two blocking protrusions (5) fixedly connected to the outer wall of the steel pipe (3); the steel ring tube (2) is arranged between the two blocking protrusions (5) and is limitedly matched with the two blocking protrusions (5).

6. The stress controllable spiral steel pipe-cement soil combined bearing structure according to claim 5 is characterized in that: The steel pipe (3) between the two blocking protrusions (5) is a steel pipe sliding section (4); the steel ring tube (2) is slidably connected to the outer wall of the steel pipe sliding section (4).

7. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 6 is characterized in that: The outer wall of the steel pipe sliding section (4) is a rough surface.

8. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 6 is characterized by: The outer wall of the steel pipe sliding section (4) is a smooth surface.

9. The stress-controlled spiral steel pipe-cement soil composite bearing structure according to claim 1 is characterized by: The inner wall of the steel ring cylinder (2) is a rough surface or a smooth surface.

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