Deep soft soil foundation differential settlement foundation treatment method

Abstract

The invention relates to the technical field of roadbed reinforcement, in particular to a deep soft soil foundation differential settlement foundation treatment method which comprises the following steps: exploring soft soil distribution and underground water conditions of a foundation position, and then treating a soft soil layer; arranging a layer of civil grids on the treated soft soil layer to isolate and block the soft soil; the upper layer of the civil grid is filled with a gravel cushion layer, and the gravel cushion layer is flattened and compacted; a layer of continuous reinforced concrete plate is poured on the surface of the gravel cushion layer, and the concrete plate is cured; after the continuous reinforced concrete slab reaches the design strength, a base layer is laid at the top end of the continuous reinforced concrete slab and is flattened and compacted; the top surface of the base layer is flattened, and then a surface layer is laid on the top surface of the base layer to serve as a walking pavement of the road. The structure is simple, the construction speed is high, the technology is mature, the construction speed is high, the construction cost is low, large professional piling equipment is not needed, the influence on the environment is small, and the soft soil foundation can be conveniently treated.

Description

Technical Field

[0001] This invention relates to the field of soft subgrade reinforcement technology, and in particular to a method for treating uneven settlement of deep soft soil foundations. Background Technology

[0002] Soft soil foundations have engineering characteristics such as high compressibility, low strength, high natural water content, large natural void ratio, low shear strength, and low permeability coefficient. If they are not treated or are treated improperly, they will lead to a reduction in the quality of the project or even its destruction, directly affecting the stability and safety of the project. In highway construction, it is crucial to deal with the complex soft soil foundation problem.

[0003] Traditional soft soil treatment methods include replacement, preloading, drainage consolidation, reinforced sand cushion, composite foundation, and chemical reinforcement, primarily promoting the consolidation of soft soil foundations and increasing the soil's bearing capacity. However, for the soft soil foundation structure in the Dongting Lake area, ordinary geogrid reinforcement cannot meet its load requirements, resulting in poor reinforcement effects and unreliable long-term performance of geosynthetics. Drainage consolidation has a long construction period, and vacuum preloading requires high sealing performance; if not handled carefully, it may fail to meet project needs. Composite foundation methods may present challenges in pile construction due to soft soil, resulting in significant differences in pile-soil stiffness and uneven load distribution. Under long-term action, pile top settlement is small, while inter-pile settlement is large. Along the route, changes in geological conditions or fluctuations in construction quality may lead to wave-like settlement, affecting driving comfort and road surface quality. Construction quality is highly variable, and the cost is relatively high with a long construction time. Chemical reinforcement methods use expensive curing agents, and the penetration and diffusion of the curing agent within the soil are difficult to control evenly, resulting in uneven reinforcement effects.

[0004] Therefore, it is urgent to design a method for treating uneven settlement of deep soft soil foundations to solve the above-mentioned technical problems. Summary of the Invention

[0005] The purpose of this invention is to provide a method for treating uneven settlement of deep soft soil foundations, so as to solve the problems existing in the prior art.

[0006] To achieve the above objectives, the present invention provides the following solution: The present invention provides a method for treating uneven settlement of deep soft soil foundations, comprising the following steps:

[0007] Explore the distribution of soft soil and groundwater conditions at the foundation location, and then treat the soft soil layer;

[0008] A layer of earth and wood grid is installed on the treated soft soil layer to isolate and block the soft soil.

[0009] A layer of gravel cushion is filled on top of the geogrid, and the gravel cushion is flat and compacted.

[0010] A continuous reinforced concrete slab is cast on the surface of the sand-gravel cushion, and the concrete slab is cured;

[0011] After the continuous reinforced concrete slab reaches the design strength, a base layer is laid on the top of the continuous reinforced concrete slab and is rolled and compacted;

[0012] The top surface of the base layer is leveled, and then a surface layer is laid on the top of the base layer as the road surface for walking.

[0013] Preferably, the process of treating the selected foundation site comprises the following steps:

[0014] Removing sundries on the surface of the selected foundation site;

[0015] Excavating the planting soil above the soft soil layer to expose the soft soil foundation;

[0016] Leveling and compacting the exposed soft soil foundation using engineering machinery.

[0017] Preferably, the process of treating the selected foundation site further comprises the following steps:

[0018] Analyzing the underground water and precipitation of the soft soil foundation site;

[0019] Constructing a temporary drainage ditch on the soft soil foundation.

[0020] Preferably, in the process of laying a layer of civil grid on the treated foundation, adjacent civil grids are connected by overlapping.

[0021] Preferably, in the process of filling a layer of sand-gravel cushion on the upper layer of the civil grid, the height of the sand-gravel cushion is 0.5-1m.

[0022] Preferably, in the process of filling a layer of sand-gravel cushion on the upper layer of the civil grid, the sand-gravel cushion is laid in layers, and each layer is compacted and leveled.

[0023] Preferably, the process of casting a continuous reinforced concrete slab on the surface of the sand-gravel cushion further comprises the following steps:

[0024] Supporting side formworks on the sand-gravel cushion, the size of the side formworks being adapted to the continuous reinforced concrete slab;

[0025] Bundling steel reinforcement frameworks in the side formworks in two directions as the framework of the continuous reinforced concrete slab;

[0026] Pouring concrete into the side formworks, vibrating and compacting the concrete, and troweling the surface;

[0027] Curing the concrete to harden the continuous reinforced concrete slab;

[0028] After the hardness of the concrete reaches the standard, the side formworks are removed.

[0029] Preferably, the process of pouring a layer of continuous reinforced concrete slab on the surface of the sand and gravel cushion further comprises the following steps:

[0030] The continuous reinforced concrete slab is continuously poured into a whole.

[0031] Preferably, the thickness of the continuous reinforced concrete slab is 8-10 cm.

[0032] Preferably, in the process of laying a layer of base on the top end of the continuous reinforced concrete slab, the thickness of the base is 30-50 cm.

[0033] Compared with the prior art, the present application has the following advantages and technical effects: the present application discloses a foundation treatment method for deep soft soil foundation uneven settlement, which combines the reinforcement method and the replacement method, and uses the civil grid, the sand and gravel cushion and the continuous reinforced concrete slab to reinforce the soft soil layer in three layers. The method is suitable for soft soil foundation treatment prone to slab breaking and uneven settlement. After geological survey, the soil layer is leveled to expose the soft soil layer, and the civil grid is laid on the upper part of the soft soil layer. The civil grid can effectively improve the shear resistance through the reinforcement effect, prevent sliding and tilting, and can also diffuse stress, effectively reinforcing and stabilizing the foundation. The sand and gravel cushion, as a stable foundation material, can provide a stable and solid support surface to ensure the long-term stability of the upper structure of the road. The sand and gravel cushion can play a good isolation role, isolate underground water siphon loss, ensure the underground water level, prevent soft soil consolidation, cause water level drop and roadbed deformation, thereby reducing settlement and cracks; and the sand and gravel cushion can improve the foundation resistance to underground water siphon loss, isolate underground water rise, cause foundation settlement, effectively prevent soft soil consolidation and foundation uneven settlement, and reduce the phenomenon of insufficient support force of the reinforced concrete bottom. On the basis of the reinforcement of the civil grid and the sand and gravel cushion, a layer of continuous reinforced concrete slab is laid to improve the structural bearing capacity and effectively reduce the pressure of local load, prevent local settlement, and is a treatment method for soft soil uneven settlement; and the continuous reinforced concrete slab can provide a stable working surface to ensure the stable operation of construction equipment and personnel on the soft soil foundation, improve the crack resistance and deformation resistance of the structure, resist crack expansion caused by external load, and ensure the safety of the upper structure. The continuous reinforced concrete slab can effectively combine with the sand and gravel cushion to form a complete foundation system, improve the uneven settlement of the structure as a whole and the durability of the road, avoid the occurrence of slab breaking and uneven settlement of highway engineering, and affect the normal use. The civil grid and the continuous reinforced concrete slab can effectively constrain the lateral deformation of the sand and gravel cushion and the soft soil, the continuous reinforced concrete slab forms a hard and flat surface, and the working surface is convenient for subsequent construction. The present application has the advantages of simple structure, fast construction speed, mature technology, fast construction speed, low construction cost, no need for large professional piling equipment, small environmental impact, and convenience for soft soil foundation treatment. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed in the embodiments. Obviously, the drawings described below only show some of the embodiments of the present application, and other drawings can be obtained by those of ordinary skill in the art without any creative effort based on these drawings. In the drawings:

[0035] Fig. 1 A schematic diagram of the present application for deep soft soil foundation uneven settlement foundation treatment method;

[0036] Fig. 2 A schematic diagram of the present application for continuous reinforced concrete slab;

[0037] In the figure: 1, soft soil layer; 2, civil grid; 3, sand and gravel cushion; 4, continuous reinforced concrete slab; 5, base layer; 6, surface layer; 7, side formwork; 8, steel reinforcement cage. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort belong to the scope of protection of the present application.

[0039] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0040] Referring to Figs. 1-2 The present embodiment provides a deep soft soil foundation uneven settlement foundation treatment method, comprising the following steps:

[0041] Exploring the soft soil distribution and groundwater conditions of the foundation position, and then treating the soft soil layer 1;

[0042] A layer of civil grid 2 is arranged on the treated soft soil layer 1 to isolate and block the soft soil;

[0043] A layer of sand and gravel cushion 3 is filled on the upper layer of the civil grid 2, and the sand and gravel cushion 3 is flattened and compacted;

[0044] A layer of continuous reinforced concrete slab 4 is poured on the surface of the sand and gravel cushion 3, and the concrete slab is cured;

[0045] After the continuous reinforced concrete slab 4 reaches the design strength, a layer of base layer 5 is laid on the top end of the continuous reinforced concrete slab 4, and is flattened and compacted;

[0046] The top surface of the base layer 5 is flattened, and then a layer of surface layer 6 is laid on the top surface of the base layer 5 as a road surface for walking.

[0047] The application discloses a deep soft soil foundation uneven settlement foundation treatment method, which adopts the combination of the reinforcement method and the replacement method, and three layers of the civil grid 2, the gravel cushion 3 and the continuous reinforced concrete slab 4 are superposed to reinforce the soft soil layer 1, and the method is used for treating the soft soil foundation prone to broken slab and uneven settlement. After geological exploration, the soil layer is flattened to expose the soft soil layer 1, the civil grid 2 is laid on the upper portion of the soft soil layer 1, the civil grid 2 can effectively improve the shearing capacity through the reinforcement effect, prevent sliding and tilting, and can diffuse stress, thereby effectively reinforcing and stabilizing the foundation. The gravel cushion 3 can provide a stable and solid supporting surface as a stable foundation material, and guarantees the long-term stability of the upper structure of the road. The gravel cushion 3 can play a good isolation role, isolate the deformation of the underground soft soil caused by the change of underground water of the soft soil, thereby reducing uneven settlement and cracks; and the gravel cushion 3 can improve the underground water permeability of the foundation, and effectively prevent the phenomenon of soft soil consolidation settlement. On the basis of the reinforcement of the civil grid 2 and the gravel cushion 3, a layer of the continuous reinforced concrete slab 4 is further laid, the structural bearing capacity is improved, the pressure of local load is effectively reduced, local settlement is prevented, and the method is used for treating the uneven settlement of the soft soil; and the continuous reinforced concrete slab 4 can provide a stable working surface, ensure the stable operation of construction equipment and personnel on the soft soil foundation, improve the crack resistance and deformation resistance of the structure, resist crack expansion caused by external load, and ensure the safety of the upper structure. The continuous reinforced concrete slab 4 can be effectively combined with the gravel cushion 3 to form a complete foundation system, improve the durability of the structure as a whole, avoid the occurrence of broken slab and uneven settlement of the road engineering, and affect the normal use. The civil grid 2 and the continuous reinforced concrete slab 4 can effectively constrain the lateral deformation of the gravel cushion 3 and the soft soil, the continuous reinforced concrete slab 4 forms a hard and flat surface, and the working surface is convenient for subsequent construction. The application has the advantages of simple structure, fast construction speed, mature technology, low construction cost, no need of large professional piling equipment, small influence on the environment, and convenience for treating the soft soil foundation.

[0048] In an embodiment of the application, the treatment of the soft soil foundation is mainly to improve the shearing and compressive strength of the foundation soil, reduce the compressibility of the foundation, guarantee the compression modulus of the foundation soil, and reduce the uneven settlement of the foundation. In addition, the permeability of the foundation needs to be prevented, the dynamic characteristics of the roadbed need to be improved, and the anti-seismic performance of the foundation needs to be improved. The development direction of the soft soil treatment foundation is gradually developing from a single reinforcement method to a multi-method composite form, gradually transitioning from high-energy consumption and high-pollution technology to new low-carbon technology, and realizing the harmonious development of human beings and nature.

[0049] Further optimization scheme, the process of processing the selected foundation position comprises the following steps: removing the sundries on the surface of the selected foundation position; digging off the planting soil above the soft soil layer 1 to expose the soft soil foundation; using engineering machinery to flatten and compact the exposed soft soil foundation. Remove the farmland soil on the ground to expose the soft soil layer, which facilitates subsequent processing; survey the geology of the soft soil layer area to understand the distribution of the soft soil and the groundwater conditions, and provide data support for the development of the soft soil foundation reinforcement scheme; finally, the soft soil layer 1 is rolled several times by a light roller and is flattened, so that the deformation modulus of the soft soil layer 1 is basically consistent.

[0050] Further optimization scheme, the process of processing the selected foundation position further comprises the following steps: analyzing the groundwater conditions of the soft soil foundation position.

[0051] Further optimization scheme, in the process of setting a layer of civil grid 2 on the processed foundation, the adjacent civil grids 2 are connected by overlapping. The adjacent civil grids 2 need to have sufficient overlapping width, and should be pulled tight and laid flat during paving to ensure good contact with the soft soil, thereby playing the roles of constraining gravel displacement, isolation, filtration, and preliminary drainage to prevent soft soil from surging and polluting the gravel layer.

[0052] Further optimization scheme, in the process of filling a layer of gravel cushion 3 on the upper layer of the civil grid 2, the height of the gravel cushion 3 is 0.5m-1m. The thickness of the gravel cushion 3 is selected according to actual needs, which can effectively isolate groundwater and reduce the water level in the soft soil foundation, thereby reducing the situation of foundation consolidation sinking caused by the reduction of groundwater, and improving the stability of the foundation; during construction, the top surface elevation and slope of the cushion layer need to be accurately controlled to provide a flat foundation for the subsequent continuous reinforced concrete slab 4 construction.

[0053] Further optimization scheme, in the process of filling a layer of gravel cushion 3 on the upper layer of the civil grid 2, the gravel cushion 3 is layered and each layer is compacted and leveled. The gravel cushion 3 is constructed in layers, and each layer needs to be compacted and tamped to ensure the strength of the gravel cushion 3 and effectively prevent the gravel cushion 3 from spreading out.

[0054] In an embodiment of the present application, the gravel cushion 3 is the basic and core functional layer of the method, and reinforcing materials are added below and above the gravel cushion 3, the civil grid 2 of civil synthetic material below, and the continuous reinforced concrete slab 4 above, which greatly improves the bearing capacity and integrity of the cushion.

[0055] In one embodiment of the present application, the reinforced sand cushion is a composite structure composed of the geogrid 2 and the sand cushion 3. The geogrid 2 is evenly laid on the subgrade, and the high tensile strength and low strain characteristics of the geogrid are used to limit the load deformation of the soft soil subgrade. The sand cushion 3 is continuously laid on the surface of the geogrid 2 to form a reinforced composite structure. This structure can effectively disperse and uniformly transfer the dead weight and vehicle load from the upper structure, thereby improving the load stability and overall stiffness of the soft soil subgrade.

[0056] Further optimization, the process of pouring a layer of continuous reinforced concrete slab 4 on the surface of the sand cushion 3 also includes the following steps: supporting the side formwork 7 on the sand cushion 3, the size of the side formwork 7 is matched with the continuous reinforced concrete slab 4; binding the steel reinforcement 8 in both directions inside the side formwork 7 as the framework of the continuous reinforced concrete slab 4; pouring concrete into the side formwork 7, vibrating and compacting and smoothing the surface; curing the concrete to harden the concrete to form the continuous reinforced concrete slab 4; after the concrete hardness reaches the standard, the side formwork 7 is removed. After the sand cushion 3 is compacted, the side formwork 7 is supported according to the design size and elevation, the formwork is about 8-10 cm high, the steel reinforcement is bound and the double-layer steel mesh is laid to form the steel reinforcement 8, and C20 or above commercial concrete is poured, paying attention to vibration and compaction to avoid segregation, honeycomb and rough surface; the continuous reinforced concrete slab 4 is cured according to the specification for not less than 7 days to ensure that the strength of the concrete can meet the design requirements; the combination of the continuous reinforced concrete slab 4 with the geogrid 2 and the sand cushion 3 floating on the soft soil can better improve the bearing capacity of the soft soil subgrade, and is suitable for the soft soil layer 1 in the Dongting Lake area in highway engineering.

[0057] Further optimization, the process of pouring a layer of continuous reinforced concrete slab 4 on the surface of the sand cushion 3 also includes the following steps: the continuous reinforced concrete slab 4 is continuously poured to form a whole. When the area of the continuous reinforced concrete slab 4 is large, the deformation caused by temperature change is small due to the large depth of the reinforced concrete, and it is not easy to be damaged due to thermal expansion and contraction, and it is best to be poured at one time.

[0058] In one embodiment of the present application, the surface layer 6 is selected from conventional pavement materials, including but not limited to asphalt concrete, to facilitate pedestrian and vehicle traffic on the pavement.

[0059] Further optimization, the thickness of the continuous reinforced concrete slab 4 is 8-10 cm.

[0060] Further optimization, in the process of laying a layer of base layer 5 on the top end of the continuous reinforced concrete slab 4, the thickness of the base layer 5 is 30-50 cm.

[0061] Specific examples:

[0062] For the deep soft soil and special soil layer of Dongting Lake area, firstly, the civil grid 2 is used to diffuse stress, and then a layer of gravel cushion 3 is laid to isolate the unstable soft soil layer 1, prevent the deformation shrinkage of the soft soil, reduce the permeability of the foundation, and heat and water for the soft soil layer 1; a layer of 8-10cm continuous reinforced concrete slab 4 is poured on the gravel cushion 3 to improve the bearing capacity and reduce uneven deformation. The difficulty of the scheme lies in that the soft soil layer 1 is flattened, the deformation modulus is basically consistent, the gravel cushion 3 is uniformly laid, the gravel cushion 3 is layered and compacted and flattened, the water in the lower soft soil layer cannot be permeated upward, the double-layer continuous reinforced concrete slab 4 is continuous and unbroken in the treatment section, and the stress and deformation are uniform and meet the requirements.

[0063] In the description of the present application, it should be understood that the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0064] The above-described embodiments are only preferred modes of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope of the present application.

Claims

1. A method for treating a deep soft ground uneven settlement ground foundation, characterized by, The method comprises the following steps: exploring the soft soil distribution and groundwater conditions of the foundation site, and then treating the soft soil layer (1); setting a layer of civil grid (2) on the treated soft soil layer (1) to isolate and block the soft soil; filling a layer of gravel cushion (3) on the civil grid (2), and leveling and compacting the gravel cushion (3); pouring a layer of continuous reinforced concrete slab (4) on the surface of the gravel cushion (3), and curing the concrete slab; after the continuous reinforced concrete slab (4) reaches the design strength, laying a layer of base layer (5) on the top of the continuous reinforced concrete slab (4), and leveling and compacting; leveling the top surface of the base layer (5), and then laying a layer of surface layer (6) on the top of the base layer (5) as the pavement for walking on the road.

2. The deep soft ground foundation differential settlement foundation treatment method according to claim 1, characterized by, The process of treating the selected foundation site comprises the following steps: removing sundries on the surface of the selected foundation site; excavating the planting soil above the soft soil layer (1) to expose the soft soil foundation; leveling and compacting the exposed soft soil foundation using engineering machinery.

3. The deep soft ground foundation differential settlement foundation treatment method according to claim 2, characterized by, The process of treating the selected foundation site further comprises the following steps: analyzing the groundwater and precipitation conditions of the soft soil foundation site; building a temporary drainage ditch on the soft soil foundation.

4. The method for treating a deep soft ground uneven settlement ground according to claim 1, characterized by: In the process of setting a layer of civil grid (2) on the treated foundation, the adjacent civil grids (2) are connected by overlapping.

5. The method for treating a deep soft ground uneven settlement ground according to claim 1, wherein: In the process of filling a layer of gravel cushion (3) on the top of the civil grid (2), the height of the gravel cushion (3) is 0.5-1m.

6. The method of claim 1, wherein: In the process of filling a layer of gravel cushion (3) on the top of the civil grid (2), the gravel cushion (3) is laid in layers, and each layer is compacted and leveled.

7. The method for treating a deep soft ground foundation uneven settlement foundation according to Claim 1, wherein The process of pouring a layer of continuous reinforced concrete slab (4) on the surface of the gravel cushion (3) further comprises the following steps: supporting side formwork (7) on the gravel cushion (3), and the size of the side formwork (7) is matched with the continuous reinforced concrete slab (4); binding steel reinforcement framework (8) in both directions inside the side formwork (7) as the framework of the continuous reinforced concrete slab (4); pouring concrete into the side formwork (7), vibrating and compacting, and troweling the surface; curing the concrete to harden and form the continuous reinforced concrete slab (4); after the hardness of the concrete meets the standard, removing the side formwork (7).

8. The deep soft ground foundation differential settlement foundation treatment method according to claim 7, characterized by, The process of pouring a layer of continuous reinforced concrete slab (4) on the surface of the gravel cushion (3) further comprises the following steps: pouring the continuous reinforced concrete slab (4) continuously to form a whole.

9. The method of claim 7, wherein: The thickness of the continuous reinforced concrete slab (4) is 8-10cm.

10. The method of claim 1, wherein: In the process of laying a layer of base layer (5) on the top of the continuous reinforced concrete slab (4), the thickness of the base layer (5) is 30-50cm.

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