Round raft foundation under non-uniform geological condition

Abstract

The utility model discloses a circular raft foundation under uneven geological conditions, and belongs to the technical field of engineering structure foundations. The foundation adopts an annular reinforced concrete structure, geological differences are eliminated through concrete foundation replacement, a modified emulsified asphalt layer and an asphalt felt sliding layer are arranged on a concrete cushion layer to form a composite sliding layer, and the foundation constraining force is effectively reduced. Initiating seams with rubber water-stop belts are arranged on the circumference of the raft foundation, and the double functions of stress release and water prevention are achieved in cooperation with filling agents. The surface of the structure is coated with an epoxy resin anti-corrosion coating to enhance durability, stress generated by differential settlement and temperature deformation of the foundation can be absorbed through the synergistic effect of the sliding layer and the deformation joint, and the anti-cracking performance of the structure is remarkably improved. Compared with a traditional foundation, the foundation has the advantages of being convenient to construct, high in deformation adaptability, low in maintenance cost and the like, is suitable for foundation construction of large facilities such as sewage treatment plants under complex geological conditions, and has remarkable economic benefits and engineering application value.

Description

TECHNICAL FIELD

[0001] The utility model relates to engineering structure foundation technical field, especially under the uneven geological condition round raft foundation. BACKGROUND

[0002] With the demand of sewage treatment more and more, large sewage treatment plant becomes one of the key livelihood projects, and the complexity of geological conditions poses a severe challenge to the safety and stability of buildings. Restricted by the region of engineering construction, it has become a common phenomenon to carry out large infrastructure construction under uneven geological conditions, and how to ensure the safety and stability of the structure under uneven geological conditions and to carry out construction quickly has become the top priority of building structure foundation design and construction.

[0003] Affected by geological structure, stratum distribution and underground water and other environments, uneven stratum structure is prone to occur in engineering construction area, and this geological structure is easy to cause insufficient bearing capacity of foundation and uneven settlement of foundation, which greatly tests the stability, safety and anti-deformation cracking capacity of buildings. UTILITY MODEL CONTENT

[0004] To solve the above problems, the utility model provides a round raft foundation under uneven geological conditions, which reduces the foundation restraint force, releases the internal stress of the structure, meets the needs of structural deformation, and can adapt to the deformation of the foundation or the thermal expansion and contraction deformation of the concrete member caused by temperature. The structure concrete can resist deformation and cracking, the probability of structure cracking in the later period is reduced, the defect treatment cost is saved, and good economic and social benefits are generated.

[0005] The utility model adopts the technical scheme that:

[0006] A round raft foundation under uneven geological conditions, the whole round raft foundation is annular, adopts a reinforced concrete foundation structure, and is provided with an oil felt sliding layer between the reinforced concrete foundation structure and the concrete foundation. The round raft foundation is provided with concentric circular trigger joints and a plurality of circumferential trigger joints.

[0007] Further, the uneven geological conditions are treated by replacing the concrete foundation, and a concrete cushion layer is poured on the concrete foundation after the replacement treatment.

[0008] Further, the concrete cushion layer is coated with a modified emulsified asphalt layer, and the concrete foundation is bonded with the oil felt sliding layer through the modified emulsified asphalt layer.

[0009] Further, the oil felt sliding layer is a layer of petroleum asphalt paper tire oil felt sequentially laid from one side to the other side.

[0010] Further, the round raft foundation is provided with a rubber waterstop at the position of the trigger joint.

[0011] Further, the upper surface of the circular raft foundation is coated with an epoxy resin anticorrosive coating.

[0012] Further, the initiation slit is filled with a filler after being cleaned.

[0013] The raft foundation has the advantages that:

[0014] 1. Strong stress release and deformation adaptability:

[0015] The composite sliding interface formed by the linoleum sliding layer and the modified emulsified asphalt layer effectively reduces the frictional restraint of the foundation on the foundation, releases the internal stress of the structure; the initiation slit arranged in the circumference cooperates with the rubber waterstop to allow the raft to produce controllable deformation when the temperature changes or the foundation settles, avoid concrete cracking caused by stress concentration, and improve the structure cracking performance.

[0016] 2. Geological adaptability and bearing capacity optimization:

[0017] The uneven geology is treated by replacement combined with a concrete cushion to improve the bearing capacity difference of the foundation; the circular ring structure design enhances the overall stiffness, and forms a "rigid and flexible" system with the sliding layer, which can not only disperse load stress, but also adapt to local foundation deformation, significantly improving the stability of the foundation.

[0018] 3. Waterproofing, corrosion protection and durability improvement

[0019] The rubber waterstop and filler in the initiation slit realize the sealing and waterproofing of the deformation joint, and the surface epoxy resin coating enhances the anti-permeation and corrosion resistance, thereby greatly prolonging the service life of the foundation, reducing the damage risk of groundwater erosion and environmental factors on the concrete.

[0020] 4. Economic efficiency and construction convenience

[0021] By actively releasing stress and optimizing crack control, the cost of later crack repair is reduced; the standardized construction process (such as layered linoleum paving, slit cutting and filling, etc.) simplifies the construction process, shortens the construction period, and is suitable for the rapid construction needs of large projects such as sewage treatment plants under complex geological conditions. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a plan view of the circular raft foundation of the utility model;

[0023] Figure 2 is a structural view of the linoleum sliding layer of the utility model;

[0024] Figure 3 is a structural view of the initiation slit of the utility model;

[0025] In the figure: 1, round raft foundation; 2, initiation joint; 3, linoleum sliding layer; 4, rubber waterstop; 5, filling agent; 6, upper layer of steel bars; 7, epoxy resin anticorrosive coating. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings of the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative effort fall within the scope of protection of the utility model.

[0027] In view of the fact that engineering construction areas are prone to uneven stratum structure under the influence of geological structure, stratum distribution and underground water and the like, which causes insufficient bearing capacity of the foundation and uneven settlement of the foundation, and affects the stability, safety and deformation resistance and cracking of the building, the embodiment provides a round raft foundation under uneven geological conditions.

[0028] As shown in Figure 1 , the round raft foundation 1 is in the shape of a whole ring, and is of a reinforced concrete foundation structure, and the round raft foundation is provided with a concentric round initiation joint 2 and a plurality of circumferential initiation joints 2. As shown in Figure 2 , the round raft foundation 1 is provided with a linoleum sliding layer 3 between the round raft foundation 1 and the concrete foundation. The linoleum sliding layer 3 can reduce the friction between the round raft foundation 1 and the concrete foundation, significantly reduce the restraint force of the foundation, and release the stress caused by temperature and settlement. The initiation joints 2 are circumferentially arranged and extend radially towards the center of the round raft foundation 1. When the initiation joints 2 produce stress in the concrete foundation, they can form a multi-directional stress release path, reduce crack concentration, and meet the waterproofing requirement. In this way, the bearing capacity of the structure concrete and the foundation is ensured, the anti-seepage and anti-cracking performance of the concrete is effectively improved, and the occurrence rate of cracks in the concrete structure is reduced.

[0029] The specific construction process of the round raft foundation 1 is as follows:

[0030] In view of the uneven geological conditions of the concrete foundation, the uneven geological conditions are treated by replacement, and a concrete cushion layer is cast on the foundation after the replacement treatment. The concrete cushion layer helps to level the concrete foundation, provides a stable base surface for the sliding layer and the initiation joint 2 system, and also realizes multiple functions such as load uniformity, moisture-proof isolation and construction support.

[0031] After the strength of the cushion concrete layer meets the design requirements, the oil felt sliding layer 3 is constructed. First, the surface of the cushion layer is cleaned to ensure that the contact surface is dry and clean. A layer of modified emulsified asphalt is applied to the surface of the cushion layer to increase the bonding strength of the oil felt sliding layer 3 and the concrete cushion layer. After the application is completed, a layer of 1.5mm thick petroleum asphalt paper felt is laid from one side to the other. The specifications are 350mm. To ensure the quality of the laying, the laying should be flat and without wrinkles. The overlap width of the same layer is 500mm, and the overlap width of the upper and lower layers is 80mm. The 1.5mm petroleum asphalt paper felt is used as the sliding layer to reduce the friction between the circular raft foundation 1 and the concrete cushion layer, significantly reduce the restraint force of the circular raft foundation 1, and release the stress caused by temperature and settlement. The modified emulsified asphalt layer enhances the interlayer bonding to ensure the stability of the sliding layer.

[0032] Secondly, after the oil felt sliding layer 3 is laid, the foundation steel of the circular raft foundation 1 is made and installed. The circular raft foundation 1 has a diameter of 50m and a thickness of 0.8m. The compressive strength grade of the foundation material is C30, the waterproof grade is P6, and the crack control grade is three. The foundation steel is HRB400E anti-seismic steel, and a double-layer and double-direction reinforcement method is used. The foundation steel is uniformly made and formed in the steel processing plant and transported to the construction site for installation. To prevent damage to the oil felt sliding layer 3 during the installation of the foundation steel, protective treatment is carried out on the oil felt sliding layer 3 during the construction process. When the foundation steel is hoisted, the lower side is supported by wooden blocks to prevent damage to the oil felt sliding layer 3. When the foundation steel and the circular raft foundation 1 are installed, according to the structural stress characteristics, six initiation joints 2 are set on the circular raft foundation 1 during the installation process. One of them is arranged concentrically at a distance of 15.5m from the center, and the remaining five are arranged circumferentially on the circular raft foundation 1. The initiation joint 2 is in the form of a false joint, which is a kind of incomplete cut-off concrete structure joint. It forms a local stress concentration point by pre-setting a groove, notch or weakened area on the surface or inside of the concrete, so that the structure cracks preferentially at this point when stressed or deformed, thereby controlling the position and direction of the crack. To prevent uneven settlement from causing foundation deformation and cracking, which affects the waterproof performance of the structure, a CB350*8-30 rubber waterstop 4 is provided at the middle position of the initiation joint 2 on the circular raft foundation 1. To prevent rusting of the upper layer of steel 6 on the circular raft foundation 1, which affects the safety of the structure, an epoxy resin anticorrosive coating 7 is applied to the upper surface of the circular raft foundation 1 to improve the corrosion resistance of the structural steel.

[0033] Finally, the concrete pouring of the circular raft foundation 1 is carried out, in order to improve the concrete pouring quality of the circular raft foundation 1, prevent quality defects such as honeycomb, pitted surface, cavity, crack and the like, 2 50m pumps are equipped at the operation site for continuous pouring, at the same time, the pouring surface is covered and watered for maintenance immediately after the pouring is completed, so as to reduce the internal and external temperature difference caused by the hydration heat of the concrete, and reduce the probability of temperature cracks. After the concrete maintenance meets the design requirements, the cutting joint 2 position is cut and cleaned, the joint width is 3cm, and the depth is 4cm, and after the cleaning is completed, the joint 2 position is filled with the filling agent 5, and the filling agent 5 is polythiourethane sealant, so as to improve the anti-permeability of the cutting joint 2. The cutting joint 2 layout combined with the radial and the circumferential is combined with the rubber waterstop 4, so as to balance the stress release and the waterproof demand; the false joint is designed to be filled with polythiourethane sealant, so as to consider the deformation adaptability and the anti-permeability.

[0034] In summary, the circular raft foundation 1 sets the oil felt sliding layer 3 between the foundation and the cushion, sets the cutting joint 2 on the foundation, under the premise of meeting the structural safety and stability, in a simple, economical and convenient construction manner, effectively reduces the restraint of the foundation on the circular raft foundation 1, releases the internal stress of the structure, meets the structural deformation needs, at the same time, can adapt to the deformation of the foundation or the thermal expansion and cold contraction deformation of the concrete member caused by the temperature change, effectively improves the deformation and crack resistance of the circular raft foundation 1 under the uneven geological conditions, greatly reduces the shrinkage crack occurrence rate of the circular raft foundation 1, reduces the resource investment of the later crack treatment, saves the defect treatment cost, at the same time, effectively improves the anti-permeability and crack resistance of the structure, improves the service life and safety performance of the structure to a certain extent, and good social and economic benefits are generated.

[0035] The basic principle, main features and advantages of the utility model are shown and described above. It should be understood by those skilled in the art that the utility model is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principle of the utility model, and various changes and improvements can be made to the utility model without departing from the spirit and scope of the utility model, and these changes and improvements all fall within the scope of the utility model claimed. The scope of protection of the utility model is defined by the appended claims and their equivalents.

Claims

1. A circular raft foundation in non-uniform geological conditions, characterised in that: The circular raft foundation is in the shape of a whole ring, adopts a reinforced concrete foundation structure, is provided with an oil felt sliding layer between the reinforced concrete foundation structure and the concrete foundation, and is provided with concentric circular initiation joints and a plurality of circumferential initiation joints.

2. The circular raft foundation under non-uniform geologic conditions of claim 1, wherein: The concrete foundation is subjected to replacement treatment at uneven geological positions, and a concrete cushion layer is poured on the concrete foundation after the replacement treatment is completed.

3. The circular raft foundation under non-uniform geologic conditions of claim 2, wherein: The concrete cushion layer is coated with a modified emulsified asphalt layer, and the concrete foundation is bonded with the oil felt sliding layer through the modified emulsified asphalt layer.

4. The circular raft foundation under non-uniform geologic conditions of claim 1, wherein: The oil felt sliding layer is a layer of petroleum asphalt paper felt that is sequentially laid from one side to the other side.

5. The circular raft foundation under non-uniform geologic conditions of claim 1, wherein: The circular raft foundation is provided with a rubber waterstop at the position of the initiation joints.

6. The circular raft foundation under non-uniform geologic conditions of claim 1, wherein: The upper surface of the circular raft foundation is coated with an epoxy resin anticorrosive coating.

7. The circular raft foundation under non-homogeneous geological conditions as claimed in claim 1 wherein: The initiation joints are filled with a filling agent after being cut and cleaned.

Images