阅读说明：本技术 应用于珊瑚礁地质的原位搅拌钢管桩施工系统及方法 (In-situ stirring steel pipe pile construction system and method applied to coral reef geology ) 是由 张永涛 潘桂林 吴启和 刘建波 张磊 仇正中 万猛 于 2019-09-29 设计创作，主要内容包括：本发明公开了应用于珊瑚礁地质的原位搅拌钢管桩施工系统及方法,系统包括：钢管桩,其包括一体成型的上部标准段和下部扩径段,所述钢管桩侧面具有多个开孔；回旋动力装置,其连接有钻杆,所述钻杆为空心杆；注浆管路；扩底钻头；方法包括：准备；钻进,当扩底钻头钻进至钢管桩底部的扩径段时,将扩底钻头扩径并继续钻进；通过钻杆将固化浆注入孔底,并通过钻杆旋转带动扩径钻头的旋转搅拌作用与珊瑚礁砂混合均匀,固化浆-珊瑚礁砂混合体通过钢管桩上的开孔充满标准段内外。本发明结合了原位搅拌桩和钢管桩的施工方法,将钻孔、沉桩、灌浆三道工序整合为一道工序,具有承载力高、施工效率高、工程造价低的优点。(The invention discloses an in-situ stirring steel pipe pile construction system and method applied to coral reef geology, wherein the system comprises the following steps: the steel pipe pile comprises an upper standard section and a lower expanding section which are integrally formed, and the side surface of the steel pipe pile is provided with a plurality of openings; the rotary power device is connected with a drill rod, and the drill rod is a hollow rod; grouting pipelines; a bottom expanding drill bit; the method comprises the following steps: preparing; drilling, namely expanding the diameter of the bottom-expanding drill bit and continuously drilling when the bottom-expanding drill bit drills to the diameter-expanding section at the bottom of the steel pipe pile; the solidified slurry is injected into the bottom of the hole through the drill rod, the solidified slurry and the coral reef sand are uniformly mixed under the rotating stirring action of the drill rod which rotates to drive the expanding drill bit, and the solidified slurry-coral reef sand mixture is filled inside and outside the standard section through the opening on the steel pipe pile. The invention combines the construction method of the in-situ mixing pile and the steel pipe pile, integrates three procedures of drilling, pile sinking and grouting into one procedure, and has the advantages of high bearing capacity, high construction efficiency and low construction cost.)

1. Be applied to normal position stirring steel-pipe pile construction system of coral reef geology, its characterized in that includes:

the steel pipe pile is fixed at a design position through a pile machine and comprises an upper standard section and a lower expanding section which are integrally formed, and the side surface of the steel pipe pile is provided with a plurality of holes;

the rotary power device is arranged at the upper part of the steel pipe pile, is connected with a drill rod and is positioned inside the steel pipe pile, and the drill rod is a hollow rod;

one end of the grouting pipeline is communicated with the drill rod, and the other end of the grouting pipeline is connected with an external grouting device;

and the bottom expanding drill bit is connected to the bottom of the drill rod and does not interfere the bottom of the drill rod to be communicated with the interior of the steel pipe pile.

2. The in-situ stirring steel pipe pile construction system applied to coral reef geology as claimed in claim 1, wherein the diameter of the diameter-expanded section is greater than 0.1 times of the diameter of the standard section.

3. The in-situ stirring steel pipe pile construction system applied to coral reef geology as claimed in claim 1, wherein said under-reamed drill comprises:

the hydraulic telescopic rod is fixedly connected to the drill rod, and the bottom end of a reducing rod of the hydraulic telescopic rod is connected with the drill bit body;

the fixing piece is fixedly sleeved on the hydraulic telescopic rod;

the pair of diameter expanding rods are symmetrically positioned at two sides of the hydraulic telescopic rod, and the upper ends of the diameter expanding rods are hinged to the fixing piece;

and the upper ends of the connecting rods are hinged on the diameter expanding rod, and the lower ends of the connecting rods are hinged on the drill bit body.

4. The in-situ stirring steel pipe pile construction system applied to coral reef geology as claimed in claim 1, wherein the side surface of the bottom of the drill rod is provided with a plurality of small holes communicated with the inside of the steel pipe pile.

5. The in-situ stirring steel pipe pile construction system applied to coral reef geology as claimed in claim 3, wherein the bottom-expanding diameter of the bottom-expanding drill bit is slightly smaller than the diameter of the diameter-expanded section and slightly larger than the diameter of the standard section.

6. The method for constructing an in-situ stirring steel pipe pile applied to coral reef geology as claimed in claim 1, which is characterized by comprising the following steps:

step 1: measuring and positioning, namely installing and fixing the steel pipe pile at a designed position through a pile machine, enabling the steel pipe pile to enter a part of a soil body under the action of self weight, preparing solidified slurry and connecting a grouting pipeline;

step 2: installing a rotary power device on the upper part of the steel pipe pile, putting a bottom-expanding drill bit into the steel pipe pile through a drill rod, and drilling to form a hole;

and step 3: when the bottom expanding drill bit drills into the expanding section at the bottom of the steel pipe pile, expanding the bottom expanding drill bit and continuing drilling, wherein the diameter of a formed hole is slightly larger than the diameter of the standard section of the steel pipe pile and slightly smaller than the diameter of the expanding section; in the drilling and pore-forming process, the solidified slurry is injected into the bottom of the hole all the time through the drill rod, and the drill rod rotates to drive the expanding drill bit to rotate and stir so as to be uniformly mixed with the coral reef sand;

and 4, step 4: after the steel pipe pile is drilled to a certain depth, the bottom of the steel pipe pile is basically hollow, so that the steel pipe pile can continuously enter a soil body under the action of self weight, and the solidified slurry-coral reef sand mixture is filled inside and outside the standard section through the opening on the steel pipe pile;

and 5: drilling to the designed bottom elevation, continuously injecting curing slurry and rotating the expanding drill bit, and stirring for a period of time until the end of the steel pipe pile is pressed to be compact; and finally, reducing the diameter of the bottom expanding drill bit and pulling out the bottom expanding drill bit, and completing construction of in-situ stirring the steel pipe pile after the solidification slurry-coral reef sand mixture is condensed and maintained.

Technical Field

The invention relates to the technical field of pile foundation construction. More particularly, the invention relates to an in-situ stirring steel pipe pile construction system and method applied to coral reef geology.

Background

The driving-in type steel pipe pile is low in cost, quick in construction process and universal in offshore engineering. Although the technology related to driving the steel pipe pile is mature, in the coral reef stratum, the driving process can damage breakable particles and a soil structure, so that the side friction resistance of the steel pipe pile is very low, and the problem that the pile slipping or the vertical bearing capacity cannot meet the design requirement can be caused. Offshore projects in the sea areas of south China sea, the red sea, West of the Mediterranean sea, Western Australia, Western India, etc. all suffer from such problems. At present, the problem is generally solved by drilling and grouting the steel pipe pile abroad, namely, drilling is firstly carried out, then holes are cleaned, then the steel pipe pile is inserted, and finally grouting is carried out. Although the method solves the problem of low side friction resistance of the steel pipe pile, the method has the advantages of multiple working procedures, long construction period and high cost, and cracks are easy to generate after solidification of the solidified slurry. The problem can also be solved to a certain extent by grouting after driving the steel pipe pile, but grouting coverage rate is difficult to ensure, pile side frictional resistance is unstable, and pressure grouting can cause certain damage to a soil body structure, but reduces the bearing capacity of the soil body structure. Meanwhile, the surface layer of the coral reef is often covered with rocks or high consolidated soil, and the steel pipe pile is easy to curl in the driving process, so that the whole steel pipe pile is scrapped.

Disclosure of Invention

The invention aims to provide an in-situ stirring steel pipe pile construction system and method applied to coral reef geology, which combine the construction methods of an in-situ stirring pile and a steel pipe pile, integrate three procedures of drilling, pile sinking and grouting into one procedure and have the advantages of high bearing capacity, high construction efficiency and low construction cost.

To achieve these objects and other advantages in accordance with the present invention, there is provided an in-situ stirring steel pipe pile construction system applied to coral reef geology, including: the steel pipe pile is fixed at a design position through a pile machine and comprises an upper standard section and a lower expanding section which are integrally formed, and the side surface of the steel pipe pile is provided with a plurality of holes; the rotary power device is arranged at the upper part of the steel pipe pile, is connected with a drill rod and is positioned inside the steel pipe pile, and the drill rod is a hollow rod; one end of the grouting pipeline is communicated with the drill rod, and the other end of the grouting pipeline is connected with an external grouting device; and the bottom expanding drill bit is connected to the bottom of the drill rod and does not interfere the bottom of the drill rod to be communicated with the interior of the steel pipe pile.

Preferably, the diameter of the expanded diameter section is greater than 0.1 times the diameter of the standard section.

Preferably, the under-reamer comprises: the hydraulic telescopic rod is fixedly connected to the drill rod, and the bottom end of a reducing rod of the hydraulic telescopic rod is connected with the drill bit body; the fixing piece is fixedly sleeved on the hydraulic telescopic rod; the pair of diameter expanding rods are symmetrically positioned at two sides of the hydraulic telescopic rod, and the upper ends of the diameter expanding rods are hinged to the fixing piece; and the upper ends of the connecting rods are hinged on the diameter expanding rod, and the lower ends of the connecting rods are hinged on the drill bit body.

Preferably, the side surface of the bottom of the drill rod is provided with a plurality of small holes communicated with the interior of the steel pipe pile.

Preferably, the diameter of the bottom expanding drill bit is slightly smaller than the diameter of the diameter expanding section and slightly larger than the diameter of the standard section.

The invention also provides an in-situ stirring steel pipe pile construction method applied to coral reef geology, which comprises the following steps:

step 1: measuring and positioning, namely installing and fixing the steel pipe pile at a designed position through a pile machine, enabling the steel pipe pile to enter a part of a soil body under the action of self weight, preparing solidified slurry and connecting a grouting pipeline;

step 2: installing a rotary power device on the upper part of the steel pipe pile, putting a bottom-expanding drill bit into the steel pipe pile through a drill rod, and drilling to form a hole;

and step 3: when the bottom expanding drill bit drills into the expanding section at the bottom of the steel pipe pile, expanding the bottom expanding drill bit and continuing drilling, wherein the diameter of a formed hole is slightly larger than the diameter of the standard section of the steel pipe pile and slightly smaller than the diameter of the expanding section; in the drilling and pore-forming process, the solidified slurry is injected into the bottom of the hole all the time through the drill rod, and the drill rod rotates to drive the expanding drill bit to rotate and stir so as to be uniformly mixed with the coral reef sand;

and 4, step 4: after the steel pipe pile is drilled to a certain depth, the bottom of the steel pipe pile is basically hollow, so that the steel pipe pile can continuously enter a soil body under the action of self weight, and the solidified slurry-coral reef sand mixture is filled inside and outside the standard section through the opening on the steel pipe pile;

and 5: drilling to the designed bottom elevation, continuously injecting curing slurry and rotating the expanding drill bit, and stirring for a period of time until the end of the steel pipe pile is pressed to be compact; and finally, reducing the diameter of the bottom expanding drill bit and pulling out the bottom expanding drill bit, and completing construction of in-situ stirring the steel pipe pile after the solidification slurry-coral reef sand mixture is condensed and maintained.

The invention at least comprises the following beneficial effects:

the construction method combines the in-situ mixing pile and the steel pipe pile, integrates three procedures of drilling, pile sinking and grouting into one procedure, solves the problems of low side friction of the driven steel pipe pile and high cost of drilling and grouting the steel pipe pile under the coral reef geological condition, and has the advantages of high bearing capacity, high construction efficiency and low construction cost.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

FIG. 1 is a schematic diagram of a construction method of an in-situ stirring steel pipe pile according to the present invention.

Fig. 2 is a partially enlarged view of the bottom of the in-situ stirring steel pipe pile during construction.

Fig. 3 is a schematic elevation view of the steel pipe pile of the present invention.

FIG. 4 is a schematic view of the under-reamed bit of the present invention before expanding;

FIG. 5 is a schematic view of the bottom-reaming bit of the present invention after expanding its diameter.

Description of reference numerals:

1. the pile driver comprises a pile driver body, 2 parts of a steel pipe pile, 3 parts of a rotary power device, 4 parts of a drill rod, 5 parts of a bottom expanding drill bit, 6 parts of a grouting pipeline, 2-1 parts of a standard section, 2-2 parts of an expanding section, 2-3 parts of a hole, 5-1 parts of a reducing rod, 5-2 parts of a hydraulic telescopic rod, 5-3 parts of a fixing part, 5-4 parts of an expanding rod, 5-5 parts of a connecting rod, 5-6 parts of a drill bit body.

Detailed Description

The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.

It is to be noted that the experimental methods described in the following embodiments are all conventional methods unless otherwise specified, and the reagents and materials, if not otherwise specified, are commercially available; in the description of the present invention, the terms "lateral", "longitudinal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

As shown in fig. 1 to 3, the present invention provides an in-situ stirring steel pipe pile construction system applied to coral reef geology, including: the steel pipe pile 2 is fixed at a design position through a pile machine 1, the steel pipe pile 2 comprises an upper standard section 2-1 and a lower expanding section 2-2 which are integrally formed, and the side surface of the steel pipe pile 2 is provided with a plurality of openings 2-3; the rotary power device 3 is arranged at the upper part of the steel pipe pile 2, the rotary power device 3 is connected with a drill rod 4 and is positioned inside the steel pipe pile 2, and the drill rod 4 is a hollow rod; one end of the grouting pipeline 6 is communicated with the drill rod 4, and the other end of the grouting pipeline 6 is connected with an external grouting device; and the bottom expanding drill bit 5 is connected to the bottom of the drill rod 4 and does not interfere with the bottom of the drill rod 4 to be communicated with the inside of the steel pipe pile 2.

The invention also provides an in-situ stirring steel pipe pile construction method applied to coral reef geology, which comprises the following steps:

step 1: measuring and positioning, namely installing the steel pipe pile 2 at a designed position through the pile machine 1 and fixing, enabling the steel pipe pile 2 to enter a part of a soil body under the action of self weight, preparing solidified slurry and connecting a grouting pipeline 6;

step 2: installing a rotary power device 3 at the upper part of the steel pipe pile 2, putting a bottom-expanding drill bit 5 into the steel pipe pile 2 through a drill rod 4, and drilling to form a hole;

and step 3: when the bottom-expanding drill bit 5 drills into the diameter expanding section 2-2 at the bottom of the steel pipe pile 2, expanding the bottom-expanding drill bit 5 and continuing drilling, wherein the diameter of a formed hole is slightly larger than the pile diameter of the standard section 2-1 of the steel pipe pile 2 and slightly smaller than the pile diameter of the diameter expanding section 2-2; in the drilling and pore-forming process, the solidified slurry is injected into the bottom of the hole through the drill rod 4 all the time, and is uniformly mixed with the coral reef sand through the rotary stirring action of the drill rod 4 which rotates to drive the expanding drill bit;

and 4, step 4: after the steel pipe pile is drilled to a certain depth, the bottom of the steel pipe pile 2 is basically hollow, so that the steel pipe pile can continuously enter a soil body under the action of self weight, and the solidified slurry-coral reef sand mixture is filled inside and outside the standard section 2-1 through the opening 2-3 on the steel pipe pile 2;

and 5: drilling to the designed bottom elevation, continuously injecting curing slurry and rotating the expanding drill bit, and stirring for a period of time until the end part of the steel pipe pile 2 is pressed to be compact; and finally, reducing the diameter of the bottom expanding drill bit 5 and pulling out the bottom expanding drill bit, and completing the construction of the in-situ stirring steel pipe pile 2 after the solidification slurry-coral reef sand mixture is condensed and maintained.

In the technical scheme, the steel pipe pile 2 is composed of a standard section 2-1 and an expanding section 2-2, on one hand, the expanding section 2-2 is arranged to enable a certain gap to be formed between the standard section 2-1 of the steel pipe pile 2 and the side face of coral reef geology, and a mixture formed by mixing solidified slurry and coral reef sand can permeate into the gap on the side face through an opening 2-3 formed in the steel pipe pile 2, so that the binding force between the steel pipe pile 2 and the coral reef is ensured, and the side frictional resistance of the steel pipe pile is improved; on the other hand, when the bottom expanding drill bit 5 expands the bottom, the hole diameter of the bottom expanding drill bit is slightly smaller than the diameter of the diameter expanding section 2-2, and the outer side of the bottom of the diameter expanding section 2-2 can be stably positioned on the peripheral un-drilled soil body, as shown in fig. 2, so that the stability of the steel pipe pile 2 is ensured, the central line of the steel pipe pile 2 can be always basically overlapped with the central line of the final hole, and the smooth and stable hole forming is ensured. The rotary power device 3 is an existing conventional drilling machine, which is connected with the drill rod 4 and can drive the drill rod 4 to move downwards and rotate. Grouting pipeline 6 is pressed the solidification thick liquid into drilling rod 4 through the mud jacking device to be located inside and outside steel-pipe pile 2 through drilling rod 4, drilling rod 4 bottom side is provided with the inside aperture of a plurality of intercommunication steel-pipe pile 2, and the solidification thick liquid that uses can form certain intensity after mixing with coral reef sand through the design of mix proportion, for about 5 MPa. The bottom expanding drill bit 5 performs expanding drilling when drilling to the expanding section 2-2, and can be taken out in a contracting mode after drilling is completed, and the bottom expanding drill bit 5 is simple in structure, convenient to operate and capable of being taken out directly. The diameter of the diameter expansion section 2-2 is 0.1 times larger than that of the standard section 2-1, namely, taking the steel pipe pile 2 with the diameter of 2m as an example, the diameter of the diameter expansion section 2-2 is 20cm larger than that of the standard section 2-1 of the steel pipe pile 2. The construction of the steel pipe pile 2 requires 3 to 5 hours, and the curing of the curing slurry requires 24 hours, so the construction of the invention can be completely implemented and the better technical effect can be achieved.

Under the geological condition of the coral reef, a bottom-expanding drill bit 5 is placed at the bottom of the steel pipe pile 2 through a drill rod 4, hole-expanding drilling is carried out, and the diameter of a formed hole is slightly larger than the diameter of 2-1 of the standard section of the steel pipe pile and slightly smaller than the diameter of 2-2 of the expanded section. In the drilling process, the solidified slurry is injected into the hole through the drill rod 4, the solidified slurry and the coral reef sand are uniformly mixed under the rotating stirring action of the bottom-expanding drill bit 5, and the solidified slurry flows to the outside of the steel pipe pile 2 through the openings 2-3 at the bottom and the side surface of the steel pipe pile 2. After the construction is finished, the inside and the outside of the steel pipe pile 2 are wrapped by the mixture of the curing slurry and the coral reef sand, and the side frictional resistance of the steel pipe pile 2 can be improved after the condensation.

As shown in fig. 4 and 5, in a preferred embodiment of the in-situ stirring steel pipe pile construction system applied to the coral reef geology of the present application, the under-reamed drill 5 includes: the hydraulic telescopic rod 5-2 is fixedly connected to the drill rod 4, and the bottom end of the reducing rod 5-1 of the hydraulic telescopic rod 5-2 is connected with the drill bit body 5-6; the fixing piece 5-3 is fixedly sleeved on the hydraulic telescopic rod 5-2; the pair of diameter expanding rods 5-4 are symmetrically arranged on two sides of the hydraulic telescopic rod 5-2, and the upper ends of the diameter expanding rods 5-4 are hinged to the fixing pieces 5-3; and the pair of connecting rods 5-5 are also symmetrically positioned at two sides of the hydraulic telescopic rod 5-2, the upper ends of the connecting rods 5-5 are hinged on the diameter expanding rod 5-4, and the lower ends of the connecting rods 5-5 are hinged on the drill bit body 5-6.

In the technical scheme, the bottom expanding of the bottom expanding drill bit 5 is realized by the expansion and contraction of a hydraulic telescopic rod 5-2, in particular to the up-and-down expansion and contraction of a reducing rod 5-1 in the hydraulic telescopic rod 5-2, and the expansion and contraction are controlled by a controller connected with the construction ground through a line. When the diameter-reducing rod 5-1 is stretched up and down, the pair of connecting rods 5-5 are driven to stretch inward and outward, so that the pair of diameter-expanding rods 5-4 are driven to stretch inward and outward, and the diameter expanding and reducing of the bottom expanding drill bit 5 are realized.

The concrete construction effect of the invention is as follows:

side friction resistance problem: the coral reef geology is driven through the general direct pile of steel-pipe pile, and the side frictional resistance is about 0 ~ 20kPa, and after adopting this technology, the side frictional resistance is at 100 ~ 200 KPa.

In the aspect of vertical bearing capacity: taking a steel pipe pile with the diameter of 1m and the height of 20m as an example, the steel pipe pile is driven into a coral reef stratum for 20m calculation, and is driven by a traditional piling boat, the ultimate bearing capacity of the steel pipe pile is about 2400kN, and the bearing capacity of the steel pipe pile is 7500kN after the steel pipe pile is formed by adopting the process.

Construction efficiency: the piling time of the traditional steel pipe pile is 40min, while the process is used for 5h, and the cast-in-place pile is drilled for 3 days.

While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.