阅读说明：本技术 一种超深振冲桩施工方法 (Construction method of ultra-deep vibroflotation pile ) 是由 卢伟 李晓力 姚军平 高强 梁兴龙 段宝利 马科 于 2020-11-19 设计创作，主要内容包括：本发明提供一种超深振冲桩施工方法,通过下护筒,旋挖引孔的方式穿过回填层和硬层,避免振冲设备直接造孔时回填层塌孔,再通过导杆对接的方式,快速插接增设上导杆,延长整个导杆的长度,使底部导杆组件悬挂振冲器继续造孔至目标深度。本发明通过导杆对接的方式,快速插接增设上导杆,延长整个导杆的长度,使底部导杆组件悬挂振冲器造孔轻松达到目标深度,施工质量、效率、经济性、便利性均达到设计要求。(The invention provides a construction method of an ultra-deep vibroflotation pile, which is characterized in that a backfill layer and a hard layer are penetrated through a lower protective cylinder in a rotary drilling and hole guiding mode, so that hole collapse of the backfill layer is avoided when vibroflotation equipment directly conducts hole forming, an upper guide rod is rapidly inserted and added in a guide rod butt joint mode, the length of the whole guide rod is prolonged, and a bottom guide rod assembly is suspended with a vibroflotation device to continue hole forming to a target depth. According to the invention, the upper guide rod is rapidly inserted and added in a guide rod butt joint mode, the length of the whole guide rod is prolonged, the hole forming of the bottom guide rod component suspension vibroflot is easy to reach the target depth, and the construction quality, efficiency, economy and convenience all reach the design requirements.)

1. A construction method of an ultra-deep vibroflotation pile is characterized by comprising the following steps: at the construction depth of 0-40 m, hanging a vibroflot through a lower protective cylinder and a bottom guide rod assembly, and forming holes in a rotary drilling and guiding manner;

at the construction depth of 40 m to 100 m, an upper guide rod is rapidly inserted and connected in a butt joint mode through the guide rod, the length of the whole guide rod is prolonged, and the bottom guide rod assembly is suspended on the vibroflot to continuously form holes to the target depth.

2. The construction method of the ultra-deep vibroflotation pile according to claim 1, wherein the pile casing is arranged at a softer backfill layer above a hard layer, the wall thickness of the pile casing is 8mm-20mm, the inner diameter is selected after the outer diameter of vibroflotation equipment and the particle size of aggregate are considered comprehensively, and generally the outer diameter of the vibroflotation equipment is increased by 400mm-600 mm.

3. The construction method of the ultra-deep vibroflotation pile according to claim 2, wherein the depth of the rotary drilling guide hole is greater than 0.5m to 1.5m of the length of the pile casing, and the depth is basically above the stratum hard layer.

4. The ultra-deep vibroflotation pile construction method according to claim 3, wherein the bottom guide rod assembly comprises a middle junction box, a plurality of sections of lower guide rods with different lengths, a bottom junction box, a shock absorber and a vibroflotation device;

the lower guide rod is a hollow steel pipe, and two ends of the lower guide rod are respectively welded with a connecting flange; according to the depth of the hole, a plurality of sections of lower guide rods are connected with each other through bolts and connecting flanges at two ends of the lower guide rods;

the middle junction box, the lower guide rod, the bottom junction box, the shock absorber and the vibroflot are in quick butt joint with each other through bolts and connecting flanges or through hexagonal connectors and pin shafts which are matched with each other;

the total length of the assembled bottom guide rod assembly is 35-45 meters.

5. The ultra-deep vibroflotation pile construction method according to claim 4, wherein the upper guide rod is a hollow steel pipe, the top end of the upper guide rod is provided with an inner hexagonal connecting flange, and the tail end of the upper guide rod is provided with an outer hexagonal quick plug which is matched with the front end and has the length of 500mm-600 mm;

when the depth of the hole is more than 40 m, the hanging head, the middle junction box and the cable inside the middle junction box are quickly disassembled, and the upper guide rod is additionally arranged between the hanging head and the middle junction box;

connecting the front end of the upper guide rod with the hanging head, quickly inserting the tail end of the upper guide rod into the front end of the middle junction box, and locking by using a pin shaft;

along with the continuous increase of the depth of the hole, quickly disassembling a pin shaft between the tail end of the hanging head and the front end of the upper guide rod, separating the tail end of the hanging head and the front end of the upper guide rod, quickly inserting a section of upper guide rod and a middle junction box at the front end of the upper guide rod, and quickly fixing the tail end of the newly inserted upper guide rod and the front end of the original upper guide rod through the pin shaft; therefore, the upper guide rod is continuously inserted at the front end of the upper guide rod, and the length of the upper guide rod is prolonged;

the total length of the upper guide rod is 30-40 m.

Technical Field

The invention relates to a construction method of an ultra-deep vibroflotation pile. The invention belongs to the technical field of piling construction.

Background

In recent years, with the rapid development of cities, the scale of infrastructure engineering construction is getting larger, the regional extent and the stratum are complex, certain difficulty is brought to vibroflotation composite foundation treatment, and the vibroflotation composite foundation treatment method is mainly embodied in the aspects of composite foundation treatment depth, quality control and the like.

In recent two or three years, the conventional vibroflotation construction method in China combines certain informatization control means in the aspect of pile forming quality control, can realize accurate construction, and can effectively control the quality. However, in the aspect of the construction depth of the vibroflotation pile, certain difficulty is brought to the existing construction method. According to the conventional vibroflotation pile construction method, the construction depth is less than 35 meters (namely, within 0-35 meters), and when the construction depth exceeds 40 meters, the construction difficulty is increased by exponential order! The main reason is that the domestic market has no mature construction process and matched construction equipment which can be used, and the large equipment manufacturing enterprises are coordinated to do a large amount of work and complement each other, so that the defects still exist.

At present, a great number of attempts are made in the same industry in the construction method and equipment of the ultra-deep vibroflotation pile, for example, construction is performed by suspending a vibroflotation device through a telescopic guide rod, but a plurality of problems exist in the construction process, such as: 1. the construction equipment has a complex structure. The hole forming depth of the ultra-deep vibroflotation pile construction site is about 90-100 meters, and the total length of the telescopic guide rod after underground (in-hole) expansion reaches about 100 meters, so that the whole construction equipment, particularly the telescopic guide rod part, is large in size and complex in structure. 2. The anti-liquefaction effect is not ideal. The telescopic guide rod is structurally thick and located at the upper part of the hole, the outer diameter of the telescopic guide rod is almost equal to or slightly larger than the outer diameter of the vibroflot, the blanking space of aggregate is small, the aggregate reaching the head of the vibroflot is reduced, and the construction efficiency is low. 3. The vibro-replacement pore is not ideal. The diameter of the outermost guide rod of the telescopic guide rod is large, the diameter of the innermost guide rod is small, the telescopic dead weight of the last section of guide rod is small, and particularly, the vibration punching hole is not facilitated when a hard layer is encountered. 4. The control cable that controls the vibroflot is easily pulled apart. At present, a control cable for controlling the action of the vibroflotation system is connected with a vibroflotation device hung at the lower end of a guide rod along the guide rod, and due to the stretching of a telescopic guide rod, the control cable is frequently and constantly pulled, so that the control cable is extremely easy to pull and break, the construction progress is influenced, and the workload is increased.

Disclosure of Invention

In view of the above, the present invention aims to provide a new construction method for ultra-deep vibroflotation piles, which conforms to the vibroflotation foundation-compacting construction principle, and has the advantages of high pile body quality, short construction period and high construction efficiency.

In order to achieve the purpose, the invention adopts the following technical scheme: a construction method of an ultra-deep vibroflotation pile is characterized by comprising the following steps: at the construction depth of 0-40 m, hanging a vibroflot through a lower protective cylinder and a bottom guide rod assembly, and forming holes in a rotary drilling and guiding manner;

at the construction depth of 40 m to 100 m, an upper guide rod is rapidly inserted and connected in a butt joint mode through the guide rod, the length of the whole guide rod is prolonged, and the bottom guide rod assembly is suspended on the vibroflot to continuously form holes to the target depth.

In the preferred embodiment of the invention, the pile casing is arranged at a softer backfill layer above a hard layer, the wall thickness of the pile casing is 8mm-20mm, the inner diameter is selected after the outer diameter of vibroflotation equipment and the particle size of aggregate are comprehensively considered, and the outer diameter of the vibroflotation equipment is preferably increased by 400mm-600 mm.

In a preferred embodiment of the invention, the depth of the rotary drilling guide hole is greater than 0.5m-1.5m of the length of the casing, and the depth is basically above the stratum hard layer.

In a preferred embodiment of the present invention, the bottom guide bar assembly comprises a middle junction box, a plurality of sections of lower guide bars with different lengths, a bottom junction box, a shock absorber and a vibroflot;

the lower guide rod is a hollow steel pipe, and two ends of the lower guide rod are respectively welded with a connecting flange; according to the depth of the hole, a plurality of sections of lower guide rods are connected with each other through bolts and connecting flanges at two ends of the lower guide rods;

the middle junction box, the lower guide rod, the bottom junction box, the shock absorber and the vibroflot are in quick butt joint with each other through bolts and connecting flanges or through hexagonal connectors and pin shafts which are matched with each other;

the total length of the assembled bottom guide rod assembly is 35-45 meters.

In the preferred embodiment of the invention, the upper guide rod is a hollow steel pipe, the top end of the upper guide rod is provided with an inner hexagonal connecting flange, and the tail end of the upper guide rod is provided with an outer hexagonal quick plug which is matched with the front end and has the length of 500mm-600 mm;

when the depth of the hole is more than 40 m, the hanging head, the middle junction box and the cable inside the middle junction box are quickly disassembled, and the upper guide rod is additionally arranged between the hanging head and the middle junction box;

connecting the front end of the upper guide rod with the hanging head, quickly inserting the tail end of the upper guide rod into the front end of the middle junction box, and locking by using a pin shaft;

along with the continuous increase of the depth of the hole, quickly disassembling a pin shaft between the tail end of the hanging head and the front end of the upper guide rod, separating the tail end of the hanging head and the front end of the upper guide rod, quickly inserting a section of upper guide rod and a middle junction box at the front end of the upper guide rod, and quickly fixing the tail end of the newly inserted upper guide rod and the front end of the original upper guide rod through the pin shaft; therefore, the upper guide rod is continuously inserted at the front end of the upper guide rod, and the length of the upper guide rod is prolonged;

the total length of the upper guide rod is 30-40 m

The invention has the beneficial effects that:

1. according to the invention, through a mode of quickly inserting the guide rod, the ultra-deep vibroflotation pile construction can be realized, the height and the tonnage of hoisting equipment can be effectively reduced, and the construction risk is reduced.

2. The invention can ensure the vibroflotation hole forming and the construction quality encryption by rapidly inserting the guide rod and prolonging the length of the guide rod, and can effectively avoid the influence on the construction progress caused by the fracture of the control cable due to continuous pulling when the vibroflotation system controls the vibroflotation device to act.

3. Can practically and effectively meet all requirements of ultra-deep construction.

4. The upper guide rod with the extendable length is connected in a butt joint mode of the six-square-head quick plug-in, so that the connection is quick, accurate and safe, the whole ultra-deep hole forming, filling and compacting processes are sequentially connected, the pile manufacturing process is carried out in a flow process, and the whole construction efficiency is maximized.

Drawings

FIG. 1 is a flow chart of the construction method of the ultra-deep vibroflotation pile of the invention;

FIG. 2 is a schematic view of the construction equipment for ultra-deep vibroflotation piles according to the present invention;

FIG. 3 is a schematic view of a lower guide bar construction constituting the bottom guide bar assembly of the present invention;

FIG. 4 is a schematic view of an intermediate junction box forming the bottom guide bar assembly of the present invention;

FIG. 5 is a schematic view of a bottom terminal block forming the bottom guide assembly of the present invention;

FIG. 6 is a schematic structural view of a lifting head I constituting the ultra-deep vibroflotation pile construction equipment of the present invention;

FIG. 7 is a schematic view of an upper guide rod structure constituting the ultra-deep vibroflotation pile construction apparatus of the present invention;

fig. 8 is a schematic structural view of a hanging head ii constituting the ultra-deep vibroflotation pile construction equipment of the present invention.

Detailed Description

The structure and features of the present invention will be described in detail below with reference to the accompanying drawings and examples. It should be noted that various modifications can be made to the embodiments disclosed herein, and therefore, the embodiments disclosed in the specification should not be construed as limiting the present invention, but merely as exemplifications of embodiments thereof, which are intended to make the features of the present invention obvious.

In order to realize the construction of the ultra-deep vibroflotation pile, the whole construction process accords with the vibroflotation foundation-compacting construction principle, the vibroflotation foundation-compacting construction quality is ensured, and the pile body quality is ensured, the method of the invention is as follows: firstly, at the construction depth of 0-40 m, suspending a vibroflot through a lower protective cylinder and a bottom guide rod assembly, and forming holes in a rotary drilling and guiding manner;

at the construction depth of 40 m to 100 m, an upper guide rod is rapidly inserted and connected in a butt joint mode through the guide rod, the length of the whole guide rod is prolonged, and the bottom guide rod assembly is suspended on the vibroflot to continuously form holes to the target depth.

The ultra-deep vibroflotation pile construction method of the invention is detailed below with reference to fig. 1, as shown in the figure:

s1, before the hole is formed in the vibroflotation equipment, the protective cylinder is arranged at the backfill layer above the hard layer by a vibration hammer.

Because the hole depth is usually 40-100 m when the ultra-deep vibroflotation pile is constructed, in order to ensure that the engineering is smoothly carried out and the blanking is smoother, before the vibroflotation equipment starts to form holes, the invention uses the vibration hammer to lower the pile casing, thereby avoiding the hole collapse of the backfill layer when the vibroflotation equipment directly forms the holes.

The wall thickness of the protective cylinder is 8mm-20mm, the inner diameter is determined by the outer diameter of vibroflotation equipment and the particle size of aggregate, and the outer diameter of the protective cylinder is generally 400mm-600mm larger than that of the vibroflotation equipment. The length of the casing depends on the geological conditions on site, and usually the casing is located at a backfill layer above a hard layer or a soft geological layer which is easy to collapse.

And S2, forming holes in a mode of digging lead holes in a rotating mode at 0-40 m, and penetrating the backfill layer and the hard layer.

The hole forming method of the vibroflotation equipment has a plurality of modes, for example, the vibroflotation of a telescopic guide rod, the vibroflotation equipment adopts a rotary drilling hole leading mode to form the hole, and the hole forming mode has the advantages that: the construction difficulty is low, and the security is high. The depth of the rotary drilling guide hole is larger than 0.5m-1.5m of the length of the pile casing, and the depth is basically positioned above a stratum hard layer.

As shown in figure 2, the equipment for ultra-deep vibroflotation pile construction comprises a lifting device 1, a lifting hook 2, a lifting steel wire rope 3, a lifting head I4 and a bottom guide rod assembly.

The bottom guide rod component comprises a middle junction box 5-1, a plurality of sections of lower guide rods 5 with different lengths, a bottom junction box 5-2, a shock absorber 6 and a vibroflot 7. As shown in fig. 3, the lower guide rod 5 is a hollow steel pipe, and two ends of the hollow steel pipe are respectively welded with a connecting flange 5-3. According to the depth of the hole, a plurality of sections of the lower guide rod 5 can be connected with each other through bolts and connecting flanges at two ends of the lower guide rod. Fig. 4 is a schematic structural view of the intermediate junction box, and as shown in fig. 4, the front end 5-1-1 of the intermediate junction box 5-1 is an inner hexagonal connecting flange, and the rear end 5-1-2 is a connecting flange. The rear end 5-1-2 of the middle junction box 5-1 is connected with the top end of the lower guide rod 5 through a bolt and a connecting flange. FIG. 5 is a schematic structural view of the bottom junction box, and as shown in FIG. 5, the front end 5-2-1 and the rear end 5-2-2 of the bottom junction box 5-2 are both connecting flanges. The front end of the bottom junction box 5-2 is connected with the tail end of the lower guide rod 5 through a bolt and a connecting flange; the rear end of the bottom junction box 5-2 is connected with the top end of a shock absorber 6 through a bolt and a connecting flange, and the tail end of the shock absorber 6 is connected with a vibroflot 7 through a bolt and a connecting flange. The total length of the assembled bottom guide bar assembly may be about 35-45 meters.

Fig. 6 is a schematic structural diagram of the hanging head I. As shown in figure 6, a lifting pulley is welded at the top end 4-1 of a lifting head I4, an outer hexagonal quick plug with the length of 500mm-600mm is welded at the tail end 4-2 of the lifting head I4, and a water inlet 4-3 and a cable inlet 4-4 are formed in the middle of the lifting head I4. The tail end 4-2 of the hanging head I4 is inserted into the front end 5-1-1 of the middle junction box 5-1 in the bottom guide rod component and locked through a pin shaft.

As shown in figure 2, a lifting device 1 can complete the hole forming of 0-40 m by hanging a bottom guide rod component through a lifting hook 2, a lifting steel wire rope 3 and a lifting head I4. When the vibroflotation system operates the vibroflotation device 7 to work, the control cable is connected with the control end of the vibroflotation device 7 through the cable inlet 4-4 of the hanging head I4, the middle junction box 5-1, the hollow lower guide rod 5, the bottom junction box 5-2 and the shock absorber 6. When the vibroflotation device works, high-pressure water needs to be sprayed to the working surface of the vibroflotation device, and the high-pressure water flows through the water inlet 4-1 of the hanging head I4, the middle junction box 5-1, the hollow lower guide rod 5, the bottom junction box 5-2 and the shock absorber 6 and is sprayed out from the bottom of the vibroflotation device 7.

S3, quickly inserting a guide rod, and prolonging the length of the guide rod to enable the depth of the vibro-replacement hole to reach the target depth;

as shown in FIG. 2, the ultra-deep vibroflotation pile construction equipment further comprises a hanging head II 8 and a plurality of sections of upper guide rods 9 capable of realizing rapid insertion.

In order to realize ultra-deep hole forming and overcome the defects of the traditional telescopic guide rod hole forming equipment, the invention continuously inserts the guide rod 9 along with the increase of the hole forming depth, and prolongs the length of the guide rod, so that the hole forming depth of the vibroflotation device 7 reaches the target depth of 90-100 m.

As shown in FIG. 7, each upper guide rod 9 is a hollow steel pipe, the top end 9-1 is an inner hexagonal connecting flange, and the tail end 9-2 is an outer hexagonal quick plug which is matched with the front end and has the length of 500mm-600 mm.

Fig. 8 is a schematic structural view of a suspension head ii constituting the present invention. As shown in figure 8, the front end 8-1 of the hanging head II 8 is a hoisting pulley, the rear end 8-2 thereof is a connecting flange connected with the upper guide rod, and the middle part of the hanging head II 8 is provided with a water inlet 8-3 and a cable inlet 8-4.

The rear end 8-2 of the hanging head II 8 is connected with the front end 9-1 of the upper guide rod 9 through a bolt and a connecting flange, and the rear end of the upper guide rod 9 is inserted into the front end 5-1-1 of the middle junction box 5-1.

When the depth of the hole is more than 40 m, the hanging head I4 is quickly detached along with the increase of the depth of the hole, the hanging head II 8 connected with the upper guide rod 9 is replaced, the tail end of the upper guide rod 9 is quickly inserted into the front end 5-1-1 of the middle junction box 5-1, and the middle junction box is locked by a pin shaft.

As shown in fig. 2, the lifting device 1 is used for hanging a bottom guide rod assembly for hole forming through a lifting hook 2, a lifting steel wire rope 3, a lifting head ii 8 and an upper guide rod 9. The control cable is connected with the control end of the vibroflotation device 7 through a cable inlet 8-4 of the hanging head II 8, an upper guide rod 9, a middle junction box 5-1, a hollow lower guide rod 5, a bottom junction box 5-2 and a shock absorber 6; high-pressure water is sprayed out from the bottom of the vibroflot 7 through a water inlet 8-3 of the hanging head II 8, an upper guide rod 9, a middle junction box 5-1, a hollow lower guide rod 5, a bottom junction box 5-2 and a shock absorber 6.

Along with the continuous increase of the depth of the hole, quickly disassembling a pin shaft between the tail end 8-2 of the hanging head II 8 and the front end 9-1 of the upper guide rod, separating the two, quickly inserting a new section of upper guide rod at the front end 9-1 of the upper guide rod, and quickly fixing the tail end 9-2 of the newly inserted upper guide rod 9 and the front end 9-1 of the original upper guide rod through the pin shaft; therefore, the upper guide rod is continuously inserted at the front end of the upper guide rod, the length of the upper guide rod is prolonged, and the purpose is that the hole-forming depth of the vibroflot reaches the target depth.

S4, repeatedly cleaning the hole while forming the hole, expanding the pile diameter and preventing the hole periphery from collapsing to generate a hole holding phenomenon;

s5, filling;

adding a proper amount of graded aggregate to ensure the quality;

s6, compacting;

lifting the vibroflotation device to a certain height, and performing reverse insertion until a dense current is reached, so that the vibroflotation device can not be lifted again; when the first-stage upper guide rod is completely exposed out of the ground, the first-stage upper guide rod can be disassembled; and after all the upper guide rods are removed, removing the hanging head II, replacing the hanging head I, inserting the tail end of the hanging head I and the front end of the middle junction box in the bottom guide rod assembly, locking the hanging head I through a pin shaft, and then performing vibroflotation and densification.

S7, repeating the steps S4-S6 until the vibroflotation equipment reaches the designed elevation or is exposed out of the ground, and forming a vertical reinforcement consisting of broken stones;

and S8, pulling the pile casing, and completing pile manufacturing.

In the process of deep hole forming and lower casing protection, if the arc stone and other conditions occur, the method can be used for processing by using a method of impact drilling or breaking by a down-the-hole hammer or directly digging by rotary drilling.

According to the invention, the upper guide rod is rapidly inserted and added in a guide rod butt joint mode, the length of the whole guide rod is prolonged, the hole forming of the bottom guide rod component suspension vibroflot is easy to reach the target depth, and the construction quality, efficiency, economy and convenience all reach the design requirements.

Finally, it should be noted that: the above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.