An integrated construction method of a seepage-proofing and heat-insulating layer of an underground silo structure

Abstract

The present application relates to the technical field of underground space structure construction, in particular to a kind of anti-seepage and heat preservation layer integrated construction method of underground silo structure.The present application constructs the continuous cavity between underground silo structure and surrounding floor, side wall, then fully utilizes the material properties of non-water reaction retarding solidification type expanding polymer material, multi-point synchronous grouting, material expansion filling, extrusion continuous cavity, and realizes the close combination between underground silo structure outer wall and backfill, to realize the anti-seepage and heat preservation layer integrated construction.The present application effectively avoids the leakage and heat preservation failure caused by material lap, backfill damage and other safety problems in the construction of traditional underground structure waterproofing and insulation layer, significantly improves the overall waterproofing, insulation performance and long-term operation safety and reliability of underground silo structure.

Description

Technical Field

[0001] This invention belongs to the field of underground space structure construction technology, specifically relating to an integrated construction method for the seepage prevention and insulation layer of an underground silo structure. Background Technology

[0002] Underground silo structures, with their excellent load-bearing performance and space utilization, combined with the relatively constant shallow geothermal temperature, have been widely used in infrastructure fields such as crude oil reserves, grain storage, water conservancy and water storage, and municipal drainage. However, during long-term operation, they face two major threats: First, groundwater leakage, especially in silos located in areas with complex hydrogeological conditions, where they are subjected to high hydrostatic pressure and dynamic water pressure fluctuations over a long period, which can easily lead to structural leakage, causing the internal media to become damp, corroded, or malfunction. Second, the impact of temperature changes in the surrounding soil, especially in southern my country, where high underground temperatures can still cause the internal stored media to deteriorate, affecting the storage period and requiring long-term cooling measures, thus affecting overall operational energy consumption.

[0003] To address the aforementioned issues, traditional underground silo seepage prevention designs primarily rely on two lines of defense: first, the structural body itself, employing waterproof concrete (such as P8 or P10 grade) and admixtures to achieve self-waterproofing, utilizing the concrete's density and hydrophobic capillary structure to block water penetration; second, an additional flexible waterproof layer, typically polymer-modified bitumen membranes, polyurethane coatings, or polymer self-adhesive films, applied to the water-facing side of the structure to form a continuous barrier to compensate for inherent concrete defects (such as expansion joints, temperature stress joints, honeycombing, and construction joints). However, due to limitations in construction techniques, flexible waterproof layers inevitably have weak points such as overlapping joints, corner sealing, and backfill layer settlement tears. Quality control in these areas heavily depends on the substrate treatment, environmental temperature and humidity, and the skill level of the construction workers, making them highly susceptible to becoming leakage channels under actual service conditions. Investigations have found that over 80% of leakage incidents in underground engineering stem from the failure of waterproof layer overlaps or joint treatment.

[0004] Meanwhile, to reduce the impact of temperature changes on the internal environment of underground spaces, especially to prevent condensation on the inner walls, the conventional practice is to lay an insulation layer on the outside of the waterproof layer of the outer walls. Commonly used materials include extruded polystyrene (XPS), molded polystyrene (EPS), or rigid polyurethane foam. During construction, the insulation boards are usually laid in layers with staggered joints and fixed with adhesive mortar or anchors. However, layered laying inevitably creates a large number of cold joints between the boards. These cold joints not only weaken the continuity of the insulation layer, creating a thermal bridging effect and reducing the overall insulation effect, but more importantly, during the backfilling process, the backfill soil contains large-diameter hard foreign objects, and improper mechanical compaction and vibration can cause uneven compression and scratches on the insulation boards, leading to cracking, displacement, or even breakage of the boards. Even with high-strength insulation boards, it is difficult to completely avoid mechanical damage during the backfilling process. Actual engineering surveys have revealed that after backfilling, the breakage rate of insulation boards often reaches 15% to 30%, and the insulation performance in some areas drops by more than 50%, severely weakening the designed insulation capacity and falling far short of the expected results.

[0005] Further analysis revealed that in current technical solutions, the concrete self-waterproofing layer, flexible waterproofing layer, and insulation layer are typically constructed in separate, layered steps. Specifically, the main underground structure is first formed by casting concrete and then curing it before the flexible waterproofing layer and insulation layer are sequentially applied to its outer surface. Each layer has a different function, is completed by different labor teams at different times, and lacks integrated system planning and coordinated design and construction, resulting in significant functional coupling issues. For example, the flexible waterproofing layer requires a smooth, dry, and clean base surface, while the insulation layer often requires a rough surface or one with anchor points; these requirements contradict each other. If measures are taken, such as anchors used to fix the insulation board, penetrating the waterproofing layer will compromise its integrity, creating new leakage channels. If a pure bonding method is used to avoid penetration, it cannot withstand the tensile force of post-construction settlement of the backfill soil, leading to cracking of the flexible waterproofing layer. In addition, multi-layer construction has accumulated problems such as intermittent work processes, pollution from cross-operations, and difficulties in the acceptance of concealed works, making it extremely difficult to control the overall construction quality. Failure of any layer may lead to the imbalance of the entire system and make it difficult to achieve the expected results.

[0006] In summary, the current technical system relying on "structural self-waterproofing + flexible waterproofing layer + layered insulation board" suffers from several drawbacks. Independent construction of each layer, poor material compatibility, weak interrelationship of structural details, and susceptibility to backfill damage all contribute to the challenges. Underground structures, especially underground silos, face higher requirements for seepage prevention and insulation. Insufficient stability and durability of waterproofing and insulation quality lead to frequent leaks and insulation degradation during operation, resulting in high maintenance costs and severely impacting the structural lifespan. Therefore, there is an urgent need to develop a new construction method that integrates seepage prevention and insulation, enabling coordinated action and reliable construction quality, to fundamentally solve these technical challenges. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide an integrated construction method for the seepage prevention and insulation layer of underground silo structures.

[0008] This invention is achieved through the following technical solution: A method for integrated construction of the seepage-proof and thermal insulation layer of an underground silo structure includes the following steps: S1: Level the foundation (1) and construct the concrete cushion layer (2). S2: Measure and lay out the lines, and draw the plane range marking lines (4) of the underground silo structure (3) on the surface of the concrete cushion layer (2). S3: Place a pad (6) made of non-aqueous reaction slow-curing expansion polymer material (5) within the plane range marking line (4), and precisely control the elevation of the pad (6) by means of a laser level and a triangular steel pad (9); S4: The steel formwork (10) is hoisted as a whole and precisely installed on the pad (6) according to the plane range marking line (4); S5: Pre-embed grouting pipes (11) evenly around the plane range marking line (4). The grout outlet at the lower end of the grouting pipe (11) is located in the cavity between the lower part of the steel formwork (10) and the concrete cushion layer (2), and the grout inlet at the upper end extends to the elevation above the inlet (13). S6: Construct the bottom slab (7), side walls (8), top slab (12) and entrance (13) of the underground silo structure (3) in sequence. S7: A secondary retaining structure (17) consisting of circumferential steel bars (14), vertical steel bars (15) and geotextile (16) is set on the outside of the side wall (8) of the underground silo structure (3), and fluidized solidified soil (19) is backfilled between the outside of the secondary retaining structure (17) and the side wall (18) of the foundation pit. S8: Place pads (6) on the surface of the top plate (12) of the underground silo structure (3), lay a barrier layer (21) composed of steel mesh (20) and geotextile (16), and set a secondary enclosure structure (17) on the outside of the side wall of the entrance (13). S9: Backfill the surface of the top plate (12) of the underground silo structure (3) and the outside of the secondary enclosure structure (17) with fluidized solidified soil (19) in layers, and reserve a certain thickness of topsoil (22) for backfilling. S10: Inject non-aqueous reactive slow-setting and solidifying expansive polymer material (5) into the continuous cavity (23) outside the steel formwork (10), the side wall (8) of the underground silo structure (3), the top plate (12) and the entrance (13) through the grouting pipe (11). Grouting is carried out while the pipe is pulled out until the polymer material overflows from the entrance (13) elevation into the cavity, thus completing the integrated construction of the seepage prevention and insulation layer (24).

[0009] In the above technical solution, in step S3, the pad block (6) is a cube with a side length of 100mm, which is made of non-aqueous reaction slow-setting curing expansion polymer material (5); the spacing of the pad blocks (6) within the bottom plate (7) of the underground silo structure (3) is 1m, and the spacing of the pad blocks (6) at the intersection of the bottom plate (7) and the side wall (8) is increased to 50cm; the elevation control error of the pad block (6) is within ±1mm.

[0010] In the above technical solution, in step S4, the steel template (10) is fully welded and assembled into a whole on the ground surface, and after rust removal and keeping the upper surface clean, it is hoisted as a whole.

[0011] In the above technical solution, in step S5, the diameter of the grouting pipe (11) is 8mm, the horizontal circumferential spacing is 6m, and the grouting pipe (11) is a seamless steel pipe.

[0012] In the above technical solution, in step S7, the secondary enclosure structure (17) is set 100mm outside the side wall (8) of the underground silo structure (3), and is composed of circumferential steel bars (14) with a height of 1m, vertical steel bars (15) and geotextile (16).

[0013] In the above technical solution, in step S8, the barrier layer (21) is used to prevent the unsolidified fluidized solidified soil (19) from leaking, and the joint between the barrier layer (21) and the geotextile (16) of the secondary retaining structure (17) is tightly bound.

[0014] In the above technical solution, in step S9, a layer of 200mm thick fluidized solidified soil (19) is first backfilled on the surface of the top plate (12) of the underground silo structure (3). After it solidifies, it is backfilled in layers to 800mm below the design zero. The 800mm interval is backfilled with cultivated soil (22) to the design zero.

[0015] In the above technical solution, in step S10, the width of the continuous cavity (23) is 100mm, including the lower part of the steel template (10), the outer side of the side wall (8) of the underground silo structure (3), the upper side of the top plate (12) and the outer side of the entrance (13); the pipe pulling speed is determined according to the volume of the continuous cavity (23), the density of the non-aqueous reaction slow-setting and solidifying expansion polymer material (5), and the grouting flow rate.

[0016] The advantages and beneficial effects of this invention are as follows: (1) It avoids leakage and insulation failure caused by material overlap and backfill damage during the construction of traditional flexible waterproof and insulation layers.

[0017] (2) By constructing a continuous cavity and grouting in one piece, a complete and seamless waterproof and heat-insulating layer is formed, which significantly improves the overall waterproof and heat-insulating performance of the underground silo structure.

[0018] (3) Non-aqueous reaction slow-setting and curing expansion polymer materials can actively fill and compact cavities during the slow-setting and expansion process, ensuring that the integrated seepage prevention and insulation layer is closely bonded to the structure and backfill soil, and will not cause stress cracking due to post-construction settlement, and have stable long-term performance.

[0019] (4) The construction process is highly standardized, which reduces the judgment errors, interventions and material waste of different professionals, which helps to ensure construction quality and shorten the construction period. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic cross-sectional view of the integrated seepage-proof and heat-insulating layer of the underground silo structure after the completion of construction according to the present invention.

[0022] Figure 2 This is a diagram illustrating the backfilling construction process of the underground silo structure involved in the construction of this invention.

[0023] Figure 3 This is a plan view of the installation of the pad block and the pre-set plan of the grouting pipe involved in the construction of this invention.

[0024] Figure 4 This is a detailed structural drawing of the cubic pad block involved in the construction of this invention.

[0025] Figure 5 This is a detailed structural drawing of the triangular steel pad involved in the construction of this invention.

[0026] Figure 6 This is a detailed structural drawing of the steel formwork involved in the construction of this invention.

[0027] Figure 7 This is a detailed structural drawing of the steel mesh involved in the construction of this invention.

[0028] Figure 8 These are three views of the secondary maintenance structure involved in the construction of this invention. Detailed Implementation

[0029] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0030] This invention provides an integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure, specifically including the following steps: S1: Level the foundation 1 and construct the concrete cushion layer 2.

[0031] S2: Measure and lay out the lines, and draw the planar range marking lines 4 of the underground silo structure 3 on the surface of the concrete foundation 2.

[0032] S3: Within the marked area 4, multiple cubic blocks 6 with a side length of 100mm, made of non-aqueous reactive slow-setting expanding polymer material 5, are installed. Within the base slab 7 of the underground silo structure 3, the blocks 6 are spaced 1m apart; at the intersection of the base slab 7 and the side wall 8, the spacing is increased to 50cm. Using a laser level in conjunction with triangular steel shims 9 of varying thicknesses, the elevation of the leveling blocks 6 is precisely controlled, with the overall error accuracy controlled within ±1mm.

[0033] S4: The lower part of the base plate 7 of the underground silo structure 3 uses steel formwork 10, which is fully welded and assembled into a whole on the ground surface. After rust removal treatment, the upper surface is kept clean, and then the whole structure is hoisted. According to the plane range marking line 4 on the surface of the concrete foundation 2, the steel formwork 10 is precisely installed on the pad block 6.

[0034] S5: In the cavity between the lower part of the steel formwork 10 and the concrete cushion layer 2, grouting pipes 11 with a diameter of 8mm are evenly embedded around the perimeter along the plane range marking line 4, with a horizontal circumferential spacing of 6m. The length of a single grouting pipe 11 starts from the lower grout outlet, passes sequentially through the side wall 8 and top plate 12 of the underground silo structure 3, and ends at the upper grout inlet 1000mm above the elevation of the entrance / exit 13. Seamless steel pipes are preferred for the grouting pipes 11.

[0035] S6: The construction of the underground silo structure 3, including the bottom slab 7, side walls 8, top slab 12, entrance and exit 13, etc., is carried out in sequence, including conventional contents such as rebar binding, formwork fixing, concrete pouring, vibration and curing.

[0036] S7: At a distance of 100mm from the outer sidewall 8 of the underground silo structure 3, a secondary retaining structure 17 is constructed using circumferential reinforcing bars 14 (1m high), vertical reinforcing bars 15, and geotextile 16. The area between the outer side of the secondary retaining structure 17 and the sidewall 18 of the foundation pit is backfilled with fluidized solidified soil 19. Construction is then carried out cyclically until the top slab 12 of the underground silo structure 3 reaches elevation 12.

[0037] S8: On the surface of the top slab 12 of the underground silo structure 3, clean away any foreign objects and evenly place pad blocks 6 at 1m intervals. Lay a barrier layer 21 composed of steel mesh 20 and geotextile 16 to prevent leakage of uncured fluidized solidified soil 19. At 100mm outside the side wall of the entrance 13 of the underground silo structure 3, use the same secondary retaining structure 17 as the side wall 8. Securely tie the joint between the barrier layer 21 and the geotextile 16 of the secondary retaining structure 17.

[0038] S9: A 200mm thick layer of fluidized solidified soil 19 is backfilled onto the surface of the top slab 12 of the underground silo structure 3. After it solidifies and gains sufficient strength, the fluidized solidified soil 19 is backfilled in layers. The backfill thickness of the fluidized solidified soil 19 is not less than 2m, and the elevation is ±800mm below the design elevation of the underground silo structure 3. This 800mm interval is backfilled with topsoil 22 to the design elevation to preserve the land's planting or greening function.

[0039] S10: Start the grouting equipment and inject non-aqueous reactive slow-setting and curing expandable polymer material 5 into the 100mm wide continuous cavity 23 formed by the grouting pipe 11, which is located below the steel formwork 10, outside the side wall 8 of the underground silo structure 3, above the top plate 12, and outside the inlet / outlet 13. Determine the pipe pulling speed based on the volume of the continuous cavity 23, the density of the non-aqueous reactive slow-setting and curing expandable polymer material 5, and the grouting flow rate. Grout while pulling the pipe until the non-aqueous reactive slow-setting and curing expandable polymer material 5 overflows from the cavity at the inlet / outlet 13 elevation of the underground silo structure 3, thus completing the integrated construction of the seepage-proof and heat-insulating layer 24.

[0040] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0041] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for integrated construction of an anti-seepage and thermal insulation layer for an underground silo structure, characterized in that, Includes the following steps: S1: Level the foundation (1) and construct the concrete cushion layer (2). S2: Measure and lay out the lines, and draw the plane range marking lines (4) of the underground silo structure (3) on the surface of the concrete cushion layer (2). S3: Place a pad (6) made of non-aqueous reaction slow-curing expansion polymer material (5) within the plane range marking line (4), and precisely control the elevation of the pad (6) by means of a laser level and a triangular steel pad (9); S4: The steel formwork (10) is hoisted as a whole and precisely installed on the pad (6) according to the plane range marking line (4); S5: Pre-embed grouting pipes (11) evenly around the plane range marking line (4). The grout outlet at the lower end of the grouting pipe (11) is located in the cavity between the lower part of the steel formwork (10) and the concrete cushion layer (2), and the grout inlet at the upper end extends to the elevation above the inlet (13). S6: Construct the bottom slab (7), side walls (8), top slab (12) and entrance (13) of the underground silo structure (3) in sequence. S7: A secondary retaining structure (17) consisting of circumferential steel bars (14), vertical steel bars (15) and geotextile (16) is set on the outside of the side wall (8) of the underground silo structure (3), and fluidized solidified soil (19) is backfilled between the outside of the secondary retaining structure (17) and the side wall (18) of the foundation pit. S8: Place pads (6) on the surface of the top plate (12) of the underground silo structure (3), lay a barrier layer (21) composed of steel mesh (20) and geotextile (16), and set a secondary enclosure structure (17) on the outside of the side wall of the entrance (13). S9: Backfill the surface of the top plate (12) of the underground silo structure (3) and the outside of the secondary enclosure structure (17) with fluidized solidified soil (19) in layers, and reserve a certain thickness of topsoil (22) for backfilling. S10: Inject non-aqueous reactive slow-setting and solidifying expansive polymer material (5) into the continuous cavity (23) outside the steel formwork (10), the side wall (8) of the underground silo structure (3), the top plate (12) and the entrance (13) through the grouting pipe (11). Grouting is carried out while the pipe is pulled out until the polymer material overflows from the entrance (13) elevation into the cavity, thus completing the integrated construction of the seepage prevention and insulation layer (24).

2. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S3, the pad block (6) is a cube with a side length of 100mm, and is made of non-aqueous reaction slow-setting curing expansion polymer material (5); the spacing of the pad blocks (6) within the bottom plate (7) of the underground silo structure (3) is 1m, and the spacing of the pad blocks (6) at the intersection of the bottom plate (7) and the side wall (8) is increased to 50cm; the elevation control error of the pad block (6) is within ±1mm.

3. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S4, the steel template (10) is fully welded and assembled on the ground, and after rust removal and keeping the upper surface clean, it is hoisted as a whole.

4. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S5, the grouting pipe (11) has a diameter of 8mm and a circumferential horizontal spacing of 6m. The grouting pipe (11) is a seamless steel pipe.

5. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S7, the secondary enclosure structure (17) is set 100mm outside the side wall (8) of the underground silo structure (3), and is composed of circumferential steel bars (14) with a height of 1m, vertical steel bars (15) and geotextile (16).

6. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S8, the barrier layer (21) is used to prevent leakage of the uncured fluidized solidified soil (19), and the joint between the barrier layer (21) and the geotextile (16) of the secondary retaining structure (17) is tightly bound.

7. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S9, a layer of 200mm thick fluidized solidified soil (19) is first backfilled on the surface of the top plate (12) of the underground silo structure (3). After it solidifies, it is backfilled in layers to 800mm below the design zero. The 800mm interval is backfilled with topsoil (22) to the design zero.

8. The integrated construction method for the seepage-proof and heat-insulating layer of an underground silo structure according to claim 1, characterized in that, In step S10, the width of the continuous cavity (23) is 100mm, including the lower part of the steel template (10), the outer side of the side wall (8) of the underground silo structure (3), the upper side of the top plate (12), and the outer side of the entrance (13); the pipe pulling speed is determined according to the volume of the continuous cavity (23), the density of the non-aqueous reaction slow-setting and solidifying expansion polymer material (5), and the grouting flow rate.

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