A manhole perimeter backfill structure based on fluidized solidified soil casting

Abstract

This invention provides a backfill structure for manholes based on fluidized solidified soil casting. The structure includes the manhole body, a concrete cushion layer, a polyurethane waterproof coating, a ring-shaped waterstop steel plate, a fluidized solidified soil backfill layer, elastic sealant, and reinforcing components. Through multiple waterproofing designs and layered casting of self-compacting fluidized solidified soil, including the polyurethane coating, waterstop steel plate, and sealant, it solves the problems of insufficient compaction, easy leakage, and long construction period associated with traditional backfilling methods. Actual measurement data shows that this structure achieves a backfill density of ≥96% and shortens the construction period by 83%. It is suitable for municipal manhole projects, especially in areas with high groundwater levels and settlement sensitivity.

Description

Technical Field

[0001] This utility model belongs to the field of manhole perimeter technology, and in particular relates to a manhole perimeter backfill structure based on fluidized solidified soil casting. Background Technology

[0002] In municipal engineering, manholes are crucial nodes for underground pipelines, and the quality of the backfill around them directly affects road stability and pipeline safety. Traditional backfilling methods often involve layering and compacting plain soil or lime-soil, which presents the following problems:

[0003] (1) Compaction quality defects: The space around the manhole is narrow, making mechanical compaction difficult and failing to achieve the compaction degree required by specifications, which is usually required to be ≥95%. The actual measured compaction degree is often lower than 85%, resulting in uneven road settlement. The average annual settlement can reach 3-5 cm, which easily leads to road defects such as voids or settlement. Patent CN202111216551.8 discloses a construction method for fluidized solidified soil, but it does not optimize for the special structure around the manhole.

[0004] (2) Insufficient waterproofing performance: Conventional backfill materials have a high permeability coefficient, with plain soil k≥1×105cm / s. Groundwater can easily seep in through the gaps around the well, causing the inspection well to float or the structure to corrode. Long-term water erosion can lead to structural failure. Existing patent CN202321264263.4 proposes a support device to assist in pouring, but it does not solve the problem of interface waterproofing.

[0005] (3) Low construction efficiency. Traditional methods require layered filling and layered testing, resulting in a long construction cycle for a single well and the need for multiple mechanical visits, leading to high costs.

[0006] (4) Limitations of fluidized solidified soil. Fluidized solidified soil has advantages such as self-compacting, good fluidity, and adjustable strength, but its application around manholes requires addressing issues such as pouring stability, waterproofing, and bonding with the manhole wall.

[0007] In summary, there is currently no dedicated backfill structure design for the periphery of inspection wells in the existing technology. Utility Model Content

[0008] In view of this, the purpose of this utility model is to solve the problems of compaction difficulties, easy settlement, and poor impermeability of traditional backfilling methods.

[0009] In the first aspect, this utility model embodiment provides a manhole perimeter backfill structure based on fluidized solidified soil casting, including manhole body, concrete cushion layer, polyurethane waterproof coating, annular waterstop steel plate, fluidized solidified soil backfill layer, elastic sealant, and reinforcing components.

[0010] The concrete cushion layer is filled on the surface of the construction trench. The manhole body and the fluidized solidified soil backfill layer are installed on the surface of the concrete cushion layer. The polyurethane waterproof coating is filled between the outer wall of the manhole body and the fluidized solidified soil backfill layer. The elastic sealant is filled between the polyurethane waterproof coating and the fluidized solidified soil backfill layer. An annular water-stop steel plate that mechanically interlocks with the fluidized solidified soil backfill layer is pre-embedded in the middle of the manhole wall. The fluidized solidified soil backfill layer is constructed by layering fluidized solidified soil, and reinforcing components are embedded in the fluidized solidified soil backfill layer.

[0011] It also includes template components, which are detachable steel templates and are fixed by diagonal bracing with diagonal bracing on the outside with a spacing of ≤1.5m.

[0012] The present invention provides the following beneficial effects:

[0013] This invention improves construction efficiency and structural durability by utilizing the self-compacting properties of fluidized solidified soil to ensure a backfill compaction degree of ≥98% around the well; through multiple waterproof designs, the permeability coefficient is reduced to ≤1×10cm / s; and the construction cycle for a single well is shortened to within 24 hours, reducing the use of machinery. Specifically:

[0014] Highly efficient construction: The fluidized solidified soil is self-leveling and requires no vibration, shortening the construction period by more than 50%;

[0015] Structural stability: Layered casting combined with reinforced structure improves anti-settlement performance by 30%;

[0016] Waterproof and seepage-proof: Multiple waterproof designs effectively prevent groundwater seepage;

[0017] Environmental economy: using local materials to reduce the transportation of waste soil and material waste.

[0018] Other features and advantages of this invention will be set forth in the following description, and some features will become apparent from the description or may be learned by practicing the invention. The objectives and other advantages of this invention are realized and obtained through the structures particularly pointed out in the description, claims, and drawings.

[0019] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0020] Figure 1 A cross-sectional view of the backfill structure around the manhole provided in an embodiment of this utility model.

[0021] Illustration: 1-Manhole body; 2-Concrete pad; 3-Polyurethane waterproof coating; 4-Annular waterstop steel plate; 5-Flowable solidified soil backfill layer; 6-Elastic sealant; 7-Reinforcing components; 8-Formwork components. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] To facilitate understanding of this embodiment, a detailed description of a manhole perimeter backfill structure based on fluidized solidified soil pouring disclosed in this utility model embodiment will be provided first, including the manhole body 1, concrete cushion layer 2, polyurethane waterproof coating 3, annular waterstop steel plate 4, fluidized solidified soil backfill layer 5, elastic sealant 6, reinforcing components 7, and template components 8.

[0024] A concrete cushion layer 2 is filled on the surface of the construction trench. The manhole body 1 and the fluidized solidified soil backfill layer 5 are installed on the surface of the concrete cushion layer 2. A polyurethane waterproof coating 3 is filled between the outer side of the manhole body 1 and the fluidized solidified soil backfill layer 5. An elastic sealant 6 is filled between the polyurethane waterproof coating 3 and the fluidized solidified soil backfill layer 5. An annular water-stop steel plate 4, which forms a mechanical interlock with the fluidized solidified soil backfill layer 5, is pre-embedded in the middle of the manhole wall. Specifically, the annular water-stop steel plate 4 is centered along the height direction of the manhole body 1. The inner edge is fixed to the manhole wall concrete by welding through pre-embedded parts, and the outer edge extends towards the fluidized solidified soil backfill layer 5, with the extended part completely embedded in the fluidized solidified soil backfill layer 5, forming a mechanical interlocking structure with the fluidized solidified soil. Furthermore, the thickness of the concrete cushion layer 2 is ≥150mm and the grade is C20; the thickness of the polyurethane waterproof coating 3 is ≥150mm; the thickness of the waterstop steel plate 4 is ≥3mm, the width is ≥150mm, and the anchoring depth into the well wall is ≥100mm; the elastic sealant 6 is a polysulfide sealant with a Shore hardness ≥50A.

[0025] The fluidized solidified soil backfill layer 5 is constructed by layering fluidized solidified soil with a slump of 180-220mm, and reinforcing components 7 are embedded in the fluidized solidified soil backfill layer 5. The reinforcing components 7 can be steel cages or fiber mesh. The steel cages are made of HPB300 material with a specification of 8mm@200mm, and the fiber mesh is 300g / m². 2 Polypropylene fiber mesh.

[0026] Template component 8 uses detachable steel templates and is fixed by diagonal bracing. Diagonal bracing is provided on the outside with a spacing of ≤1.5m.

[0027] The construction method of the manhole perimeter backfill structure based on the pouring of fluidized solidified soil according to this utility model is as follows: Please refer to [link / reference]. Figure 1 The specific implementation steps include:

[0028] (1) Foundation treatment: mechanically excavate to the design elevation, manually clean up the loose soil, and pour C20 concrete cushion layer 2 with flatness ≤3mm / m and thickness ≥150mm.

[0029] (2) Well wall pretreatment: Spray a 2mm thick polyurethane waterproof coating and a 3mm thick polysulfide sealant on the outside of the inspection well body 1. The polyurethane waterproof coating can be GB / T19250-2013 Type II; and embed an annular water-stop steel plate in the well wall.

[0030] (3) Formwork erection: Demountable steel formwork is used, with a height of 1.5m / section. Diagonal bracing is provided on the outside with a spacing of ≤1.5m and the formwork assembly error is ≤2mm.

[0031] (4) Layered pouring: The first layer is a 0.5m high fluidized solidified soil layer, which is left to stand for 4 hours before inserting a reinforcing cage or polypropylene fiber mesh; each subsequent layer is poured with an interface agent applied before pouring, the cement:water ratio is 1:0.4, and the pouring interval is ≥12 hours; a pumping process is used, and the pouring speed is controlled at 2m / s. 3 / h, to avoid impact damage to the template.

[0032] The thickness of each layer is ≤1.5m, preferably 1.2m; the solidified soil formula (by mass) is: 100 parts soil, 12-15 parts P.O42.5 cement, 6-8 parts curing agent (mainly AlO-SiO-CaO), and 25-30 parts water; the 28-day unconfined compressive strength is ≥1.2MPa, and the permeability coefficient is ≤1×10cm / s.

[0033] (5) Maintenance and testing: Cover with film to keep moist for 7 days, during which the temperature is monitored to be ≥5℃; test the density of the backfill layer.

[0034] It should be noted that, in this document, the terms “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0035] Although embodiments of the present 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 present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A manhole peripheral backfill structure based on fluidized solidified soil pouring, characterized in that, This includes the manhole body, concrete cushion layer, polyurethane waterproof coating, annular waterstop steel plate, fluidized solidified soil backfill layer, elastic sealant, and reinforcement components. The concrete cushion layer is filled on the surface of the construction trench. The manhole body and the fluidized solidified soil backfill layer are installed on the surface of the concrete cushion layer. The polyurethane waterproof coating is filled between the outer side of the manhole body and the fluidized solidified soil backfill layer. The elastic sealant is filled between the polyurethane waterproof coating and the fluidized solidified soil backfill layer. The annular water-stop steel plate that forms a mechanical interlock with the fluidized solidified soil backfill layer is pre-embedded in the middle of the manhole wall.

2. The inspection well perimeter backfill structure of claim 1, wherein, It also includes template components, which are detachable steel templates and are fixed by diagonal bracing with diagonal bracing on the outside with a spacing of ≤1.5m.

3. The inspection well perimeter backfill structure of claim 1, wherein, The fluidized solidified soil backfill layer is constructed by layering fluidized solidified soil and embedding reinforcing components within the fluidized solidified soil backfill layer.

4. The backfill structure around the inspection well according to claim 3, characterized in that, The reinforcing component is a steel cage or fiber mesh.

5. The backfill structure around the inspection well according to claim 1, characterized in that, The concrete cushion layer is graded C20 and has a thickness of ≥150mm.

6. The backfill structure around the inspection well according to claim 2, characterized in that, The thickness of the polyurethane waterproof coating is ≥150mm; the thickness of the waterstop steel plate is ≥3mm, the width is ≥150mm, and the anchoring depth into the well wall is ≥100mm; the elastic sealant is polysulfide sealant with a Shore hardness ≥50A.

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