A wet curing settlement-reducing foundation construction process

Abstract

The application provides a wet curing subsidence-reducing foundation construction process, which comprises the following steps: leveling a foundation site and excavating a foundation pit, simultaneously excavating at least one group of extrusion pits at the bottom of the foundation pit; after the extrusion pits are excavated at the bottom of the foundation pit, the extrusion pits are left overnight, then water in the extrusion pits is pumped out by using a water pump, extrusion cushion layers are poured into the extrusion pits, and a first point ramming is performed by using a rammer, wherein the edge of a second hammer is tangent to the center point of a first hammer during the point ramming; after the first point ramming is completed, backfilling soil is added to the extrusion pits at intervals of 2-3 days for backfilling, and a second point ramming is performed by using the rammer; after the second point ramming is completed, the extrusion pits are backfilled to be flush with the bottom of the foundation pit, then pile foundations are constructed between adjacent two groups of extrusion cushion layers; a pile cap is constructed in the foundation pit through the pile foundations, and the pile cap is backfilled and leveled around, the construction period of the application is short, the foundation is independent of the region outside, and the soil layer of the building region is effectively prevented from eroding the foundation.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of building construction, in particular to a wet curing settlement-reducing foundation construction process. BACKGROUND

[0002] Collapsible loess is an unsaturated under-compacted soil with large pores and vertical joints. Under natural humidity, its compressibility is low and its strength is high, but when it is soaked with water, the strength of the soil decreases significantly, and under additional pressure or under additional pressure and the self-weight pressure of the soil, it causes collapsible deformation, which is a large amount of subsidence and fast subsidence speed, and is a destabilizing deformation that is harmful to buildings. Currently, in the treatment of collapsible loess foundation, the commonly used treatment methods are: cushion method, dynamic compaction method, compaction method and pre-soaking method, etc. These methods have certain limitations.

[0003] Currently, the treatment period of the collapsible loess foundation treatment method is long, and the foundation has not been well supported in the horizontal direction; and because the surrounding of the foundation is collapsible loess, the surrounding soil will migrate and then continuously erode the foundation, which will cause serious harm to the buildings on the foundation. SUMMARY

[0004] (I) Technical problems solved

[0005] In view of the deficiencies of the prior art, the present application provides a wet curing settlement-reducing foundation construction process, comprising the following steps:

[0006] Step one: after leveling the foundation site, excavate the foundation pit, and at the same time, excavate at least one group of extrusion pits at the bottom of the foundation pit;

[0007] Step two: after excavating the extrusion pit at the bottom of the foundation pit, leave it overnight, then use a water pump to pump out the water inside the extrusion pit, then pour the extrusion cushion into the extrusion pit, and at the same time, use a rammer to perform a first point ramming, and the edge of the second hammer is tangent to the center point of the first hammer during point ramming;

[0008] Step three: after the first point ramming is completed, add backfill soil to the inside of the extrusion pit after 2-3 days, and at the same time, use a rammer to perform a second point ramming;

[0009] Step four: after the second point ramming is completed, backfill the extrusion pit to the bottom of the foundation pit, and then build a pile foundation between the adjacent two groups of extrusion cushions;

[0010] Step five: build a pile cap inside the foundation pit through the pile foundation, and backfill and level around the pile cap.

[0011] As a further optimization, the depth of the foundation pit in step one is 4.0-5.2m, the vertical section of the extrusion pit is bullet-shaped, and the width of the extrusion pit is 2m, and the distance between the adjacent two groups of extrusion pits is 3m.

[0012] As a further preferred option, when excavating the squeezing pit inside the foundation pit, the construction area of ​​the squeezing pit will be marked out in advance using lime inside the foundation pit. In step one, when excavating the squeezing pit inside the foundation pit, the excavation will proceed from both sides of the foundation pit towards the middle, and the excavation efficiency of the squeezing pit will be accelerated by starting work on both sides at the same time.

[0013] As a further preferred option, after all the water inside the extrusion pit is pumped out, a heater and a blower are used to dry the moisture on the inner wall of the extrusion pit.

[0014] As a further preferred option, the extrusion pad in step two is specifically a mixture of construction waste and lime, and the ratio of construction waste to lime is 100 to 1000:1. The construction waste is specifically aggregate obtained from demolition, such as concrete slag and brick and stone slag, after being crushed by a crusher.

[0015] As a further preferred option, in step three, after the initial compaction is completed, water is sprayed on top of the compacted extrusion pad, with the amount of water being 0.01% of the volume of the extrusion pad.

[0016] By using the above technical solution, the soil generated from the excavation of the foundation pit and squeezing pit can be retained as backup backfill soil, which saves costs and improves construction efficiency.

[0017] (II) Beneficial Effects

[0018] This invention provides a wet-solidification and settlement reduction foundation construction process with the following beneficial effects: By excavating a foundation pit, and then excavating squeezing pits at intervals at the bottom of the pit, groundwater enters the squeezing pits. The groundwater accumulated inside the squeezing pits replenishes the soil layer. The intervals between the squeezing pits allow for faster water infiltration into the soil layers on adjacent sides. After the soil layer is soaked, the water in the squeezing pits can be directly pumped out. The remaining water in the soil layer adjacent to the squeezing pits is partially absorbed by the addition of a squeezing cushion layer. The squeezing cushion layer solidifies into a single unit after absorbing water, and with its compaction, the two sets of squeezing cushion layers compress the adjacent soil layers, increasing the compressive and shear strength of the foundation and effectively preventing soil deformation between the two sets of squeezing cushion layers. Furthermore, the structural strength of the squeezing cushion layer is superior to that of the soil layer. The squeezing cushion layer provides excellent horizontal support for the pile foundation within the soil layer. The squeezing cushion layer effectively prevents the subsidence of the soil layer around the foundation pit from affecting the pile foundation, making the soil layer inside the foundation pit independent of the soil layer in the construction area, further improving the foundation treatment effect. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the first step of the foundation construction process of the present invention;

[0020] Figure 2 This is a schematic diagram of steps two and three of the foundation construction process of the present invention;

[0021] Figure 3 for Figure 2 Schematic diagram of the bottom of the foundation pit;

[0022] Figure 4 This is a schematic diagram of step four of the foundation construction process of the present invention;

[0023] Figure 5 for Figure 4 Schematic diagram of the bottom of the foundation pit;

[0024] Figure 6 This is a schematic diagram of step five of the foundation construction process of the present invention.

[0025] In the diagram: 1. Excavation pit, 2. Extrusion pit, 3. Extrusion cushion layer, 4. Pile foundation, 5. Pit cap. Detailed Implementation

[0026] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0027] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," and "counterclockwise," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of the stated features. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, an electrical connection, or a connection that allows for communication; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0029] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0030] The following disclosure provides many different embodiments or examples for implementing various structures of the invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0031] Example 1

[0032] This invention provides a wet-solidification and settlement reduction foundation construction process, including the following steps:

[0033] Step 1: After leveling the foundation site, measure the site elevation, and then excavate the foundation pit 1 according to the design drawings. After excavating the foundation pit 1, protect the edge of the pit. Then, at least one set of compression pits 2 are excavated at intervals at the bottom of the foundation pit 1. Select some of the soil produced by excavating the foundation pit 1 and the compression pit 2 and pile it around the foundation pit 1.

[0034] Step 2: After excavating the squeezing pit 2 inside the foundation pit 1, leave it overnight. Natural water seepage will occur inside the squeezing pit 2. Then, use a water pump to pump out the water inside the squeezing pit 2, and pour the squeezing pad 3 into the squeezing pit 2. At the same time, use a tamping hammer to perform a point tamping. When tamping, the edge of the second hammer is tangent to the center point of the first hammer. In this embodiment, the tamping machine used is a 3150KN.m dynamic tamping machine with a hammer diameter of 1.8m and a hammer drop height of 15m.

[0035] Step 3: After the first tack is completed, add backfill soil into the squeezing pit 2 after an interval of 2-3 days. At the same time, use a tamping hammer to perform a second tack. The direction of the second tack is opposite to that of the first tack. That is, the first tack is from left to right, and the second tack is from right to left. The parameters of the first tack and the second tack are the same.

[0036] Step 4: After the secondary compaction is completed, the extrusion pit 2 is backfilled to be level with the bottom of the foundation pit. The backfill is made from the soil excavated from foundation pit 1 and extrusion pit 2. After backfilling, the backfill soil is compacted with a roller. Then, pile foundation 4 is constructed between the two adjacent sets of extrusion cushion layers 3. The depth of pile foundation 4 is not deeper than the lowest point of extrusion pit 2.

[0037] Step 5: Construct a pile cap 5 inside the foundation pit 1 using pile foundation 4, and backfill and level the area around the pile cap 5. The backfill soil is the soil excavated from the foundation pit 1 and the squeezing pit 2.

[0038] After step five is completed, the foundation quality must be inspected in accordance with the "Code for Building Construction in Collapsible Loess Areas GB50025-2004" and design requirements, the collapsibility of the foundation soil must be reassessed, and the project must be completed and accepted in accordance with relevant standards.

[0039] In this embodiment, the depth of the foundation pit in step one is 4.0-5.2m, the vertical cross-section of the squeezing pit 2 is bullet-shaped, the width of the squeezing pit 2 is 2m, the distance between two adjacent squeezing pits 2 is 3m, after the squeezing pit 2 is excavated, the water in the soil layer between adjacent squeezing pits 2 will naturally seep into the squeezing pit 2, and the water accumulated inside the squeezing pit 2 will in turn drive the soil layer between adjacent squeezing pits 2 to absorb water and settle, thereby achieving the purpose of reinforcing and compacting the soil layer.

[0040] When excavating the squeezing pit 2 inside the foundation pit 1, the construction area of ​​the squeezing pit 2 will be marked out in advance inside the foundation pit 1 using lime. In step one, when excavating the squeezing pit 2 inside the foundation pit 1, the excavation will proceed from both sides of the foundation pit 1 towards the middle. By starting work on both sides simultaneously, the excavation efficiency of the squeezing pit 2 will be accelerated.

[0041] In this embodiment, after all the water inside the extrusion pit 2 is pumped out, a heater and a fan are used to dry the water on the inner wall of the extrusion pit 2. By drying the inner wall of the extrusion pit 2 first, it is easier to prevent the extrusion pad 3 from absorbing water and solidifying immediately after it is filled in.

[0042] In this embodiment, the extrusion cushion layer 3 in step two is specifically a mixture of construction waste and lime, with a ratio of 100 to 1000:1. The construction waste specifically refers to aggregates obtained from demolition, such as concrete slag and brick and stone slag, after being crushed by a crusher. Construction waste is essentially unusable construction waste, but it has a compact structure. After being mixed with lime, it becomes absorbent, and its structural strength is further improved after absorbing water, while also reducing costs. Furthermore, the mass of the extrusion cushion layer 3 after solidification is greater than that of the soil layer. When encountering subsidence in deeper soil layers, the extrusion cushion layer 3 will subside first. After the extrusion cushion layer 3 subsides, it will compress the adjacent soil layer, ensuring that the soil layer at the pile foundation construction location maintains a high strength, thereby preventing subsidence of the soil layer during pile foundation construction.

[0043] Among them, the compression cushion layer 3 will solidify into one piece after absorbing water. In addition, it will be compacted. The two sets of compression cushion layers 3 will squeeze the soil layer on the adjacent side, increase the compressive and shear resistance of the foundation, effectively prevent the soil layer between the two sets of compression cushion layers 3 from deforming. Moreover, the structural strength of the compression cushion layer 3 is better than that of the soil layer. The compression cushion layer 3 will have a good horizontal support effect on the pile foundation 4 in the soil layer. The compression cushion layer 3 can effectively prevent the soil layer around the foundation pit 1 from affecting the pile foundation 4, making the soil layer inside the foundation pit 1 independent from the soil layer in the construction area, and further improving the foundation treatment effect.

[0044] In this embodiment, in step three, after the first tamping is completed, water is sprayed on the top of the tamped extrusion pad 3. The amount of water sprayed is 0.01% of the volume of the extrusion pad 3. By spraying water on the surface of the extrusion pad 3, the solidification speed of the extrusion pad 3 can be accelerated and the engineering efficiency can be improved.

[0045] Example 2

[0046] This invention provides a wet-solidification and settlement reduction foundation construction process, including the following steps:

[0047] Step 1: After leveling the foundation site, measure the site elevation, and then excavate the foundation pit 1 according to the design drawings. After excavating the foundation pit 1, protect the edge of the pit. Then, at least one set of compression pits 2 are excavated at intervals at the bottom of the foundation pit 1. Select some of the soil produced by excavating the foundation pit 1 and the compression pit 2 and pile it around the foundation pit 1.

[0048] Step 2: After excavating the squeezing pit 2 inside the foundation pit 1, leave it overnight. Natural water seepage will occur inside the squeezing pit 2. Then, use a water pump to pump out the water inside the squeezing pit 2, and pour the squeezing pad 3 into the squeezing pit 2. At the same time, use a tamping hammer to perform a point tamping. When tamping, the edge of the second hammer is tangent to the center point of the first hammer. In this embodiment, the tamping machine used is a 3150KN.m dynamic tamping machine with a hammer diameter of 1.8m and a hammer drop height of 15m.

[0049] Step 3: After the first tack is completed, add backfill soil into the squeezing pit 2 after an interval of 2-3 days. At the same time, use a tamping hammer to perform a second tack. The direction of the second tack is opposite to that of the first tack. That is, the first tack is from left to right, and the second tack is from right to left. The parameters of the first tack and the second tack are the same.

[0050] Step 4: After the secondary compaction is completed, continue to add the extrusion pad 3 and compact it until the extrusion pad 3 inside the extrusion pit 2 is level with the bottom of the foundation pit 1. Then, construct the pile foundation 4 between the two adjacent sets of extrusion pads 3. The depth of the pile foundation 4 is not deeper than the lowest point of the extrusion pit 2.

[0051] Step 5: Construct a pile cap 5 inside the foundation pit 1 using pile foundation 4, and backfill and level the area around the pile cap 5. The backfill soil is the soil excavated from the foundation pit 1 and the squeezing pit 2.

[0052] After step five is completed, the foundation quality must be inspected in accordance with the "Code for Building Construction in Collapsible Loess Areas GB50025-2004" and design requirements, the collapsibility of the foundation soil must be reassessed, and the project must be completed and accepted in accordance with relevant standards.

[0053] In this embodiment, the depth of the foundation pit in step one is 4.0-5.2m, the vertical cross-section of the squeezing pit 2 is bullet-shaped, the width of the squeezing pit 2 is 2m, the distance between two adjacent squeezing pits 2 is 3m, after the squeezing pit 2 is excavated, the water in the soil layer between adjacent squeezing pits 2 will naturally seep into the squeezing pit 2, and the water accumulated inside the squeezing pit 2 will in turn drive the soil layer between adjacent squeezing pits 2 to absorb water and settle, thereby achieving the purpose of reinforcing and compacting the soil layer.

[0054] When excavating the squeezing pit 2 inside the foundation pit 1, the construction area of ​​the squeezing pit 2 will be marked out in advance inside the foundation pit 1 using lime. In step one, when excavating the squeezing pit 2 inside the foundation pit 1, the excavation will proceed from both sides of the foundation pit 1 towards the middle. By starting work on both sides simultaneously, the excavation efficiency of the squeezing pit 2 will be accelerated.

[0055] In this embodiment, after all the water inside the extrusion pit 2 is pumped out, a heater and a fan are used to dry the water on the inner wall of the extrusion pit 2. By drying the inner wall of the extrusion pit 2 first, it is easier to prevent the extrusion pad 3 from absorbing water and solidifying immediately after it is filled in.

[0056] In this embodiment, the extrusion cushion layer 3 in step two is specifically a mixture of construction waste and lime, with a ratio of 100 to 1000:1. The construction waste specifically refers to aggregates obtained from demolition, such as concrete slag and brick and stone slag, after being crushed by a crusher. Construction waste is essentially unusable construction waste, but it has a compact structure. After being mixed with lime, it becomes absorbent, and its structural strength is further improved after absorbing water, while also reducing costs. Furthermore, the mass of the extrusion cushion layer 3 after solidification is greater than that of the soil layer. When encountering subsidence in deeper soil layers, the extrusion cushion layer 3 will subside first. After the extrusion cushion layer 3 subsides, it will compress the adjacent soil layer, ensuring that the soil layer at the pile foundation construction location maintains a high strength, thereby preventing subsidence of the soil layer during pile foundation construction.

[0057] Among them, the compression cushion layer 3 will solidify into one piece after absorbing water. In addition, it will be compacted. The two sets of compression cushion layers 3 will squeeze the soil layer on the adjacent side, increase the compressive and shear resistance of the foundation, effectively prevent the soil layer between the two sets of compression cushion layers 3 from deforming. Moreover, the structural strength of the compression cushion layer 3 is better than that of the soil layer. The compression cushion layer 3 will have a good horizontal support effect on the pile foundation 4 in the soil layer. The compression cushion layer 3 can effectively prevent the soil layer around the foundation pit 1 from affecting the pile foundation 4, making the soil layer inside the foundation pit 1 independent from the soil layer in the construction area, and further improving the foundation treatment effect.

[0058] In this embodiment, in step three, after the first tamping is completed, water is sprayed on the top of the tamped extrusion pad 3. The amount of water sprayed is 0.01% of the volume of the extrusion pad 3. By spraying water on the surface of the extrusion pad 3, the solidification speed of the extrusion pad 3 can be accelerated and the engineering efficiency can be improved.

[0059] In summary, the wet-solidification and settlement reduction foundation construction process provided by this invention involves excavating a foundation pit 1, and then excavating squeezing pits 2 at intervals at the bottom of the foundation pit 1. This allows groundwater to enter the squeezing pits 2, and the groundwater accumulated inside the squeezing pits 2 will replenish the soil layer. Furthermore, the squeezing pits 2 are excavated at intervals, allowing for faster water infiltration into the soil layers on adjacent sides of multiple sets of squeezing pits 2. After the soil layer is soaked, the water in the squeezing pits 2 can be directly pumped out. The remaining water in the soil layers adjacent to the squeezing pits 2 will be partially absorbed after the addition of a squeezing pad layer 3. The squeezing pad layer 3 further absorbs... After being soaked in water, the material solidifies into a single unit. Combined with the compaction of the material, the two sets of compression cushion layers 3 will compress the soil layers on adjacent sides, increasing the compressive and shear strength of the material. This effectively prevents deformation of the soil layers between the two sets of compression cushion layers 3. Furthermore, the structural strength of the compression cushion layer 3 is superior to that of the soil layers. The compression cushion layer 3 provides excellent horizontal support for the pile foundation 4 within the soil layers. By using the compression cushion layer 3, the subsidence of the soil layers around the foundation pit 1 can be effectively prevented from affecting the pile foundation 4. This keeps the soil layers inside the foundation pit 1 independent from the soil layers in the construction area, further improving the foundation treatment effect.

[0060] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A wet-solidification and settlement reduction foundation construction process, characterized in that: Includes the following steps: Step 1: After leveling the foundation site, excavate the foundation pit (1), and at the same time, excavate at least one set of compression pits (2) at intervals at the bottom of the foundation pit (1); Step 2: After excavating the squeezing pit (2) at the bottom of the foundation pit (1), leave it overnight, then use a water pump to pump out the water inside the squeezing pit (2), and then pour the squeezing pad (3) into the squeezing pit (2), and at the same time use a tamping hammer to perform a point tamping. Step 3: After the first tamping is completed, add backfill soil into the squeezing pit (2) after an interval of 2-3 days, and at the same time use a tamping hammer to perform a second tamping. Step 4: After the secondary compaction is completed, the extrusion pit (2) is backfilled to be level with the bottom of the foundation pit, and then pile foundation (4) is constructed between the two adjacent sets of extrusion cushion layers (3); Step 5: Construct a pile cap (5) inside the foundation pit (1) using pile foundation (4), and backfill and level the area around the pile cap (5); In step two, the extruded pad (3) is specifically a mixture of construction waste and lime, and the ratio of construction waste to lime is 100 to 1000:1; In step three, after the first tack compaction is completed, water is sprayed on the top of the compacted extrusion pad (3), and the amount of water sprayed is 0.01% of the volume of the extrusion pad (3).

2. The wet-solidification and settlement reduction foundation construction process according to claim 1, characterized in that: In step one, the depth of the foundation pit is 4.0-5.2m, the vertical cross section of the extrusion pit (2) is bullet-shaped, the maximum width of the extrusion pit (2) is 2m, and the distance between two adjacent extrusion pits (2) is 3m.

3. The wet-solidification and settlement reduction foundation construction process according to claim 1, characterized in that: In step one, when excavating the compression pit (2) in the foundation pit (1), the excavation is carried out from both sides of the foundation pit (1) towards the middle.

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