Solid waste bulk pile composite foundation structure and construction method thereof

Abstract

The present application relates to a kind of solid waste bulk pile composite foundation structure, and composite foundation structure is suitable for soft soil foundation;Solid waste bulk pile composite foundation structure includes: several bulk piles, in soft soil foundation It is distributed in rectangle or plum blossom shape, the surface of all bulk piles is wrapped with geogrid, and soft soil is filled between adjacent bulk piles;Hidden pile, hidden pile is arranged in bulk pile, the surface of hidden pile is wrapped with geogrid, and soft soil is filled between hidden pile and bulk pile;Connecting band, connect all bulk piles to form connecting grid layer, the surface of connecting band is wrapped with geogrid;The composition material of bulk pile and connecting band includes solid waste material and water-absorbing expansion resin.The present application also relates to a kind of construction method of solid waste bulk pile composite foundation structure.The present application is cooperated by bulk pile and geogrid, so that all bulk piles and soft soil between piles form composite foundation, realize the deep reinforcement of soft soil foundation, belong to soft soil foundation treatment technical field.

Description

Technical Field

[0001] This invention relates to the field of soft soil foundation treatment technology, specifically to a solid waste bulk pile composite foundation structure and its construction method. Background Technology

[0002] The foundation soil in alluvial plains and deltas where major rivers flow into the sea is often composed of deep soft soil, some exceeding 50 meters in depth. Construction of roads and buildings on such foundations necessitates soft soil treatment. However, current foundation treatment methods for these deep soft soil foundations present numerous challenges. For instance, reinforcing deep soft soil foundations using precast pipe piles or various end-bearing piles involves long piles, high costs, and a relatively small contribution of the soft soil's own strength to the foundation's bearing capacity, resulting in lower resistance to lateral deformation after treatment. Furthermore, pipe pile construction significantly impacts surrounding buildings, and the pipe piles themselves experience substantial settlement deformation. In river deltas with low elevations and high water levels, this has a significant impact on the structural design of superstructures. Moreover, to achieve flushness with the surrounding ground, extensive backfilling is often required.

[0003] Therefore, existing soft soil foundation treatment methods are costly and cannot effectively utilize the soft soil of the foundation. Summary of the Invention

[0004] In view of the technical problems existing in the prior art, the purpose of this invention is to provide a solid waste granular pile composite foundation structure and its construction method, so as to solve the problems of high cost and ineffective utilization of soft soil in existing soft soil foundation treatment methods.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A solid waste granular pile composite foundation structure, suitable for soft soil foundations, comprises: several granular piles distributed in a rectangular or quincunx pattern on the soft soil foundation, all granular piles having their surfaces covered with geogrids, and soft soil filling the spaces between adjacent granular piles; concealed piles, which are installed inside the granular piles, with their surfaces covered with geogrids, and soft soil filling the spaces between the concealed piles and the granular piles; and a connecting strip, which connects all the granular piles to form a connecting grid layer, with its surface covered with geogrids; the granular piles and the connecting strip are both composed of solid waste materials and water-absorbing and expanding resin.

[0007] As a preferred embodiment, there are multiple connecting grid layers, which are distributed at intervals along the depth direction of the granular pile.

[0008] As a preferred option, the maximum particle size of the solid waste material is 10 cm.

[0009] As a preferred option, the solid waste material is formed by mixing one or more of the following materials: construction waste, slag, steel slag, and furnace slag.

[0010] As a preferred option, the constituent materials of the granular pile also include cementitious materials, the mass of which does not exceed 10% of the mass of the solid waste materials.

[0011] As a preferred option, there are multiple hidden piles, which are evenly distributed within the loose pile.

[0012] As a preferred option, the cross-section of the granular pile is circular.

[0013] A construction method for a solid waste granular pile composite foundation structure includes the following implementation steps:

[0014] S1: Before designing the composite foundation, conduct an investigation of the soft soil foundation, and record the data on the water content, density, compression modulus, cohesion, internal friction angle and bearing capacity of the soft soil foundation. Based on the pre-set bearing capacity and deformation characteristics requirements of the composite foundation, determine the type of solid waste material and the quality of water-absorbing and expanding resin.

[0015] S2: Leveling the construction site for soft soil foundation;

[0016] S3: Measure the plan dimensions of the soft soil foundation, determine the location of the pile holes to be installed, and arrange all the pile holes of the loose soil piles in a square or quincunx pattern on the soft soil foundation, with a pile hole spacing of 2m.

[0017] S4: Drill hidden pile holes at the determined locations of each loose pile hole.

[0018] S5: Excavate the annular zone of the loose-body pile at the pile hole location;

[0019] S6: A geogrid conforming to the surface shape of the excavated loose pile is sunk into the annular zone of the loose pile to wrap the loose pile; a geogrid conforming to the surface shape of the hidden pile is sunk into the pile hole to wrap the hidden pile.

[0020] S7: Excavate connecting channels for loose piles in soft soil foundations, connecting channels to annular zones that connect all loose piles;

[0021] S8: While filling the pile hole of the granular pile with solid waste material and water-absorbing and expanding resin, a connecting strip with a geogrid wrapped on the surface is set in the connecting channel to connect the granular pile. The connecting strip is set at intervals along the depth direction of the granular pile in the connecting channel. The connecting strips located on the same plane form a connecting grid layer in the connecting channel.

[0022] S9: Repeat steps S3-S8 until all loose piles and connecting mesh layers are completed;

[0023] S10: Monitor the bearing capacity and deformation parameters of the composite foundation. After the deformation parameters stabilize, level and compact the site to complete the construction of the composite foundation structure.

[0024] In summary, the present invention has the following advantages:

[0025] The solid waste granular pile composite foundation structure and construction method of this invention address the shortcomings of current soft soil foundation treatment processes. It uses granular piles with solid waste materials and water-absorbing and expanding resin as pile materials to treat the foundation. The granular piles are connected by a geogrid wrapped with a connecting strip formed by solid waste materials and water-absorbing and expanding resin. By utilizing the water-absorbing and expanding characteristics of the resin, the water content of the soft soil between the piles is reduced and the strength of the soft soil between the piles is increased. At the same time, the expansion effect of the resin increases the diameter of the granular piles and tightens the connecting strip between the piles, so that the granular piles and the soft soil between the piles form a composite foundation, thereby reinforcing the soft soil foundation. Attached Figure Description

[0026] Figure 1 This is a three-dimensional side view of a single loose pile and its connecting strip in a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 1).

[0027] Figure 2 This is a three-dimensional side view of a single loose pile and its connecting strip in a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 5).

[0028] Figure 3 This is a cross-sectional view along line A-A' (with one hidden pile).

[0029] Figure 4 This is a cross-sectional view of section B-B'.

[0030] Figure 5 This is a plan view of a square arrangement of a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 1).

[0031] Figure 6 This is a plan view of a square arrangement of a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 5).

[0032] Figure 7 This is a plan view of a quincunx arrangement of a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 1).

[0033] Figure 8 This is a plan view of a quincunx arrangement of a solid waste loose pile composite foundation structure according to the present invention (the number of hidden piles is 5).

[0034] Figure 9 This is an elevation view of a solid waste bulk pile composite foundation structure according to the present invention.

[0035] Figure 10 This is a cross-sectional view along line C-C'.

[0036] Figure 11 This is a cross-sectional view of D-D'.

[0037] In the figure: 1. Loose pile, 101. Loose pile filling material, 102. Geogrid wrapping the loose pile, 2. Hidden pile, 201. Hidden pile filling material, 202. Connecting strip, 3. Connecting strip filling material, 301. Geogrid wrapping the connecting strip, 302. Soft soil between piles, 4. Detailed Implementation

[0038] The present invention will now be described in further detail with reference to specific embodiments.

[0039] like Figure 1-11 As shown, this embodiment provides a solid waste granular pile 1 composite foundation structure, including granular pile 1, concealed pile 2, and connecting strip 3. The outer wall of granular pile 1 is wrapped with geogrid, and the outer wall of concealed pile 2 is also wrapped with geogrid. Soft soil from a soft soil foundation is filled between granular pile 1 and concealed pile 2. The granular pile 1 is composed of solid waste material and water-absorbing and expanding resin. The solid waste material is composed of one or more materials such as construction waste, slag, steel slag, and furnace slag, and the maximum particle size of the solid waste material is 10 cm. Cementitious material can also be added to the granular pile 1, and the mass of the added cementitious material does not exceed 10% of the mass of the solid waste material. The pile hole of granular pile 1 is annular. If one concealed pile 2 is installed, the outer diameter of granular pile 1 is 80 cm, the thickness is 15 cm, and a concealed pile 2 with a diameter of 15 cm is installed at its center. Figure 1 If there are 5 hidden piles, the outer ring diameter of the loose pile 1 is 150cm and the thickness is 30cm, and a hidden pile 2 with a diameter of 15cm is installed inside it. Figure 2 Both have a depth of 5m to 20m. Several loose-body pile 1 holes are arranged in a square pattern on the soft soil foundation. Figure 5 , Figure 6 Or a plum blossom pattern arrangement ( Figure 7 , Figure 8 The spacing between the loose piles 1 is 2m. The loose piles 1 set up by the above method can make full use of solid waste materials, and at the same time use water-absorbing and expanding resin to absorb the water content of soft soil, and increase the diameter of the pile body through its expansion effect, thereby tightening the connecting strip 3 connected around the loose piles 1.

[0040] Taking a square arrangement of loose-body piles 1 as an example, the combination of a single loose-body pile 1 and the connecting strip 3 is as follows: Figure 1 , 2 As shown.

[0041] The outer surface of the connecting strip 3 is wrapped with geogrid. The connecting strip 3 is used to connect adjacent loose piles 1. The connecting strip 3 is perpendicular to the loose pile 1 and is in the same plane. There are four connecting strips 3 connected to the loose pile 1, and the four connecting strips 3 are evenly distributed around the circumference of the loose pile 1. The cross-section of the connecting strip is a square of 10cm × 10cm. Figure 4 The length of the connecting strip 3 is the pile spacing. All the connecting strips 3 form a connecting grid layer in the same plane. The connecting grid layer connects all the loose piles 1 to form a whole, which not only tightens all the loose piles 1, but also tightens the soft soil between the loose piles 1.

[0042] Three connecting grid layers can be set, located at 1 / 4, 1 / 2, and 3 / 4 of the length of the granular pile 1, respectively. For foundations with shallow soft soil, a granular pile 1 containing one hidden pile 2 can be used. Figure 1 For foundations with a large thickness of soft soil, a loose pile system containing 5 hidden piles can be used. Figure 2 ).

[0043] like Figure 3 As shown, the loose pile 1 is composed of a loose pile filling material 101 of solid waste material and water-absorbing and expanding resin and a geogrid 102 that wraps the loose pile; the hidden pile 2 is composed of a hidden pile filling material 201 of solid waste material and water-absorbing and expanding resin and a geogrid 202 that wraps the hidden pile; and the connecting strip 3 is composed of a connecting strip filling material 301 of solid waste material and water-absorbing and expanding resin and a geogrid 302 that wraps the connecting strip. After the water-absorbing and expanding resin in the solid waste material and water-absorbing and expanding resin granular pile filling material 101, the hidden pile filling material 201, and the connecting strip filling material 301 absorbs water and solidifies, the volume of the granular pile 1, the hidden pile 2, and the connecting strip 3 expands, thereby tightening the geogrid wrapped around the outer wall, so that the granular pile 1, the hidden pile 2, the connecting strip 3 and the soft soil 4 between the piles form a composite foundation. The water absorption and expansion effect of the water-absorbing and expanding resin in the mixture of solid waste material and water-absorbing and expanding resin can reduce the water content of the soft soil 4 between the piles and at the same time increase the strength of the soft soil 4 between the piles.

[0044] This embodiment of the composite foundation structure utilizes loose piles 1 made of solid waste materials driven into a soft soil foundation and connected by geogrids to reinforce the soft soil 4 between the piles 1. This allows the loose piles 1 and the soft soil 4 to work together to form a composite foundation. The water-absorbing and swelling resin in the loose piles 1 and the connecting strips expands after absorbing water, reducing the water content of the soft soil 4 and increasing its strength. The resulting composite foundation not only reinforces the soft soil 4 but also fully utilizes the inherent strength of the soft soil, exhibiting significant resistance to vertical and horizontal deformation. The loose piles 1 primarily utilize solid waste materials such as construction waste, slag, steel slag, and furnace slag, saving resources and reducing costs.

[0045] This embodiment also provides a construction method for a solid waste granular pile 1 composite foundation structure, taking a three-layer connected grid layer solid waste granular pile 1 composite foundation structure as an example, including the following steps:

[0046] First, conduct an investigation of the soft soil foundation to understand its moisture content, density, compression modulus, cohesion, internal friction angle, and bearing capacity related physical and mechanical parameters and engineering characteristics. Based on the design requirements for the bearing capacity and deformation characteristics of the reinforced composite foundation, determine the type of solid waste material and the quality of the water-absorbing and expanding resin.

[0047] Second, level the construction site for the composite foundation and prepare single-head rotary trenching machine and multi-head rotary trenching machine.

[0048] Third, measure the planar dimensions of the soft soil foundation, determine the location of the pile holes for the loose-body piles 1 to be installed, and arrange all the pile holes of loose-body piles 1 in a square or quincunx pattern on the soft soil foundation, with a pile hole spacing of 2m.

[0049] Fourth, at the determined locations of each loose pile 1 hole, drive 2 holes for hidden piles; use a single-head rotary trenching machine to excavate to the designed depth.

[0050] Fifth, excavate the annular zone of the loose pile 1 at the pile hole location on the soft soil foundation: use a multi-head rotary trenching machine to excavate to the design depth.

[0051] Sixth, a geogrid conforming to the surface shape of the excavated loose pile 1 is sunk into the annular zone to wrap the loose pile 1; a geogrid conforming to the surface shape of the hidden pile 2 is sunk into the pile hole of the hidden pile 2 to wrap the hidden pile 2.

[0052] Seventh: Excavate the connecting channel of loose pile 1 in the soft soil foundation. The connecting channel connects the annular zone of all loose pile 1. Use a long-arm excavator for mechanical excavation to dig to a depth of 1 / 4 pile length from the bottom of the pile.

[0053] Eighth, fill the pile hole with solid waste material and water-absorbing expanding resin until 1 / 4 pile length depth from the bottom of the pile, and set a connecting strip with a geogrid surface to connect the loose pile 1 at the connecting channel at 1 / 4 pile length depth from the bottom of the pile;

[0054] Ninth, backfill soft soil to 1 / 2 pile length depth, at which point a connecting strip with a geogrid surface is installed to connect the loose pile 1, and fill the pile hole of the loose pile 1 with solid waste material and water-absorbing expanding resin, and continue backfilling soft soil to 3 / 4 pile length, at which point a connecting strip with a geogrid surface is installed to connect the loose pile 1, and fill the pile hole of the loose pile 1 with solid waste material and water-absorbing expanding resin, and finally backfill soft soil to the top of the pile;

[0055] Tenth, repeat steps four through nine until all the loose piles 1 and connecting strips 3 are installed. The connecting strips on the same plane form a connecting grid layer in the connecting channel, and the connecting grid layer connects all the loose piles 1 into one.

[0056] Eleventh, monitor the site's bearing capacity and deformation parameters. Once the deformation parameters have stabilized, level and compact the site to complete the construction of the composite foundation structure.

[0057] The single-head rotary trenching machine and multi-head rotary trenching machine used above are both rotary trenching machines. Rotary trenching machines cause less disturbance to the trench wall, resulting in a smooth trench wall, more precise trench dimensions, high efficiency, and no noise. They require fewer on-site workers, ensuring safer operation and more civilized construction. They are suitable for geological conditions such as soft clay, sandy soil, and small-particle gravel layers. The cross-sectional boundary of the loose-body pile 1 during on-site excavation may be winding and tortuous. This is a result of the irregularity of the solid waste material and will not affect the final reinforcement effect of the loose-body pile 1. Invention principle: After the granular pile 1 is formed, the water-absorbing and expanding resin absorbs the moisture in the soft soil 4 between the piles and expands in volume, thereby increasing the diameter of the granular pile 1. This tightens the connecting band 3 that connects the granular piles 1, causing the soft soil 4 between the piles to be subjected to both drainage consolidation and compression. Ultimately, this improves the strength of the soft soil 4 between the piles and reinforces the foundation. The water-absorbing and expanding effect of the water-absorbing and expanding resin can fill the gaps between the granular pile 1 and the soft soil 4 between the piles, while reducing the water content of the soft soil 4 between the piles and increasing the strength of both the granular pile 1 and the soft soil 4 between the piles.

[0058] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A solid waste bulk pile composite foundation structure, the composite foundation structure being suitable for use on a soft ground foundation; characterised in that, include: Several loose piles are distributed in a rectangular or quincunx pattern on the soft soil foundation. The surface of all loose piles is covered with geogrid, and soft soil is filled between adjacent loose piles. The hidden pile is set inside the loose pile. The filling material of the hidden pile is composed of solid waste material and water-absorbing and expanding resin. The surface of the hidden pile is wrapped with geogrid. Soft soil is filled between the hidden pile and the loose pile. Connecting strips connect all the loose piles to form a connecting grid layer; the surface of the connecting strips is wrapped with geogrid. The components of both the loose-body piles and the connecting strips include solid waste materials and water-absorbing and expanding resin. The connecting strips are perpendicular to the loose piles and are in the same plane. There are four connecting strips that connect to the loose piles. The four connecting strips are evenly distributed around the circumference of the loose piles. All the connecting strips form a connecting grid layer in the same plane. The connecting grid layer connects all the loose piles to form a whole. There are three connecting grid layers. The three connecting grid layers are located at 1 / 4, 1 / 2 and 3 / 4 of the length of the loose pile, respectively.

2. A solid waste dispersion pile composite foundation structure according to claim 1, characterized in that: There are multiple connecting grid layers, which are distributed at intervals along the depth direction of the granular pile.

3. A solid waste granular pile composite foundation structure according to claim 1, characterized in that: The maximum particle size of solid waste materials is 10 cm.

4. A solid waste granular pile composite foundation structure according to claim 2, characterized in that: Solid waste materials are formed by mixing one or more of the following materials: construction waste, slag, steel slag, and furnace slag.

5. A solid waste granular pile composite foundation structure according to claim 2, characterized in that: The constituent materials of the loose-body pile also include cementitious materials, the mass of which does not exceed 10% of the mass of the solid waste materials.

6. A solid waste granular pile composite foundation structure according to claim 1, characterized in that: There are multiple hidden piles, which are evenly distributed within the loose piles.

7. A solid waste granular pile composite foundation structure according to claim 1, characterized in that: The cross-section of the loose-body pile is circular.

8. A construction method for a solid waste granular pile composite foundation structure according to any one of claims 1-7, characterized in that, The implementation steps include the following: S1: Before designing the composite foundation, conduct an investigation of the soft soil foundation, and record the data on the water content, density, compression modulus, cohesion, internal friction angle and bearing capacity of the soft soil foundation. Based on the pre-set bearing capacity and deformation characteristics requirements of the composite foundation, determine the type of solid waste material and the quality of water-absorbing and expanding resin. S2: Leveling the construction site for soft soil foundation; S3: Measure the plan dimensions of the soft soil foundation, determine the location of the pile holes to be installed, and arrange all the pile holes of the loose soil piles in a square or quincunx pattern on the soft soil foundation, with a pile hole spacing of 2m. S4: Drill hidden pile holes at the determined locations of each loose pile hole. S5: Excavate the annular zone of the loose-body pile at the pile hole location; S6: A geogrid that conforms to the shape of the surface of the loose pile is sunk into the annular zone of the excavated loose pile to wrap the loose pile. A geogrid that conforms to the shape of the surface of the hidden pile is inserted into the pile hole to wrap the hidden pile. S7: Excavate connecting channels for loose piles in soft soil foundations, connecting channels to annular zones that connect all loose piles; S8: While filling the pile hole of the granular pile with solid waste material and water-absorbing and expanding resin, a connecting strip with a geogrid wrapped on the surface is set in the connecting channel to connect the granular pile. The connecting strip is set at intervals along the depth direction of the granular pile in the connecting channel. The connecting strips located on the same plane form a connecting grid layer in the connecting channel. S9: Repeat steps S3-S8 until all loose piles and connecting mesh layers are completed; S10: Monitor the bearing capacity and deformation parameters of the composite foundation. After the deformation parameters stabilize, level and compact the site to complete the construction of the composite foundation structure.

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