Filling type series large karst cave pile foundation double-liquid grouting treatment construction method

Abstract

The invention relates to the technical field of pile foundation construction, in particular to a filling type series large karst cave pile foundation double-liquid grouting treatment construction method. The method comprises the following steps: obtaining a three-dimensional space image in a karst cave based on electromagnetic tomography CT, and analyzing the three-dimensional space image based on a karst cave safety index to generate an analysis result; the analysis result is substituted into a correlation formula to calculate a karst cave construction safety coefficient, whether the karst cave construction safety coefficient exceeds a preset safety coefficient threshold value or not is judged, and if yes, the soil texture above the karst cave in the vertical direction of the drill hole and the soil texture below the karst cave are collected; based on the parameter data, calculating a first average permeability corresponding to the soil texture above the solution cavern and a second average permeability corresponding to the soil texture below the solution cavern; and slurry is prepared according to the first average permeability and the second average permeability, and grouting is completed. According to the construction method, the construction safety and the mechanical property of the pile foundation can be improved when the filling type series-through large karst cave pile foundation is constructed.

Description

Technical Field

[0001] The invention relates to the technical field of pile foundation construction, and in particular to a double-liquid grouting treatment construction method for a filling-type large-cavity pile foundation. Background Art

[0002] In the field of civil engineering, especially in pile foundation engineering, karst caves are a common geological phenomenon. The existence of karst caves often brings great challenges to pile foundation construction, because they may cause the pile body to become unstable, reduce bearing capacity, and even cause serious safety accidents. Therefore, how to effectively deal with karst caves and ensure the stability and safety of pile foundations has always been the focus of the engineering community.

[0003] Filled interconnected large caves are a special type of caves, characterized by the presence of a large amount of filling materials such as sand, mud, gravel, etc., and the caves are often interconnected to form a complex cave network. This type of cave has a more significant impact on pile foundation construction, because the presence of filling materials not only increases the difficulty of pile foundation construction, but also may cause the loss of grouting slurry, making it impossible to achieve the expected grouting effect.

[0004] In the prior art, in the grouting treatment of the filling type interlinked large cave pile foundation, a banana growth detection system and method based on hyperspectral is urgently needed to solve the above problems. Summary of the invention

[0005] The purpose of the present invention is to provide a double-liquid grouting treatment construction method for a filled large cave pile foundation: to solve the technical problem in the existing solution that the grouting slurry is lost due to the presence of fillers in the large cave, thereby causing the formed pile foundation to have low mechanical properties.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A double-liquid grouting treatment construction method for a filling type large cave pile foundation, the method comprising:

[0008] Drill holes according to the measured positions to form pile holes;

[0009] A three-dimensional spatial image of the interior of the cave is obtained based on electromagnetic wave tomography CT, and the three-dimensional spatial image is analyzed based on the cave safety index to generate an analysis result, wherein the cave safety index includes the cave filling type index, the cave integrity index and the cave roof rock layer thickness index;

[0010] Substitute the analytical results into the correlation formula to calculate the cave construction safety factor, and determine whether the cave construction safety factor exceeds the preset safety factor threshold. If so, collect the soil above the cave and the soil below the cave in the vertical direction of the borehole;

[0011] Detect parameter data of soil above the cave and soil below the cave respectively;

[0012] Calculate the first average permeability corresponding to the soil above the cave and the second average permeability corresponding to the soil below the cave based on the parameter data;

[0013] The slurry is prepared according to the first average permeability and the second average permeability, and the grouting is completed.

[0014] Furthermore, the three-dimensional space image is analyzed based on the cave safety index, and the generation of the analysis result includes the following process:

[0015] Based on the cave filling type index, different types of cave fillings in the three-dimensional space image are identified through convolutional neural network, and the positions of different types of cave fillings are determined based on GIS to obtain the location information of the cave fillings. Based on the pile hole position and the cave filling position information, the sum S of the distance between the pile hole and the cave filling position is calculated;

[0016] The karst cave integrity coefficient is obtained based on the karst cave integrity index and the three-dimensional space image: the three-dimensional space image and the karst cave integrity index are judged to determine whether there is stratum movement in the rock layer where the karst cave is located, whether there is collapse, cracks, and water flow at the entrance of the karst cave, and whether there is water gushing in the karst cave. The number of stratum movement, collapse, cracks, water flow, and water gushing in the three-dimensional space image is calculated, and the ratio of the number of phenomena to the number of karst cave integrity indexes is calculated to obtain the ratio value P;

[0017] Based on the position of the borehole in the karst cave in the three-dimensional space image, the vertical drilling distance of the borehole is obtained, and it is determined whether the drilling distance exceeds the preset distance of the cave roof rock layer thickness index. If so, the drilling distance is used as the cave roof rock layer thickness R;

[0018] The sum S of the distances between the pile hole and the cave filling position, the ratio value P, and the thickness R of the cave roof rock layer are recorded as analytical results.

[0019] Furthermore, substituting the analytical results into the correlation formula to calculate the cave construction safety factor specifically includes the following process:

[0020] Substitute the sum of the distances S between the pile hole and the location of the cave filling, the ratio value P, and the thickness of the cave roof rock layer R into the correlation formula to calculate the cave construction safety factor LMS. The correlation formula is as follows:

[0021]

[0022] Among them, J is the maximum height of the upper and lower boundaries of the cave, which is measured on the cave, d is the width of the pile hole, Y is the width of the steel casing, and π is taken as 3.14.

[0023] Furthermore, calculating the first average permeability corresponding to the soil above the cave and the second average permeability corresponding to the soil below the cave based on the parameter data specifically includes the following process:

[0024] Obtaining parameter data corresponding to the soil above the cave, the parameter data corresponding to the soil above the cave includes the proportion of sub-clay, the proportion of silt, and the proportion of rock;

[0025] Determine the weights of sub-clay, silt sand, and rock: the weights of sub-clay, silt sand, and rock are K1, K2, and K3 respectively, where K3>K2>K1;

[0026] The first porosity M1 is obtained according to the correlation formula, which is as follows:

[0027]

[0028] Among them, Af, As, and Ad are the proportion of sub-clay, silt, and rock in the soil, respectively; V1 is the total volume of the soil sampled above the cave; and E is a constant coefficient, which is determined according to the total volume of the soil sampled above the cave V1. The larger V1 is, the larger E is.

[0029] The first porosity M is recorded as the first average permeability;

[0030] Furthermore, calculating the second average permeability corresponding to the soil below the cave based on the parameter data specifically includes the following process:

[0031] Obtain the parameter data of the soil beneath the cave, including the proportion of muddy coarse sandstone, the proportion of broken and strongly weathered sandstone, the proportion of other filling materials, and the water content;

[0032] Determine the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillings: the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillings are K4, K5, and K6 respectively;

[0033] The second porosity M2 is obtained according to the correlation formula, which is as follows:

[0034]

[0035] Among them, Aj, Ak, and Al are the proportion of muddy coarse sandstone, the proportion of broken and strongly weathered sandstone, and the proportion of other filling materials, respectively; V2 is the total volume of the soil sampled below the cave; G is a constant coefficient, which is determined according to the total volume of the soil sampled below the cave V2. The larger V2 is, the larger G is.

[0036] By calculating the proportion of water content to the total amount of soil below the cave, the average water density μ is obtained. The second average permeability X is obtained by correlating the average porosity M2 and the average water density μ. The correlation formula is:

[0037]

[0038] Where β is the permeability parameter, 0.25≤β≤0.6.

[0039] Further, configuring the slurry according to the first average permeability and the second average permeability includes the following process:

[0040] Dividing the index interval according to the first average permeability and the second average permeability;

[0041] If the average permeability is in the first index interval, the first slurry is determined as follows: cement accounts for 30%, water accounts for 20%, fly ash accounts for 30%, chelating agent accounts for 5%, clay accounts for 2%, fly ash accounts for 5%, and diatomaceous earth accounts for 8%;

[0042] If the average permeability is in the second index interval, the second slurry is determined as follows: cement accounts for 20%, water accounts for 15%, fly ash accounts for 45%, chelating agent accounts for 8%, clay accounts for 4%, fly ash accounts for 3%, and diatomaceous earth accounts for 5%;

[0043] If the average permeability is in the third index interval, the third slurry is determined: cement accounts for 27%, water accounts for 10%, fly ash accounts for 43%, chelating agent accounts for 10%, clay accounts for 5%, fly ash accounts for 3%, and diatomaceous earth accounts for 2%.

[0044] Furthermore, a double-liquid grouting treatment construction method is used for grouting.

[0045] Furthermore, before drilling holes according to the measured positions to form pile holes, the pile foundation points are explored, the geological conditions at the surveyed locations are analyzed, and preliminary construction preparations are made with relatively complete geological data. In addition to the basic construction preparations of three connections and one leveling, sufficient soil, stone slabs and steel casings required for backfilling are prepared.

[0046] Furthermore, when grouting, when it is about 1m close to the top of the cave, increase the mud density, impact with a small stroke, gradually penetrate the top, and strengthen the monitoring of the mud surface changes in the hole. When the mud surface in the hole drops significantly, immediately lift the hammer, replenish mud in time, backfill clay, stone and bagged cement, and stop for a preset time. During the stop period, if the mud in the hole continues to drop, replenish mud and backfill the mixture at any time. After the mud in the hole stabilizes, continue to punch the hole, use a small stroke to impact and drop the mixture, so that it squeezes into the cave and blocks the cave channel. During the impact process, the mud in the hole will drop many times. Each time the mud drops, lift the hammer in time, replenish mud and backfill clay and stone, and stop punching for one day, and continue punching after it stabilizes. Repeat this cycle until the pile hole no longer leaks mud and passes through the cave.

[0047] Compared with the existing solutions, the present invention achieves the following beneficial effects:

[0048] The present invention drills holes according to the measured positions to form pile holes, obtains a three-dimensional space image inside the cave based on electromagnetic wave tomography CT, analyzes the three-dimensional space image based on the cave safety index to generate an analysis result, substitutes the analysis result into a correlation formula to calculate the cave construction safety factor, and judges whether the filled-type interconnected large cave meets the grouting safety conditions based on the cave construction safety factor, thereby improving the safety of construction.

[0049] In addition, by calculating the first average permeability of the soil above the cave and the second average permeability of the soil below the cave based on the parameter data, configuring the slurry according to the first average permeability and the second average permeability, and completing the grouting, the mechanical properties of the formed pile foundation can be improved, and the construction quality and efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For ordinary technicians in this field, other drawings can also be obtained based on these drawings.

[0051] Figure 1 It is a flow chart of a double-liquid grouting treatment construction method for a filling-type large-cavity pile foundation according to an embodiment of the present invention;

[0052] Figure 2 It is a flow chart of another filling type large cave pile foundation double liquid grouting treatment construction method according to an embodiment of the present invention;

[0053] Figure 3 It is a flow chart of another double-liquid grouting treatment construction method for a filling-type large cave pile foundation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0055] In addition, the described features, structures or characteristics may be combined in one or more example embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the example embodiments of the present disclosure. However, those skilled in the art will appreciate that the technical solutions of the present disclosure may be practiced while omitting one or more of the specific details, or other methods, components, steps, etc. may be adopted. In other cases, well-known structures, methods, implementations or operations are not shown or described in detail to avoid obscuring various aspects of the present disclosure.

[0056] This embodiment provides a double-liquid grouting treatment construction method for a filling type large cave pile foundation. Figure 1 Flow chart of a double-liquid grouting treatment construction method for a filling type large cave pile foundation according to an embodiment of the present invention, as shown in FIG. Figure 1 As shown, the method comprises the following steps:

[0057] Step S101, drilling according to the measurement position to form a pile hole;

[0058] Step S102, obtaining a three-dimensional spatial image of the interior of the cave based on electromagnetic wave tomography CT, parsing the three-dimensional spatial image based on the cave safety index, and generating an analysis result, wherein the cave safety index includes a cave filling type index, a cave integrity index, and a cave roof rock thickness index;

[0059] Step S103, substituting the analytical result into the correlation formula to calculate the safety factor of the cave construction;

[0060] Step S104, determining whether the cave construction safety factor exceeds a preset safety factor threshold, if so, proceeding to step S105, if not, proceeding to step S108;

[0061] Step S105, detecting parameter data of the soil above the cave and the soil below the cave respectively;

[0062] Step S106, calculating a first average permeability corresponding to the soil above the cave and a second average permeability corresponding to the soil below the cave based on the parameter data;

[0063] Step S107, preparing slurry according to the first average permeability and the second average permeability, and completing grouting;

[0064] Step S108, stop construction and reselect the measurement position.

[0065] In summary, the present invention drills holes according to the measurement position to form pile holes, obtains a three-dimensional space image inside the cave based on electromagnetic wave tomography CT, analyzes the three-dimensional space image based on the cave safety index, generates an analysis result, substitutes the analysis result into the correlation formula to calculate the cave construction safety factor, and judges whether the filled-type connected large cave meets the grouting safety conditions based on the cave construction safety factor, which can improve the safety of construction. Based on the parameter data, the first average permeability corresponding to the soil above the cave and the second average permeability corresponding to the soil below the cave are calculated, the slurry is configured according to the first average permeability and the second average permeability, and the grouting is completed, which can improve the mechanical properties of the formed pile foundation and improve the construction quality and efficiency.

[0066] In some embodiments, before step S101, the primary task of treating karst caves in pile foundation construction is to explore the pile foundation points, analyze the geological conditions of the location where the survey is conducted, and make preparations for the early stage of construction with relatively complete geological data. In addition to the basic construction preparations of three connections and one leveling, it is also necessary to prepare enough soil, the pieces required for backfilling and steel casing, and to promptly treat the karst caves that appear during the pile foundation construction process. Before drilling holes in pile foundation construction, remember not to place too heavy equipment near the hole to prevent construction losses caused by hole collapse. For the purpose of karst cave treatment, it is advisable to set up hoisting and towing equipment of sufficient tonnage at the pile foundation construction site; if the pile foundation construction is carried out in water, the stability of the construction platform should also be considered.

[0067] In some embodiments, in step S102, a three-dimensional spatial image of the interior of the cave is obtained based on electromagnetic wave tomography CT, and the three-dimensional spatial image is analyzed based on the cave safety index to generate an analysis result, which specifically includes the following process:

[0068] Based on the cave filling type index, different types of cave fillings in the three-dimensional space image are identified through a convolutional neural network, and the positions of different types of cave fillings are determined based on GIS (Geographic Information System) to obtain the location information of the cave fillings, and the sum S of the distances between the pile hole and the cave filling position is calculated based on the pile hole position and the cave filling position information;

[0069] The karst cave integrity coefficient is obtained based on the karst cave integrity index and the three-dimensional space image: the three-dimensional space image and the karst cave integrity index are judged to determine whether there is stratum movement in the rock layer where the karst cave is located, whether there is collapse, cracks, and water flow at the entrance of the karst cave, and whether there is water gushing in the karst cave. The number of stratum movement, collapse, cracks, water flow, and water gushing in the three-dimensional space image is calculated, and the ratio of the number of phenomena to the number of karst cave integrity indexes is calculated to obtain the ratio value P;

[0070] Based on the position of the borehole in the karst cave in the three-dimensional space image, the vertical drilling distance of the borehole is obtained, and it is determined whether the drilling distance exceeds the preset distance of the cave roof rock layer thickness index. If so, the drilling distance is used as the cave roof rock layer thickness R;

[0071] The sum S of the distances between the pile hole and the cave filling position, the ratio value P, and the thickness R of the cave roof rock layer are recorded as analytical results.

[0072] It is worth mentioning that electromagnetic wave tomography (Computed Tomography), also known as electromagnetic wave CT technology, is an advanced technology that detects the internal spatial structure of an object by emitting electromagnetic waves and using the physical and electrical differences of electromagnetic waves in the propagation medium. This technology is widely used in engineering geological exploration, especially in detecting complex underground spaces such as caves, rocks, and broken zones. In terms of exploring the situation inside the cave, the working principle of electromagnetic wave tomography CT technology is to transmit radio waves with a frequency of 0.5 to 32 MHz and use receiving equipment to capture electromagnetic waves that have propagated and changed after passing through different media. In the underground space, different materials have different absorption and reflection characteristics of electromagnetic waves. Using these characteristics, electromagnetic wave tomography CT technology can construct a three-dimensional spatial image of the inside of the detected object, and then understand the specific structure and distribution of the cave. In terms of specific applications, electromagnetic wave tomography CT technology first needs to drill holes on the ground or underground, and set up transmitting and receiving equipment in the holes. By transmitting electromagnetic waves underground and receiving the reflected signals, the structural information of the underground space can be obtained. In cave detection, this technology can reveal information such as the size, shape, location of the cave and the nature of the filling inside the cave.

[0073] Among them, the cave safety indicators include the cave filling type indicator, the cave integrity indicator and the cave roof rock layer thickness indicator. The cave filling type indicator is the preset cave filling type, which may include silt clay, sand, individual gravel and a small amount of sandstone, limestone debris, sub-clay, silt sand, gravel-containing sub-clay, sandy strongly weathered sandstone and muddy siltstone, fragmented strongly weathered siltstone, slightly weathered limestone, etc. The cave integrity indicator includes the occurrence of rock strata movement, collapse, cracks, water flow, and water gushing.

[0074] In some embodiments, in step S103, substituting the analytical result into the correlation formula to calculate the cave construction safety factor specifically includes the following process:

[0075] Substitute the sum of the distances S between the pile hole and the location of the cave filling, the ratio value P, and the thickness of the cave roof rock layer R into the correlation formula to calculate the cave construction safety factor LMS. The correlation formula is as follows:

[0076]

[0077] Among them, J is the maximum height of the upper and lower boundaries of the cave, which is measured on the cave, d is the width of the pile hole, Y is the width of the steel casing, and π is taken as 3.14.

[0078] In some embodiments, Figure 2 FIG. 1 is a flow chart of another method for double-liquid grouting treatment of a filling type large cave pile foundation according to an embodiment of the present invention. Figure 2 As shown, calculating the first average permeability corresponding to the soil above the cave based on the parameter data specifically includes the following steps:

[0079] Step S201, obtaining parameter data corresponding to the soil above the cave, wherein the parameter data corresponding to the soil above the cave includes the proportion of sub-clay, the proportion of silt, and the proportion of rock;

[0080] Step S202, determining the weights corresponding to sub-clay, silt sand, and rock: the weights corresponding to sub-clay, silt sand, and rock are K1, K2, and K3, respectively, wherein K3>K2>K1;

[0081] Step S203, obtaining the first porosity M1 according to a correlation formula, the correlation formula is as follows:

[0082]

[0083] Among them, Af, As, and Ad are the proportion of sub-clay, silt, and rock in the soil, respectively; V1 is the total volume of the soil sampled above the cave; and E is a constant coefficient, which is determined according to the total volume of the soil sampled above the cave V1. The larger V1 is, the larger E is.

[0084] Step S204: record the first porosity M as the first average permeability.

[0085] In some embodiments, Figure 3 FIG. 1 is a flow chart of another method for double-liquid grouting treatment of a filling type large cave pile foundation according to an embodiment of the present invention. Figure 3 As shown, calculating the second average permeability corresponding to the soil below the cave based on the parameter data specifically includes the following steps:

[0086] Step S301, obtaining parameter data of the soil below the cave, the parameter data of the soil below the cave including the proportion of muddy coarse sandstone, the proportion of broken blocky strongly weathered sandstone, the proportion of other filling materials and the water content;

[0087] Step S302, determining the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillers: the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillers are K4, K5, and K6 respectively;

[0088] Step S303, obtaining a second porosity M2 according to a correlation formula, the correlation formula is as follows:

[0089]

[0090] Among them, Aj, Ak, and Al are the proportion of muddy coarse sandstone, the proportion of broken and strongly weathered sandstone, and the proportion of other filling materials, respectively; V2 is the total volume of the soil sampled below the cave; G is a constant coefficient, which is determined according to the total volume of the soil sampled below the cave V2. The larger V2 is, the larger G is.

[0091] Step S304, by calculating the ratio of water content to the total amount of soil below the cave, the average water density μ is obtained, and the second average permeability X is obtained by correlating the average porosity M2 and the average water density μ. The correlation formula is:

[0092]

[0093] Where β is the permeability parameter, 0.25≤β≤0.6.

[0094] In some embodiments, configuring the slurry according to the first average permeability and the second average permeability comprises the following process:

[0095] Dividing the index interval according to the first average permeability and the second average permeability;

[0096] If the average permeability is in the first index interval, the first slurry is determined as follows: cement accounts for 30%, water accounts for 20%, fly ash accounts for 30%, chelating agent accounts for 5%, clay accounts for 2%, fly ash accounts for 5%, and diatomaceous earth accounts for 8%;

[0097] If the average permeability is in the second index interval, the second slurry is determined as follows: cement accounts for 20%, water accounts for 15%, fly ash accounts for 45%, chelating agent accounts for 8%, clay accounts for 4%, fly ash accounts for 3%, and diatomaceous earth accounts for 5%;

[0098] If the average permeability is in the third index interval, the third slurry is determined: cement accounts for 27%, water accounts for 10%, fly ash accounts for 43%, chelating agent accounts for 10%, clay accounts for 5%, fly ash accounts for 3%, and diatomaceous earth accounts for 2%.

[0099] In some embodiments, a double-liquid grouting treatment construction method is used for grouting: when it is about 1m close to the top plate of the cave, the mud specific gravity is increased, and a small stroke impact is used to gradually penetrate the top plate. At the same time, the monitoring of the changes in the mud surface in the hole is strengthened. When the mud surface in the hole is found to drop significantly, the hammer is immediately lifted, the mud is replenished in time, and clay, stone and bagged cement (weight ratio 1:1:0.2) are backfilled, and it is stopped for a period of time (generally 24 hours). During the stop period, if the mud in the hole continues to drop, the mud and the mixture are replenished at any time. After the mud in the hole is stable, the hole is punched again, and the mixture is thrown down with a small stroke impact to squeeze it into the cave and block the cave passage. During the impact process, the mud in the hole will drop many times. Each time the mud drops, the hammer is lifted in time, the mud is replenished and clay and stone are backfilled, and the punching is stopped for one day, and the punching is continued after it is stable. This cycle is repeated until the pile hole no longer leaks slurry and passes through the cave.

[0100] When pouring concrete, it should be done compactly and continuously, and it is strictly forbidden to stop work in the middle. During the pouring process, prevent the concrete mixture from overflowing from the top of the funnel or falling from the outside of the funnel into the bottom of the hole; observe the drop of concrete in the pipe and the rise and fall of the water level in the hole, measure the height of the concrete surface in the hole in time, and guide the lifting and removal of the catheter. When removing the catheter, on the basis of ensuring safety, the removal time should not exceed 15 minutes, and bolts, rubbers and various tools should be prevented from falling into the hole. Since cave pile foundations are prone to collapse, if the water or mud water level in the hole casing suddenly rises and overflows during the pouring process, and then drops sharply and bubbles emerge, it may be a sign of collapse. The depth can be measured with a hammer, and compared with the last depth measurement value and the amount of concrete poured to determine whether the hole has collapsed.

[0101] The above embodiments can be implemented in whole or in part by software, hardware, firmware or any other combination. When implemented by software, the above embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the process or function described in the embodiment of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website site, computer, server or data center to another website site, computer, server or data center by wired (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that contains one or more available media sets. The available medium can be a magnetic medium (e.g., a floppy disk, a hard disk, a tape), an optical medium (e.g., a DVD), or a semiconductor medium. The semiconductor medium can be a solid-state hard disk.

[0102] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0103] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0104] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only some logical function divisions. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0105] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0106] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A double-liquid grouting treatment construction method for a filling type large cave pile foundation, characterized in that the method include: Drill holes according to the measured positions to form pile holes; A three-dimensional spatial image of the interior of the cave is obtained based on electromagnetic wave tomography CT, and the three-dimensional spatial image is analyzed based on the cave safety index to generate an analysis result, wherein the cave safety index includes the cave filling type index, the cave integrity index and the cave roof rock layer thickness index; Substitute the analytical results into the correlation formula to calculate the cave construction safety factor, and determine whether the cave construction safety factor exceeds the preset safety factor threshold. If so, collect the soil above the cave and the soil below the cave in the vertical direction of the borehole; Detect parameter data of soil above the cave and soil below the cave respectively; Calculate the first average permeability of the soil above the cave and the second average permeability of the soil below the cave based on the parameter data; The slurry is configured according to the first average permeability and the second average permeability, and the grouting is completed.

2. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: The three-dimensional space image is analyzed based on the cave safety index, and the analysis results are generated including the following processes: Based on the cave filling type index, different types of cave fillings in the three-dimensional space image are identified through convolutional neural network, and the positions of different types of cave fillings are determined based on GIS to obtain the location information of the cave fillings. Based on the pile hole position and the cave filling position information, the sum S of the distance between the pile hole and the cave filling position is calculated; The karst cave integrity coefficient is obtained based on the karst cave integrity index and the three-dimensional space image: the three-dimensional space image and the karst cave integrity index are judged to determine whether there is stratum movement in the rock layer where the karst cave is located, whether there is collapse, cracks, and water flow at the entrance of the karst cave, and whether there is water gushing in the karst cave. The number of stratum movement, collapse, cracks, water flow, and water gushing in the three-dimensional space image is calculated, and the ratio of the number of phenomena to the number of karst cave integrity indexes is calculated to obtain the ratio value P; Based on the position of the borehole in the karst cave in the three-dimensional space image, the vertical drilling distance of the borehole is obtained, and it is determined whether the drilling distance exceeds the preset distance of the cave roof rock layer thickness index. If so, the drilling distance is used as the cave roof rock layer thickness R; The sum S of the distances between the pile hole and the cave filling position, the ratio value P, and the thickness R of the cave roof rock layer are recorded as analytical results.

3. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 2, characterized in that: Substituting the analytical results into the correlation formula to calculate the safety factor of cave construction specifically includes the following process: Substitute the sum of the distances S between the pile hole and the cave filling, the ratio value P, and the cave roof rock thickness R into the correlation formula to calculate the cave construction safety factor LMS. The correlation formula is as follows: Among them, J is the maximum height value of the upper and lower boundaries of the cave, which is measured on the cave, d is the width of the pile hole, Y is the width of the steel casing, and π is taken as 3.

14.

4. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: The calculation of the first average permeability corresponding to the soil above the cave based on the parameter data specifically includes the following process: Obtaining parameter data corresponding to the soil above the cave, wherein the parameter data corresponding to the soil above the cave includes the proportion of sub-clay, the proportion of silt, and the proportion of rock; Determine the weights of sub-clay, silt sand, and rock: the weights of sub-clay, silt sand, and rock are K1, K2, and K3 respectively, where K3>K2>K1; The first porosity M1 is obtained according to the correlation formula, which is as follows: Among them, Af, As, and Ad are the proportion of sub-clay, silt, and rock in the soil, respectively; V1 is the total volume of the soil sampled above the cave; and E is a constant coefficient, which is determined according to the total volume of the soil sampled above the cave V1. The larger V1 is, the larger E is. The first porosity M is recorded as the first average permeability.

5. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: The second average permeability corresponding to the soil under the cave is calculated based on the parameter data and specifically includes the following process: Obtain the parameter data of the soil beneath the cave, including the proportion of muddy coarse sandstone, the proportion of broken and strongly weathered sandstone, the proportion of other filling materials, and the water content; Determine the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillings: the weights of muddy coarse sandstone, broken blocky strongly weathered sandstone, and other fillings are K4, K5, and K6 respectively; The second porosity M2 is obtained according to the correlation formula, which is as follows: Among them, Aj, Ak, and Al are the proportion of muddy coarse sandstone, the proportion of broken and strongly weathered sandstone, and the proportion of other filling materials, respectively; V2 is the total volume of the soil sampled below the cave; G is a constant coefficient, which is determined according to the total volume of the soil sampled below the cave V2. The larger V2 is, the larger G is. By calculating the proportion of water content to the total amount of soil below the cave, the average water density μ is obtained. The second average permeability X is obtained by correlating the average porosity M2 and the average water density μ. The correlation formula is: Where β is the permeability parameter, 0.25≤β≤0.

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6. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: The slurry is prepared according to the first average permeability and the second average permeability, and the process includes: Dividing the index interval according to the first average permeability and the second average permeability; If the average permeability is in the first index interval, the first slurry is determined as follows: cement accounts for 30%, water accounts for 20%, fly ash accounts for 30%, chelating agent accounts for 5%, clay accounts for 2%, fly ash accounts for 5%, and diatomaceous earth accounts for 8%; If the average permeability is in the second index interval, the second slurry is determined as follows: cement accounts for 20%, water accounts for 15%, fly ash accounts for 45%, chelating agent accounts for 8%, clay accounts for 4%, fly ash accounts for 3%, and diatomaceous earth accounts for 5%; If the average permeability is in the third index interval, the third slurry is determined: cement accounts for 27%, water accounts for 10%, fly ash accounts for 43%, chelating agent accounts for 10%, clay accounts for 5%, fly ash accounts for 3%, and diatomaceous earth accounts for 2%.

7. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: The double liquid grouting treatment construction method is used for grouting.

8. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 1, characterized in that: Before drilling holes according to the measured positions and forming pile holes, the pile foundation points are explored and the geological conditions at the surveyed locations are analyzed. With relatively complete geological data, early preparations for construction are made. In addition to the basic construction preparations of three connections and one leveling, sufficient soil, stone slabs required for backfilling, and steel casings are prepared.

9. A double-liquid grouting treatment construction method for a filling type large cave pile foundation according to claim 7, characterized in that: During grouting, when it is about 1m close to the cave roof, increase the mud specific gravity, impact with a small stroke, gradually penetrate the roof, and strengthen the monitoring of the mud surface changes in the hole. When the mud surface in the hole drops significantly, immediately lift the hammer, replenish mud in time, backfill clay, stone and bagged cement, and stop for a preset time. During the stop period, if the mud in the hole continues to drop, replenish mud and backfill the mixture at any time. After the mud in the hole stabilizes, continue to punch the hole, use a small stroke to impact and drop the mixture, so that it squeezes into the cave and blocks the cave channel. During the impact process, the mud in the hole will drop many times. Each time the mud drops, lift the hammer in time, replenish mud and backfill clay and stone, and stop punching for one day, and continue punching after it stabilizes. Repeat this cycle until the pile hole no longer leaks slurry and passes through the cave.

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