Soft rock tunnel backfill area mass concrete pouring method

Abstract

The invention discloses a mass concrete pouring method for a soft rock tunnel backfill area, and relates to the technical field of soft rock tunnel construction.The mass concrete pouring method for the soft rock tunnel backfill area comprises the steps that the soft rock tunnel backfill area is subjected to stabilizing treatment, and a reinforcing area is formed; the soft rock interface in the reinforcing area is subjected to roughening treatment, and a to-be-poured surface is formed; dividing a plurality of continuous pouring units on the to-be-poured surface according to the spiral path; and concrete is poured into the multiple pouring units in a layered mode in sequence, and large-volume concrete pouring construction of the soft rock tunnel backfill area is completed. The reinforcing area is formed through stabilizing treatment, the soft rock interface is subjected to targeted roughening treatment, concrete is poured in a layered mode through a spiral path, the bonding strength of the soft rock and concrete interface is improved, and the long-term stability of the tunnel structure is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soft rock tunnel construction, in particular to a large-volume concrete pouring method for soft rock tunnel backfill area. BACKGROUND

[0002] In the prior art, the large-volume concrete pouring of soft rock tunnel backfill area faces the problems of insufficient interfacial bonding strength and structural stability hazards.

[0003] When the traditional method adopts horizontal or inclined layered pouring, the interface between soft rock and concrete is not fully treated, resulting in weak bonding between the two. At the same time, the continuous deformation of soft rock under the load of concrete is not effectively controlled, which easily leads to stress concentration and structural cracking. For example, after a conventional layered pouring is adopted in a certain tunnel project, the interface between concrete and soft rock appears to be peeled off, and the lining structure is deformed in local areas due to stress redistribution. SUMMARY

[0004] The main purpose of the present application is to provide a large-volume concrete pouring method for soft rock tunnel backfill area, aiming to improve the interfacial bonding strength between soft rock and concrete and enhance the long-term stability of the tunnel structure.

[0005] To achieve the above-mentioned purpose, the large-volume concrete pouring method for soft rock tunnel backfill area provided by the present application comprises:

[0006] Stabilizing the soft rock tunnel backfill area to form a reinforced area;

[0007] Roughening the soft rock interface in the reinforced area to form a pouring surface;

[0008] Dividing a plurality of continuous pouring units on the pouring surface according to a spiral path;

[0009] Pouring concrete into the plurality of pouring units in layers and sequentially, to complete the large-volume concrete pouring construction of the soft rock tunnel backfill area.

[0010] In an embodiment, the step of roughening the soft rock interface in the reinforced area to form a pouring surface comprises:

[0011] Hardness testing of the soft rock interface in the reinforced area to obtain hardness distribution;

[0012] According to the hardness distribution, the soft rock interface is divided into a plurality of different treatment areas;

[0013] Roughening the soft rock interface in the plurality of different treatment areas to form the pouring surface.

[0014] In an embodiment, the step of dividing the soft rock interface into a plurality of different processing regions according to the hardness distribution includes:

[0015] dividing a region in the soft rock interface satisfying a first hardness range value into a first sub-processing region;

[0016] dividing a region in the soft rock interface satisfying a second hardness range value into a second sub-processing region;

[0017] dividing a region in the soft rock interface satisfying a third hardness range value into a third sub-processing region;

[0018] wherein the first hardness range value is greater than the second hardness range value, and the second hardness range value is greater than the third hardness range value.

[0019] In an embodiment, the step of roughening the soft rock interface in a plurality of different processing regions to form the to-be-poured surface includes:

[0020] roughening the surface of the soft rock interface corresponding to the first sub-processing region at a first chiseling depth;

[0021] washing the surface of the soft rock interface corresponding to the second sub-processing region and roughening the surface of the soft rock interface corresponding to the second sub-processing region at a second chiseling depth;

[0022] cleaning and flattening the surface of the soft rock interface corresponding to the third sub-processing region to form the to-be-poured surface;

[0023] wherein the first chiseling depth is greater than the second chiseling depth.

[0024] In an embodiment, the step of dividing a plurality of continuous pouring units on the to-be-poured surface according to a spiral path includes:

[0025] setting a spiral line extending outward from the geometric center of the to-be-poured surface on the to-be-poured surface to form the spiral path.

[0026] In an embodiment, the pitch of the spiral line located in the first sub-processing region is greater than the pitch of the spiral line located in the second sub-processing region, and the pitch of the spiral line located in the second sub-processing region is greater than the pitch of the spiral line located in the third sub-processing region.

[0027] In an embodiment, the step of completing the mass concrete pouring construction of the soft rock tunnel backfill area includes:

[0028] pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete;

[0029] pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete;

[0030] pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete;

[0031] In an embodiment, the step of pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete further comprises:

[0032] before pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete, curing the bottom layer concrete by isolating and protecting the bottom layer concrete and temperature compensation;

[0033] before pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete, curing the bottom layer concrete by isolating and protecting the bottom layer concrete and temperature compensation;

[0034] before pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete, curing the bottom layer concrete by isolating and protecting the bottom layer concrete and temperature compensation.

[0035] In an embodiment, the method of pouring mass concrete to the soft rock tunnel backfill area further comprises, before the step of pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete:

[0036] preheating the surface of the soft rock interface corresponding to the plurality of pouring units.

[0037] In an embodiment, the step of pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete further comprises:

[0038] monitoring the displacement, strain and stress change of the soft rock interface corresponding to the plurality of pouring units to obtain monitoring results;

[0039] pouring concrete to the plurality of pouring units according to the spiral path to form bottom layer concrete;

[0040] The technical scheme of the application forms a reinforced area through stabilization treatment, carries out targeted roughening treatment on the soft rock interface, and adopts a spiral path to pour the concrete in layers, thereby solving the technical problems of insufficient interface bonding strength in the traditional method and the inability to adapt to the deformation characteristics of soft rock. Gradient bonding of the soft rock and the concrete interface is achieved, and the risk of local peeling is avoided. The spiral pouring path reduces the probability of cold joint formation, so that the mass concrete structure can still maintain overall stability under the condition of soft rock deformation. The layered interval pouring is combined with maintenance measures to effectively control the generation of temperature cracks. The interface bonding strength of the soft rock and the concrete is improved, and the long-term stability of the tunnel structure is improved. BRIEF DESCRIPTION OF DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description only constitute some embodiments of the present application, and for those skilled in the art, other drawings can also be obtained from the structures shown in the drawings without creative labor.

[0042] Figure 1 The flowchart of an embodiment of the soft rock tunnel backfill area mass concrete pouring method provided by the present application.

[0043] The implementation, functional characteristics and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. DETAILED DESCRIPTION

[0044] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments only constitute some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0045] It should be noted that if the present application embodiments involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement condition, etc. between the components in a certain posture, and if the certain posture changes, the directional indications will also change accordingly.

[0046] In addition, if the description of "first", "second" and the like is involved in the embodiments of the present application, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes are included, for example, "A and / or B" includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the realization of the ordinary skilled in the art, when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor in the protection scope required by the present application.

[0047] The traditional concrete pouring technology has many deficiencies in the construction of soft rock tunnel backfill area. First, the roughening treatment of the interface between soft rock and concrete is often ignored during construction, resulting in insufficient bonding strength between them and easy interface peeling. Second, the traditional mass concrete pouring method adopts horizontal layering or inclined layering method, which has obvious limitations in the special geological environment of soft rock tunnel backfill area and cannot effectively adapt to the deformation characteristics of soft rock. More importantly, soft rock will undergo continuous creep deformation when bearing mass concrete load, which will significantly affect the stress distribution of concrete and the overall stability of the structure. The existing construction method often fails to fully consider the dynamic influence of soft rock deformation on the stress state of concrete, resulting in potential risks in the long-term stability of the structure after pouring. In addition, the traditional method lacks targeted treatment measures for the hardness difference of the soft rock interface, making it difficult to ensure the bonding quality of the interface between concrete and soft rock with different hardness. In view of the above problems, the existing technology needs to be improved.

[0048] To solve the technical problem, the present application provides a soft rock tunnel backfill area mass concrete pouring method.

[0049] Please refer to Figure 1 In an embodiment of the present application, the soft rock tunnel backfill area mass concrete pouring method comprises:

[0050] Step S10, stabilizing treatment is performed on the soft rock tunnel backfill area to form a reinforced area;

[0051] Step S20, roughening treatment is performed on the soft rock interface in the reinforced area to form a pouring surface;

[0052] Step S30, a plurality of continuous pouring units are divided on the pouring surface according to a spiral path;

[0053] In step S40, the soft rock tunnel backfill area is filled with concrete by layering and pouring the concrete into the multiple pouring units in sequence.

[0054] It should be noted that the stabilization treatment refers to a process of improving the bearing capacity of soft rock by grouting or anchoring means, and can be realized by cement-water glass double liquid grouting, and a whole reinforcing structure is formed by filling the rock mass cracks. The roughening treatment refers to a graded surface treatment according to the hardness difference of the soft rock, for example, mechanical chiseling is used for high hardness areas, and flushing and leveling are performed for low hardness areas, so that a gradient rough interface is formed to enhance the bonding force. The spiral path refers to a continuous curve trajectory extending outward from the geometric center, for example, an Archimedes spiral is used to divide the pouring units, and the continuity of the path reduces the risk of construction cold joints. The layered pouring refers to filling the concrete layer by layer in the spiral order, for example, the concrete is poured in three times for the bottom layer, the middle layer and the surface layer, and the whole structure is formed by layering and stacking.

[0055] More specifically, the soft rock is first reinforced by grouting to form a stable bearing layer, and the rock mass creep risk is eliminated. Then, according to the hardness detection results, the interface of the reinforced area is treated differently: deep grooves are chiseled in high hardness areas, shallow chiseling is performed after flushing in medium hardness areas, and a smooth surface is formed after cleaning the dregs in low hardness areas. Then, the spiral line is used to divide the pouring surface into continuous units, and the bottom layer of concrete is poured outward from the center. After initial setting, the middle layer is poured along the same path, and finally the surface layer is covered. In this process, the continuity of the spiral path allows the concrete load to be uniformly transmitted to the soft rock, and the interval period of layered pouring can be used to implement maintenance measures to control the hydration heat.

[0056] Compared with the prior art, the traditional method uses a fixed depth interface treatment, and does not consider the bonding force attenuation problem caused by the hardness difference of the soft rock. The present scheme matches the interface roughness with the rock mass strength by graded treatment. The linear joints formed by the existing horizontal layered pouring are prone to stress concentration, while the curved characteristics of the spiral path continuously change the load transmission direction, effectively dispersing the stress caused by the deformation of the soft rock.

[0057] In the technical scheme provided by the present application, the reinforced area is formed by stabilization treatment, the soft rock interface is treated by targeted roughening, and the concrete is poured by layered pouring with a spiral path, which solves the technical problems of insufficient interface bonding strength and inability to adapt to the deformation characteristics of the soft rock in the traditional method. Gradient bonding between the soft rock and the concrete interface is achieved, and the risk of local peeling is avoided. The spiral pouring path reduces the probability of cold joint formation, so that the mass concrete structure can still maintain overall stability under the condition of soft rock deformation. The interval pouring of layers is combined with maintenance measures to effectively control the generation of temperature cracks. The interface bonding strength between the soft rock and the concrete is improved, and the long-term stability of the tunnel structure is improved.

[0058] In the embodiments of the present application, the roughening treatment of the soft rock interface in the reinforced area includes the following steps:

[0059] In step S21, the hardness of the soft rock interface in the reinforced area is tested to obtain the hardness distribution.

[0060] In step S22, the soft rock interface is divided into different treatment areas according to the hardness distribution.

[0061] In step S23, the soft rock interface in the different treatment areas is roughened to form the pouring surface.

[0062] It should be noted that the hardness test refers to measuring the mechanical properties of the soft rock interface at different positions to evaluate its bearing capacity. Specifically, a rebound hammer or an indentation tester can be used for multi-point sampling to obtain hardness distribution data. The treatment area division refers to dividing the soft rock interface into sub-areas with different mechanical properties according to the hardness test results. Specifically, different hardness threshold ranges can be set, for example, areas with hardness higher than a certain value are classified as high hardness areas, and areas with hardness lower than a certain value are classified as low hardness areas. Roughening treatment refers to changing the surface morphology of the soft rock interface through physical or chemical means to enhance its bonding force with concrete. Specifically, methods such as chiseling, sandblasting, or high-pressure water jetting can be used to achieve this.

[0063] More specifically, in the implementation process, first, the rebound hammer is used to detect the hardness of the reinforced soft rock interface at multiple points to generate a hardness distribution map. According to the test results, the interface is divided into three hardness levels of treatment areas: high, medium, and low. For example, areas with hardness values above 50 MPa are classified as the first treatment area, areas with hardness values between 30 and 50 MPa are classified as the second treatment area, and areas with hardness values below 30 MPa are classified as the third treatment area. Then, different roughening processes are adopted for different areas: deep chiseling is used in high hardness areas to form concave-convex textures, shallow chiseling combined with surface washing is used in medium hardness areas, and low hardness areas are cleaned and leveled. In this way, the interface treatment intensity is matched with the actual bearing capacity of the soft rock.

[0064] Compared with the prior art, the traditional method usually performs uniform surface treatment on the soft rock interface without considering the hardness difference of different areas. For example, excessive chiseling in low hardness areas may cause rock fragmentation, while insufficient treatment in high hardness areas cannot form an effective bonding surface. The present scheme avoids secondary damage to the soft rock structure through hardness grading and differential treatment, and ensures the effectiveness of the interface treatment. It solves the problem of insufficient concrete bonding force caused by uneven hardness of the soft rock interface. Through zoned treatment, the interface roughness is ensured while the integrity of the soft rock structure is maintained, reducing the risk of structural cracking caused by local stress concentration after pouring, and improving the cooperative bearing capacity of the concrete and the soft rock interface.

[0065] In the embodiments of the present application, the step of dividing the soft rock interface into a plurality of different processing regions according to the hardness distribution includes:

[0066] Step S221, dividing the region in the soft rock interface that meets the first hardness range value into a first sub-processing region;

[0067] Step S222, dividing the region in the soft rock interface that meets the second hardness range value into a second sub-processing region;

[0068] Step S223, dividing the region in the soft rock interface that meets the third hardness range value into a third sub-processing region;

[0069] Wherein, the first hardness range value is greater than the second hardness range value, and the second hardness range value is greater than the third hardness range value.

[0070] It should be noted that the first hardness range value refers to a higher hardness interval determined by hardness testing, which can be measured by a Shore hardness tester, for example, the hardness value can be set to 60-80HS. This range is used to identify the region of the soft rock interface with relatively stable structure, so as to facilitate subsequent processing with corresponding strength. Among them, the second hardness range value refers to the medium hardness interval, which can be set to 40-60HS, for example. This range is used to identify the region with potential deformation risk, and the interface processing measures of medium strength need to be taken. Among them, the third hardness range value refers to the lower hardness interval, which can be set to 20-40HS, for example. This range is used to identify the region with loose structure or easy deformation, which needs to be flattened to reduce the risk of stress concentration.

[0071] More specifically, after completing the hardness test of the soft rock interface, the interface is divided into three regions of high, medium and low stability levels by dividing the three hardness intervals. For example, the first sub-processing region corresponds to the high-hardness rock layer of the pressure-bearing part such as the tunnel vault, the second sub-processing region corresponds to the medium-hardness rock layer of the sidewall, and the third sub-processing region corresponds to the loose rock layer at the bottom. Corresponding chiseling, flushing or flattening treatment is carried out for different regions, so that the interface bonding strength matches the rock mass bearing capacity when the concrete is poured. Through this division method, local stress imbalance caused by uniform treatment can be avoided, and structural damage caused by excessive chiseling in weak areas can be reduced.

[0072] The scheme classifies the interface treatment depth and intensity and the actual bearing capacity of the rock mass by hardness classification, for example, deep chiseling and roughening are used in high hardness areas to enhance the bonding force, and the low hardness areas are flattened to avoid structural disturbance, so that the interface bonding strength is improved while maintaining the stability of soft rock. The problem of uneven distribution of concrete bonding force caused by hardness difference of soft rock interface is solved, and the interface treatment method of different hardness areas is adapted to the mechanical properties of the rock mass. Thus, the risk of cracks caused by local bonding failure after concrete pouring can be effectively reduced, and the non-uniform stress influence of soft rock deformation on the concrete structure is avoided, and the cooperative bearing capacity of the soft rock interface of the mass concrete is improved.

[0073] In the embodiment of the present application, the roughening treatment is performed on the soft rock interface in a plurality of different treatment areas, and the step of forming the surface to be poured includes:

[0074] Step S231, the surface of the soft rock interface corresponding to the first sub-treatment area is chiseled with a first chiseling depth;

[0075] Step S232, the surface of the soft rock interface corresponding to the second sub-treatment area is washed and chiseled with a second chiseling depth;

[0076] Step S233, the surface of the soft rock interface corresponding to the third sub-treatment area is cleaned and flattened to form the surface to be poured;

[0077] Wherein, the first chiseling depth is greater than the second chiseling depth.

[0078] It should be noted that the first chiseling depth refers to the depth of mechanical marking on the surface of the high hardness area, which can be realized by impact drill or rock drill, and the mechanical interlocking force between the concrete and the rock layer is enhanced by forming concave-convex texture. The second chiseling depth refers to the depth of shallow marking on the surface of the medium hardness area, which can be realized by high-pressure water jet combined with light chisel, and an effective bonding surface is formed under the premise of avoiding rock fragmentation. The cleaning and flattening of the third sub-treatment area refers to the removal of loose materials and contour modification on the surface of the low hardness area, which can be realized by pneumatic slag cleaning tool combined with scraper, and the flatness of the pouring contact surface is ensured by eliminating surface defects.

[0079] More specifically, the deep chiseling process is adopted in the first sub-processing area with high hardness to increase the contact area and interlocking effect by forming deep grooves; the surface flushing is performed first to remove floating dust in the second sub-processing area with medium hardness, and then the shallow chiseling is implemented to avoid damaging the rock structure; the surface cleaning is mainly performed in the third sub-processing area with low hardness to form a uniform support surface by removing loose particles and trimming concave and convex parts. The process intensity is adjusted according to the hardness gradient of the rock stratum in different processing modes, which not only ensures the interface bonding strength but also avoids damage to the rock mass caused by excessive processing.

[0080] The present scheme realizes the dynamic adaptation of the interface processing intensity and the bearing capacity of the rock mass by hardness grading processing, strengthens the interface bonding in the hard rock area, reduces the processing intensity in the soft rock area to prevent structural damage, effectively solves the problem of insufficient intensity matching in the interface processing of alternating soft and hard rock strata, improves the bonding force of the concrete and the rock mass while avoiding structural damage in the soft area, reduces the stress concentration phenomenon caused by improper interface processing, and ensures the overall stability of the mass concrete structure.

[0081] In the embodiment of the present application, the step of dividing a plurality of continuous pouring units on the surface to be poured according to a spiral path comprises:

[0082] Step S31, a spiral line extending outward from the geometric center of the surface to be poured is set on the surface to be poured to form the spiral path.

[0083] It should be noted that the geometric center refers to the symmetric center point of the plane shape of the surface to be poured, which can be realized by measuring the boundary coordinates of the surface to be poured and calculating the geometric center point, for example, using a total station or a three-dimensional laser scanning device for positioning. The spiral path refers to a spiral trajectory continuously extending outward from the geometric center as the starting point, which can be realized by presetting a marker point or dynamically adjusting the movement trajectory of the pouring equipment, for example, by controlling the movement path of the concrete pump truck to generate a spiral line.

[0084] More specifically, after determining the geometric center on the surface to be poured, the spiral line is drawn outward from the center as the starting point according to the preset rotation direction and pitch. The extension range of the spiral line covers the entire surface to be poured, thereby dividing the surface to be poured into a plurality of continuous annular pouring units. The boundary of each pouring unit is defined by the adjacent two tracks of the spiral line, and the pouring sequence is pushed out layer by layer from the center outward along the spiral path. For example, the pitch of the spiral line can be adjusted according to the hardness difference of the soft rock interface, the pitch can be appropriately increased in the area with higher hardness, and the pitch can be reduced in the area with lower hardness.

[0085] Compared with the prior art, the traditional method divides the pouring unit by horizontal layering or inclined layering, which is easy to cause the concentrated application of the concrete load to the local area of the soft rock, and aggravate the risk of interface deformation. The division mode of the spiral path makes the concrete load uniformly diffuse along the spiral direction, avoids the stress mutation, and the continuous characteristics of the spiral line reduce the number of construction joints and the probability of the weak point of the interface combination.

[0086] The application realizes the gradual transmission of the load in the concrete pouring process, effectively alleviates the negative influence of the soft rock deformation on the concrete structure. The division mode of the spiral path makes the combination strength of the concrete and the soft rock interface more uniform, reduces the crack risk caused by local stress concentration, and improves the integrity and long-term stability of the mass concrete structure.

[0087] In the embodiment of the application, the pitch of the spiral line located in the first sub-processing area is greater than the pitch of the spiral line located in the second sub-processing area, and the pitch of the spiral line located in the second sub-processing area is greater than the pitch of the spiral line located in the third sub-processing area.

[0088] It should be noted that the pitch of the spiral line refers to the axial distance between adjacent two turns of the spiral line, which can be realized by laser lofting combined with a mechanical positioning device, and the division density of the concrete pouring unit is controlled by adjusting the pitch parameter. The first sub-processing area, the second sub-processing area and the third sub-processing area refer to different processing areas divided according to the test results of the soft rock interface hardness, which can be realized by geological radar scanning combined with hardness meter measurement, and the area with higher hardness value needs more intensive pouring unit division.

[0089] More specifically, when the spiral path is set on the surface to be poured, the pitch parameter is adjusted according to the pre-divided soft rock interface processing area. For the first sub-processing area with high hardness, a larger pitch is used to divide the pouring unit to reduce the concrete flow resistance; for the second sub-processing area with medium hardness, a medium pitch is used to balance the structure strength and construction efficiency; for the third sub-processing area with low hardness, a smaller pitch is used to increase the pouring unit density to compensate for the bearing capacity of the soft rock. This gradient change of the pitch setting mode can make the concrete pouring path match the mechanical properties of the soft rock.

[0090] The scheme automatically adjusts the division density of the pouring unit according to the corresponding relationship between the pitch and the hardness of the soft rock, effectively solves the technical defects that the traditional method is prone to stress concentration in the alternating soft and hard stratum, realizes the dynamic adaptation of the pouring path parameters to the geological conditions, ensures the bonding strength of the soft rock and the concrete interface, and avoids the risk of concrete cracking caused by the deformation of the soft rock. Through the gradient change of the pitch, the structural stress distribution state is optimized while the construction efficiency is ensured, and the construction quality of the mass concrete pouring under the complex geological conditions is effectively improved.

[0091] In the embodiment of the application, the step of completing the mass concrete pouring construction of the soft rock tunnel backfill area includes:

[0092] Step S41, pouring concrete into a plurality of pouring units according to the spiral path to form a bottom layer of concrete;

[0093] Step S42, pouring concrete on the bottom layer of concrete according to the spiral path to form a middle layer of concrete;

[0094] Step S43, pouring concrete on the middle layer of concrete according to the spiral path to form a surface layer of concrete, and completing the mass concrete pouring construction of the soft rock tunnel backfill area.

[0095] It should be noted that the spiral path refers to a continuous curved trajectory extending outward from the geometric center as the starting point, and can be realized by using a segmented spiral line or a gradually changing pitch spiral line. The path reduces the interface shear stress concentration by controlling the direction of concrete flow. The layered pouring refers to the construction of the concrete into a bottom layer, a middle layer and a surface layer in sequence, and can be realized by using the way of stacking after each layer is solidified. This way reduces the risk of temperature cracking by releasing hydration heat in stages. The bottom layer of concrete refers to the first layer of concrete directly contacting the soft rock interface, and can be realized by using low hydration heat proportioning materials. Its role is to preliminarily fix the interface bonding state and provide a supporting foundation for subsequent pouring. The middle layer of concrete refers to the transition layer between the bottom layer and the surface layer, and can be realized by using concrete materials with medium fluidity. This layer coordinates the deformation difference between the upper and lower layers by uniformly transmitting the load. The surface layer of concrete refers to the outermost closed layer, and can be realized by using high density proportioning materials. Its role is to form a complete protective surface to prevent external environmental erosion.

[0096] More specifically, after the spiral path is divided on the surface to be poured, the continuous pouring of the bottom layer concrete is first completed along the path. After the bottom layer concrete solidifies, the secondary pouring in the middle layer area is carried out along the same spiral path, and at this time the bottom layer has formed a stable support. After the middle layer reaches the predetermined strength, the closed pouring of the surface layer concrete is finally completed along the spiral path. The pouring direction of each layer remains consistent to avoid internal stress differences caused by path deviation. During the pouring process, the continuity of the spiral path ensures the uniformity of the concrete flow, and the layered structure effectively disperses the stress transmission caused by the deformation of soft rock.

[0097] Compared with the prior art, the traditional horizontal layered pouring is prone to interlayer dislocation when the soft rock deforms, while the layered pouring of the spiral path forms a circumferential stress compensation mechanism for each layer of concrete through the continuity of the path. The temperature gradient formed by single pouring in the prior art can cause the interface bonding force to decrease, and the layered structure of the present scheme enables each layer of concrete to independently complete the main hydration reaction, thereby reducing the influence of overall temperature rise on the soft rock interface. The multi-level progressive combination of the soft rock interface and the concrete is realized, and the interlayer peeling phenomenon caused by the continuous deformation of the soft rock is effectively inhibited. The layered pouring of the spiral path makes the internal stress distribution of the concrete more in line with the deformation characteristics of the soft rock, avoiding the end stress concentration problem caused by the traditional straight-line path pouring. The stepwise strength growth formed by phased construction makes the overall stiffness of the structure match the deformation rate of the soft rock, significantly improving the long-term stability of the mass concrete structure.

[0098] In the embodiments of the present application, the layered and sequentially pouring concrete into a plurality of pouring units to complete the mass concrete pouring construction of the soft rock tunnel backfill area further includes:

[0099] Step S401, before pouring concrete on the bottom layer concrete according to the spiral path to form middle layer concrete, the bottom layer concrete is isolated and protected and temperature compensated to cure the bottom layer concrete;

[0100] Step S402, before pouring concrete on the middle layer concrete according to the spiral path to form surface layer concrete, the middle layer concrete is ventilated and humidity adjusted to cure the middle layer concrete;

[0101] Step S403, after pouring concrete on the middle layer concrete according to the spiral path to form surface layer concrete, the surface layer concrete is covered and moisturized and temperature controlled to cure the surface layer concrete.

[0102] It should be noted that the isolation protection refers to isolating the interference of the external environment on the concrete through a physical barrier, which can be achieved by laying waterproof cloth or plastic film to prevent water evaporation and pollutant contact. Temperature compensation refers to actively adjusting the concrete temperature to maintain suitable curing conditions, which can be achieved by using an electric blanket or a circulating water system to reduce cracks caused by temperature stress. Ventilation and humidity regulation refers to controlling the surface humidity of the concrete through air circulation, which can be achieved by using an axial flow fan or an atomizing humidification device to balance the water distribution during hardening. Covering and moisturizing refers to keeping the surface of the concrete moist by sealing materials, which can be achieved by using wet burlap or moisturizing film to delay water loss. Temperature control refers to maintaining the concrete in a stable temperature range, which can be achieved by using a constant temperature curing shed or a temperature sensor linked heating device to avoid shrinkage deformation caused by temperature difference.

[0103] More specifically, after the bottom layer of concrete is poured, waterproof cloth is laid on the surface to isolate the external environment, and an electric blanket is used to uniformly heat and maintain the concrete temperature, so that the initial hardening of the concrete is completed under constant conditions. Before pouring the middle layer of concrete, an axial flow fan is used to ventilate the surface of the bottom layer, and an atomizing nozzle is used to adjust the air humidity to ensure that the interface between the middle layer of concrete and the bottom layer is in a suitable humidity environment. After pouring the surface layer of concrete, wet burlap is covered and a constant temperature curing shed is built, the temperature change is continuously monitored and the heating power is adjusted, so that the surface layer of concrete slowly hardens in a humid and constant temperature environment. By implementing differentiated curing measures in stages, the hardening process of each layer of concrete is optimized, reducing the accumulation of internal stress caused by environmental fluctuations.

[0104] The present application can adapt to the concrete curing needs in the complex environment of the soft rock tunnel backfill area by implementing isolation protection, temperature compensation, ventilation regulation and covering and moisturizing in layers, avoiding the decrease of interlayer bonding strength caused by sudden temperature change or humidity imbalance. The structural stability problem caused by the interaction between soft rock deformation and concrete hardening process is effectively solved. The isolation protection and temperature compensation of the bottom layer of concrete reduce the early shrinkage cracks, the ventilation and humidity regulation of the middle layer of concrete optimize the bonding performance of the interlayer interface, and the covering and moisturizing and temperature control of the surface layer of concrete inhibit the surface cracking. The synergistic effect of the curing measures of each layer improves the compactness and anti-deformation ability of the overall structure of the concrete.

[0105] In the embodiment of the present application, before the step of pouring concrete into a plurality of pouring units according to the spiral path to form a bottom layer of concrete, the mass concrete pouring method for the soft rock tunnel backfill area further comprises:

[0106] Step S400, preheating the surface of the soft rock interface corresponding to a plurality of pouring units.

[0107] It should be noted that the preheating treatment refers to the process of temperature regulation of the soft rock interface by an external heat source, which can be realized by using an electric blanket, steam injection or a hot air circulation system, and the temperature difference between the concrete and the soft rock is reduced by increasing the interface temperature. The role of this step is to reduce the shrinkage stress caused by the temperature gradient during the solidification of the concrete, and to promote the development of the early bond strength of the concrete and the soft rock interface.

[0108] More specifically, when the preheating treatment is implemented, first, the corresponding preheating temperature is determined according to the type of the treatment area divided by the soft rock interface. For example, for the first sub-treatment area with high hardness, a higher preheating temperature can be used to enhance the interface activity; for the second sub-treatment area with low hardness, a medium preheating temperature is used to avoid damage to the soft rock structure; for the third sub-treatment area that needs to be leveled, a basic preheating temperature is used to maintain the stability of the interface. During the preheating process, temperature sensors are arranged at different positions of the interface to monitor the temperature distribution in real time, and the temperature uniformity control is realized by adjusting the power of the heat source.

[0109] In some embodiments, the preheating treatment can use a staged heating method, the initial stage is heated to the target temperature at a rate of not more than 10℃ per hour, the holding stage lasts for 2-4 hours to make the heat fully conduct, and the cooling stage uses natural cooling to control the temperature difference between the interface and the concrete to be poured within 15℃. After preheating, the condensate or impurities remaining on the surface of the interface need to be cleaned again.

[0110] The present scheme effectively reduces the stress concentration phenomenon of the interface caused by temperature mutation through interface preheating treatment, and enhances the hydration reaction activity of the soft rock surface and the concrete through temperature regulation, avoiding the loss of bond strength caused by temperature difference. The problem of the decrease of the bonding strength of the soft rock interface and the concrete caused by the temperature difference is solved, the micro-cracks caused by the temperature stress are reduced, the integrity and durability of the mass concrete structure are improved, and especially in the soft rock continuous deformation environment, the shear resistance of the interface area is enhanced.

[0111] In the embodiments of the present application, the step of completing the mass concrete pouring construction of the soft rock tunnel backfill area includes:

[0112] Step S410, monitoring the displacement, strain and stress change of the soft rock interface corresponding to the plurality of pouring units to obtain the monitoring results;

[0113] Step S420, layering and sequentially pouring concrete into a plurality of pouring units, and adjusting the pouring condition of the concrete according to the monitoring results until the mass concrete pouring construction of the soft rock tunnel backfill area is completed.

[0114] It should be noted that the displacement amount refers to the spatial position change amount of the soft rock interface during the concrete pouring process, which can be measured in real time by a displacement sensor or a laser ranging device, and is used to judge the local deformation degree of the soft rock. The strain amount refers to the deformation degree of the soft rock interface after being stressed, which can be continuously monitored by using a strain gauge or an optical fiber sensor, and is used to evaluate the mechanical response of the soft rock and the concrete contact surface. The stress change condition refers to the dynamic change of the load distribution of the soft rock interface, which can be collected at multiple points by using a pressure sensor or a stress meter, and is used to analyze the influence of concrete pouring on the load transfer of the soft rock. The monitoring result refers to a comprehensive data set formed by collecting the above parameters, which can be analyzed in real time by using a data acquisition system and an algorithm model, and is used to guide the process adjustment of concrete pouring. Adjusting the pouring condition of the concrete refers to dynamically controlling the pouring speed, the layer thickness or the pouring sequence according to the monitoring data, which can be realized by adjusting the parameters of the pumping equipment or the construction path, and is used to balance the interaction between the soft rock deformation and the concrete solidification process.

[0115] More specifically, during the layered pouring process, a displacement sensor is arranged at a key position of the soft rock interface to collect rock mass displacement data in real time; a strain gauge is distributed along the interface to monitor the local deformation trend; and a pressure sensor is embedded in the soft rock and concrete contact layer to record the stress distribution change. The monitoring data is transmitted wirelessly to a control terminal and an adjustment instruction of the pouring parameters is generated after algorithm processing. For example, when the displacement amount of a certain area exceeds the threshold value, the pouring speed of the area is automatically reduced; when the stress change curve appears abnormal fluctuation, the pouring is immediately paused and support reinforcement is started. Through the dynamic feedback mechanism, the concrete pouring and the soft rock deformation are kept coordinated to avoid interface cracking or structure instability caused by stress concentration.

[0116] Compared with the prior art, the traditional method only relies on experience to judge the pouring process, and lacks quantitative monitoring of the dynamic response of the soft rock. In the prior art, the real-time correlation between the pouring parameters and the mechanical behavior of the rock mass is not established, and the risks brought by the continuous deformation of the soft rock cannot be responded in time. The present scheme realizes the improvement of the controllability of the construction process through multi-parameter synchronous monitoring and intelligent regulation, and effectively solves the problem of decreased bonding strength caused by the asynchronization of soft rock deformation and concrete solidification.

[0117] Through the above technical scheme, the present application can capture the mechanical state change of the soft rock and the concrete interface in real time, accurately control the load transfer path in the pouring process, and avoid abnormal distribution of concrete stress caused by soft rock creep. Through the data-driven dynamic adjustment mechanism, the cooperative bearing capacity of the mass concrete and the soft rock tunnel is significantly improved, the overall stability of the structure in long-term use is ensured, and the technical defects of insufficient interface bonding strength and structure hidden danger accumulation in the traditional construction method are solved.

[0118] Based on the above embodiments, a specific embodiment is shown here for ease of understanding:

[0119] The technical solution of the present application includes three main stages:

[0120] The first stage is the soft rock foundation pretreatment stage, mainly completing the stabilization treatment of the soft rock surface and the preparation work for pouring the foundation; the second stage is the layered progressive pouring stage, using innovative pouring process to realize the orderly construction of mass concrete; the third stage is the dynamic maintenance and stress regulation stage, through special maintenance method to ensure the quality of concrete and structural stability.

[0121] First stage: soft rock foundation pretreatment stage:

[0122] Soft rock surface stabilization treatment steps:

[0123] Before pouring mass concrete in the soft rock tunnel backfill area, the soft rock surface needs to be stabilized first. Soft rock is prone to local deformation or damage when bearing the load of mass concrete due to its inherent low strength and easy weathering characteristics, so its bearing capacity and stability must be improved through special treatment methods.

[0124] In specific implementation, first, the soft rock surface is subjected to detailed geological survey to identify the weathering degree, fracture development and bearing capacity distribution of the soft rock. Then, a regional treatment method is used to take corresponding stabilization measures for soft rock in different regions. For soft rock regions with lighter weathering degree, surface cleaning and light reinforcement methods are used; for soft rock regions with heavier weathering degree, deep treatment is needed, including measures such as removing loose rock mass, filling cracks and strengthening support.

[0125] During the stabilization treatment of the soft rock surface, special attention is paid to the treatment of the soft rock structural surface. The structural surface in soft rock includes bedding surface, joint surface and fault surface, etc., which are often the weak link of soft rock stability. For bedding surface, its inclination and dip angle need to be evaluated for their impact on concrete pouring, when the bedding surface has a large dip angle, a stepped excavation method is needed to increase the contact area and friction; for joint surface, the fillings in the joint need to be cleaned, and whether filling reinforcement is needed is determined according to the joint opening and connectivity; for fault surface, due to its strong activity, special reinforcement measures need to be taken, such as setting anchor rods or grouting reinforcement.

[0126] Interface roughening pretreatment technology:

[0127] Progressive interface roughening treatment technology:

[0128] Traditional concrete pouring often ignores the roughening treatment of the interface between soft rock and concrete, resulting in insufficient bonding strength between the two. The present application innovatively proposes a progressive interface roughening treatment technology, which uses different degrees of roughening treatment methods according to the hardness distribution and structural characteristics of soft rock, forming a gradient change in interface roughness.

[0129] In specific implementation, first, the hardness of the soft rock surface is tested, and a hardness distribution map is drawn. Then, according to the hardness distribution, the soft rock surface is divided into different treatment areas. For areas with high hardness, mechanical chiseling is used to increase the surface roughness, with a chiseling depth of 5-10 mm and a chiseling pitch of 20-30 mm; for areas with medium hardness, high-pressure water washing combined with light chiseling is used, which can not only remove loose materials on the surface, but also moderately increase the surface roughness; for areas with low hardness, mainly cleaning and leveling methods are used to avoid excessive treatment that may cause the soft rock to further loosen.

[0130] The key to progressive interface roughening treatment is to form a continuous roughness gradient, so that the stress transfer between concrete and soft rock is more uniform. At the junction of different roughness areas, a transitional treatment method is used to avoid stress concentration caused by sudden changes in roughness. At the same time, during the roughening process, attention should be paid to protecting the overall structure of the soft rock to avoid affecting the overall stability due to improper local treatment.

[0131] Second stage: layered progressive pouring stage:

[0132] Spiral layered progressive pouring technology:

[0133] Traditional mass concrete pouring often uses horizontal layering or inclined layering methods, but in the special environment of soft rock tunnel backfill area, these methods have obvious limitations. The present application innovatively proposes a spiral layered progressive pouring technology, which combines the characteristics of soft rock geology and the spatial constraints of tunnel backfill area, and realizes the orderly pouring of concrete through a spiral pouring path.

[0134] The core idea of spiral layered progressive pouring technology is to divide the entire backfill area into multiple pouring units according to the spiral path, with the volume of each pouring unit controlled within a reasonable range, which can ensure the continuity of pouring and effectively control the temperature stress of concrete. In specific implementation, first, the spiral pouring path is designed according to the geometric shape of the backfill area and the geological conditions of soft rock. The starting point of the spiral path is usually set at the center of the backfill area, and then it expands outward according to the predetermined pitch and angle of rise.

[0135] In the spiral pouring process, the thickness of each layer is controlled between 0.3-0.5 meters, which can ensure the compactness of the concrete and effectively control the temperature change in the pouring process. The pouring time interval between adjacent two layers is adjusted according to the initial setting time of the concrete and the ambient temperature, and is generally controlled between 2-4 hours. The control of this time interval can ensure that the lower concrete has sufficient bearing capacity and ensure the effectiveness of the interlayer combination.

[0136] The design of the spiral pouring path also considers the unevenness of soft rock geology. In areas where the strength of soft rock is low, the pitch is appropriately reduced, and the number of pouring layers is increased to reduce the pressure of single-layer concrete on soft rock; in areas where the strength of soft rock is high, the pitch can be appropriately increased to improve the pouring efficiency. At the same time, special pouring techniques are used at the turning points and intersection points of the spiral path to ensure the continuity and integrity of the concrete.

[0137] Temperature stress control technology:

[0138] Temperature stress control during mass concrete pouring is a key factor to ensure project quality. In the soft rock tunnel backfill area, due to the poor thermal conductivity of soft rock, the dissipation of concrete hydration heat is limited, which easily leads to high internal temperature and harmful temperature stress.

[0139] The present application adopts a phased temperature control strategy, which divides the entire pouring process into three stages: heating period, constant temperature period and cooling period. Different temperature control measures are used in each stage. In the heating period, the pouring temperature of the concrete and the generation speed of the hydration heat are mainly controlled, which is realized by adjusting the concrete mix proportion and pouring speed; in the constant temperature period, the internal temperature of the concrete is mainly maintained stable by insulation measures to avoid excessive temperature gradient; in the cooling period, the cooling speed is mainly controlled to avoid tensile stress due to rapid cooling.

[0140] In specific implementation, before pouring the concrete, the soft rock surface is preheated to match the temperature with the pouring temperature of the concrete, reducing the temperature difference at the interface. During the pouring process, the concrete out-machine temperature and pouring speed are controlled to control the internal temperature rise rate of the concrete within a reasonable range. After the concrete pouring is completed, different insulation measures are used for different depths of concrete by layer insulation.

[0141] Third stage: dynamic maintenance and stress regulation stage:

[0142] Dynamic stress monitoring and regulation technology:

[0143] Dynamic stress regulation technology based on soft rock deformation:

[0144] Soft rock will undergo continuous deformation when bearing large volume of concrete load, which will affect the stress distribution and structural stability of the concrete. Traditional construction methods often ignore the influence of soft rock deformation on the stress state of concrete, resulting in potential risks to the long-term stability of the structure. The invention innovatively proposes a dynamic stress regulation technology based on soft rock deformation, which dynamically adjusts the stress state of the concrete by real-time monitoring of the deformation of the soft rock.

[0145] The implementation of this technology includes two aspects: the establishment of a deformation monitoring system and the implementation of stress regulation measures. The deformation monitoring system monitors the displacement, strain and stress changes of the soft rock in real time by setting monitoring points on the surface and inside the soft rock. The arrangement of monitoring points is optimized according to the geological conditions of the soft rock and the load distribution of the concrete, ensuring that the deformation state of the soft rock can be fully reflected.

[0146] In terms of stress regulation, corresponding measures are taken according to the change trend of the monitoring data. When the monitoring data shows that the deformation speed of the soft rock is too fast, the deformation is slowed down by adjusting the pouring speed of the concrete or adding temporary support; when the monitoring data shows that stress is concentrated in some areas, stress concentration is relieved by local unloading or stress redistribution.

[0147] The key to dynamic stress regulation is to establish the correlation between soft rock deformation and concrete stress. Through a large amount of field monitoring data and theoretical analysis, a corresponding mathematical model is established, which can predict the stress change trend of the concrete according to the real-time data of the soft rock deformation, so as to take corresponding control measures in advance.

[0148] Layered maintenance technology:

[0149] The quality of concrete maintenance directly affects its final strength and durability. In the special environment of soft rock tunnel backfill area, traditional maintenance methods often fail to achieve the desired results. The invention adopts layered maintenance technology, which adopts corresponding maintenance measures according to the characteristics and environmental conditions of different levels of concrete.

[0150] Layered maintenance technology divides the entire concrete structure into three maintenance areas: surface layer, middle layer and bottom layer according to depth. The surface layer of concrete is directly exposed to the air and is easily affected by changes in environmental temperature and humidity, so it adopts a maintenance method of covering and moisturizing and temperature control; the maintenance of the middle layer of concrete mainly considers the emission of internal hydration heat and the maintenance of humidity, and adopts a method of moderate ventilation and humidity adjustment; the bottom layer of concrete needs to consider the influence of the water absorption and thermal conductivity of soft rock on maintenance, and adopts a method of isolation protection and temperature compensation.

[0151] During the maintenance process, special attention is paid to the maintenance quality of the interface between layers. Due to the adoption of the layering pouring method, the bonding quality of the interface between layers has an important influence on the performance of the overall structure. By setting special maintenance measures at the interface between layers, such as increasing humidity and controlling temperature gradient, the effectiveness of the layer bonding is ensured.

[0152] The soft rock tunnel backfill area mass concrete pouring method of the present application effectively improves the interface bonding strength between soft rock and concrete through progressive interface roughening treatment technology, increases the interface shear strength by more than 30%; the spiral layering progressive pouring technology effectively controls the temperature stress of concrete, reduces the maximum temperature stress by more than 25%; the dynamic stress regulation technology based on soft rock deformation significantly improves the long-term stability of the structure, and controls the soft rock deformation within the allowable range.

[0153] The whole construction method has good adaptability and operability, can be flexibly applied under different soft rock geological conditions, and ensures the quality and safety of mass concrete pouring. Through the implementation of the present application, the construction risk can be effectively reduced, the economic and social benefits of the project can be improved, and reliable technical support is provided for the construction of soft rock tunnels.

[0154] The above only describes exemplary embodiments of the present application, and does not limit the protection scope of the present application, any equivalent structural transformation made under the technical concept of the present application, or direct / indirect application in other related technical fields is included in the protection scope of the present application.

Claims

1. A method for pouring mass concrete in a backfill area of a soft rock tunnel, characterized in that, The method comprises the following steps: stabilizing the soft rock tunnel backfill area to form a reinforced area; roughening the soft rock interface in the reinforced area to form a pouring surface; dividing a plurality of continuous pouring units on the pouring surface according to a spiral path; pouring concrete into the plurality of pouring units in layers and sequentially to complete the mass concrete pouring construction of the soft rock tunnel backfill area.

2. The method of claim 1, wherein the method is characterized by, The step of roughening the soft rock interface in the reinforced area to form a pouring surface comprises: testing the hardness of the soft rock interface in the reinforced area to obtain a hardness distribution; dividing the soft rock interface into a plurality of different processing areas according to the hardness distribution; roughening the soft rock interface in the plurality of different processing areas to form the pouring surface.

3. The method of claim 2, wherein the method further comprises: after the step of pouring the mass concrete, pouring a second mass concrete in the backfill area of the soft rock tunnel. The step of dividing the soft rock interface into a plurality of different processing areas according to the hardness distribution comprises: dividing the area of the soft rock interface meeting a first hardness range value into a first sub-processing area; dividing the area of the soft rock interface meeting a second hardness range value into a second sub-processing area; dividing the area of the soft rock interface meeting a third hardness range value into a third sub-processing area; wherein the first hardness range value is greater than the second hardness range value, and the second hardness range value is greater than the third hardness range value.

4. The method of claim 3, wherein the method further comprises: after the step of pouring the mass concrete, pouring a second mass concrete in the backfill area of the soft rock tunnel. The step of roughening the soft rock interface in the plurality of different processing areas to form the pouring surface comprises: chiseling the surface of the soft rock interface corresponding to the first sub-processing area at a first chiseling depth; washing the surface of the soft rock interface corresponding to the second sub-processing area and chiseling the surface of the soft rock interface corresponding to the second sub-processing area at a second chiseling depth; cleaning and flattening the surface of the soft rock interface corresponding to the third sub-processing area to form the pouring surface; wherein the first chiseling depth is greater than the second chiseling depth.

5. The method of claim 3, wherein the method further comprises: after the step of pouring the mass concrete, pouring a second mass concrete in the backfill area of the soft rock tunnel. The step of dividing a plurality of continuous pouring units on the pouring surface according to a spiral path comprises: setting a spiral line on the pouring surface extending outward from the geometric center of the pouring surface to form the spiral path.

6. The soft rock tunnel backfill area mass concrete pouring method according to claim 5, characterized in that, The pitch of the spiral line located in the first sub-processing area is greater than the pitch of the spiral line located in the second sub-processing area, and the pitch of the spiral line located in the second sub-processing area is greater than the pitch of the spiral line located in the third sub-processing area.

7. The soft rock tunnel backfill zone mass concrete placing method according to any one of claims 1 to 6, characterized in that, The step of pouring concrete into the plurality of pouring units in layers and sequentially to complete the mass concrete pouring construction of the soft rock tunnel backfill area comprises: pouring concrete into the plurality of pouring units according to the spiral path to form a bottom layer of concrete; pouring concrete on the bottom layer of concrete according to the spiral path to form a middle layer of concrete; pouring concrete on the middle layer of concrete according to the spiral path to form a surface layer of concrete, completing the mass concrete pouring construction of the soft rock tunnel backfill area.

8. The soft rock tunnel backfill area mass concrete pouring method according to claim 7, characterized in that, The step of pouring concrete into the plurality of pouring units in layers and sequentially to complete the mass concrete pouring construction of the soft rock tunnel backfill area further comprises: Before pouring concrete on the bottom layer of concrete to form the middle layer of concrete according to the spiral path, the bottom layer of concrete is isolated, protected and temperature compensated to maintain the bottom layer of concrete; Before pouring concrete on the middle layer of concrete to form the surface layer of concrete according to the spiral path, the middle layer of concrete is ventilated and humidity adjusted to maintain the middle layer of concrete; After pouring concrete on the middle layer of concrete to form the surface layer of concrete according to the spiral path, the surface layer of concrete is covered, moisturized and temperature controlled to maintain the surface layer of concrete.

9. The soft rock tunnel backfill area mass concrete pouring method according to claim 7, characterized in that, Before the step of pouring concrete into a plurality of pouring units according to the spiral path to form the bottom layer of concrete, the soft rock tunnel backfill area mass concrete pouring method further comprises: Preheating the surface of the soft rock interface corresponding to the plurality of pouring units.

10. The soft rock tunnel backfill zone mass concrete placement method according to any one of claims 1 to 6, characterized in that, The step of layering and sequentially pouring concrete into a plurality of pouring units to complete the soft rock tunnel backfill area mass concrete pouring construction comprises: Monitoring the displacement, strain and stress change of the soft rock interface corresponding to the plurality of pouring units to obtain monitoring results; Layering and sequentially pouring concrete into a plurality of pouring units, and adjusting the pouring of concrete according to the monitoring results until the soft rock tunnel backfill area mass concrete pouring construction is completed.

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