CN210068175U - A protective structure for preventing tunnel slip casting reinforcement from arousing earth's surface uplift - Google Patents

A protective structure for preventing tunnel slip casting reinforcement from arousing earth's surface uplift Download PDF

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CN210068175U
CN210068175U CN201920887243.XU CN201920887243U CN210068175U CN 210068175 U CN210068175 U CN 210068175U CN 201920887243 U CN201920887243 U CN 201920887243U CN 210068175 U CN210068175 U CN 210068175U
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tunnel
arch
grouting
reverse
ground
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王树仁
张纪云
李春柳
龚健
王新宇
许来斌
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Henan University of Technology
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Henan University of Technology
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Abstract

The utility model relates to a protective structure for preventing tunnel slip casting reinforcement from arousing earth's surface uplift, technical scheme is, including the tunnel body that is located stratum surface below, be provided with the reverse arch that forms by earth's surface slip casting in the stratum directly over the tunnel body, reverse arch is downward bellied arch, is provided with supporting construction on the top group of outline in the tunnel body, around the top group of outline in the tunnel body, is provided with the forward arch that forms by drilling slip casting in supporting construction's the outside, forward arch is upward bellied arch, the utility model discloses a level, many times slip casting and jointly multiple passive supporting mode form the stress supporting body jointly, have successively formed reverse arch and forward arch structure, change the loose rock stratum such as loose rock stratum, sand layer around the tunnel, thereby can realize to the stress distribution state on the loose ground layer such as surrounding environment, Under the condition that the property of rock soil is not mastered accurately, high-pressure grouting is formed through protection of the reverse camber.

Description

A protective structure for preventing tunnel slip casting reinforcement from arousing earth's surface uplift
Technical Field
The utility model belongs to the technical field of geotechnical engineering and civil engineering municipal administration, especially one kind is used for preventing that tunnel slip casting from consolidating the protective structure who arouses the earth's surface uplift. The method is suitable for permanent tunnel (roadway) engineering with a series of problems such as surface uplift, road cracking, building inclination and the like easily caused by advanced grouting reinforcement when a shallow-buried tunnel (roadway) passes through loose rock strata and sand layers.
Background
With the development of economic globalization and the acceleration of urbanization process, subway engineering is becoming the main direction of urban public transport development. The subway enhances the travel rapidity, saves the time of people, and plays a good promoting role in developing the environment-friendly construction of cities. China is in the period of accelerated development of industrialization and urbanization, millions of people flow into a large city, and great pressure is brought to city management and city traffic. Compared with other projects, the subway project is a large civil engineering with large investment, long construction period and complex technology. Subway engineering has characteristics such as disguise, geological environment's uncertainty, construction technique complexity, and this will cause the engineering to have a great amount of risks, kind complicacy in construction period, even cause great economic loss after the accident appears.
The subway is in the urban area with loud cities, dense population and dense building and construction, and the tunnel (roadway) excavated for building the subway is positioned at the shallow part of the whole earth crust, so that the difficulty of excavation and support is undoubtedly increased when the tunnel (roadway) needs to pass through loose rock strata and sand soil layers. On the national scale, subways are generally built at about 20 meters underground, and according to statistics, 4 subway cities of Beijing, Tianjin, Guangzhou and Shanghai are built, built tunnels (roadways) are about 20 meters underground, and the depth of a Beijing line V reaches 24 meters. The subway construction depth is different according to different soil, geology and line distribution, and some countries in the world such as Russia, London and the like have about 50 meters underground.
Aiming at the condition that a tunnel (roadway) is positioned in a loose rock stratum and a sand stratum and can pass through the loose rock stratum, the ground existing road or other building structures during construction, only a few end parts of the construction of the common tunnel (roadway) adopt an open excavation method at present, and ninety percent of the route length adopts methods such as a drilling and blasting method, a shield method, a digging machine method, a new Austrian method and the like in an underground excavation method. The original stable rock-soil layer excavation through the tunnel (roadway) must change the original stress state to cause the stress redistribution. The weight of overlying strata and building structures can cause the deformation of tunnels (roadways), so the excavated tunnels (roadways) must be supported, and loose strata and sandy soil layers between the tunnels (roadways) and the ground surface need to be reinforced, and the loose strata and the sandy soil layers are called burial depth. At present, the method of grouting is basically adopted for reinforcing the part of rock and soil mass, because the buried depth of a tunnel (lane) is shallow, the tunnel (lane) is a thin shell relative to the thickness of the whole stratum, the tunnel (lane) is close to the earth surface, in order to achieve the effect of grouting reinforcement, large grouting pressure is generally needed, but the overlarge grouting pressure can cause the rock and soil mass to arch up until the earth surface bulges, the original state of the earth surface is damaged, the earth surface road is cracked, and the building and construction objects are unevenly settled. At this time, if the grouting pressure is reduced, although the purpose of controlling the deformation of the ground surface bulge can be achieved, the effect of reinforcing the rock-soil mass cannot be achieved due to the fact that the slurry diffusion radius is reduced directly caused by too low pressure. The diffusion radius of the grout is obtained according to experience and is about 25cm generally, so that the distance between grouting drill holes is designed to be about 50cm generally in practical construction, so that the grout diffusion radii of two grouting holes are crossed and overlapped under effective grouting pressure, and the rock and soil mass between the grouting holes is fully reinforced. If the grouting pressure is reduced, not only the diffusion radius of the slurry is reduced, but also the conventional grouting hole spacing cannot ensure that the surrounding rock-soil mass is fully reinforced, so that the grouting body is discontinuous, and the stress state of the slurry-rock-soil mixture is influenced, therefore, the improvement and innovation of the grouting device are imperative.
SUMMERY OF THE UTILITY MODEL
To the above situation, for overcoming prior art's defect, the utility model aims at providing a protective structure and the leading slip casting method of tunnel for preventing tunnel slip casting reinforcement from arousing the earth's surface uplift, can effectively solve and prevent that slip casting reinforcement from arousing the problem of earth's surface uplift.
The utility model provides a technical scheme be: the protective structure comprises a tunnel body located below the surface of a ground layer, wherein a reverse arch formed by surface grouting is arranged in the ground layer right above the tunnel body, the reverse arch is in a downward-convex arch shape, a supporting structure is arranged on a top wall of the inner outline of the tunnel body, the top wall surrounds the inner outline of the tunnel body, a forward arch formed by drilling grouting is arranged on the outer side of the supporting structure, the forward arch is in an upward-convex arch shape, and the forward arch, the reverse arch and the supporting structure jointly form a united body supporting structure for preventing advanced grouting from causing surface uplift.
The supporting structure is an anchor rod hanging net spray anchor support or a steel arch frame support or a combined support formed by the anchor rod hanging net spray anchor support or the steel arch frame support or the anchor rod hanging net spray anchor support and the steel arch frame support.
The thickness of the reverse camber arch is 3-4m, and the thickness of the forward camber arch is more than 2 m.
The projection length of the reverse camber along the width direction on the horizontal ground is L, the projection length is used as the span of the reverse camber, the depth from the lowest point of the reverse camber to the horizontal ground is H, the rise is used as the rise, the rise-span ratio of the reverse camber is △ K, △ K is H/L, and △ K is 1/5-1/6.
And the vertical central line of the tunnel body, the vertical central line of the forward camber arch and the vertical central line of the reverse camber arch are collinear.
The top wall of the inner contour of the tunnel body is provided with an advanced grouting pipe which is obliquely arranged towards the tunnel trend, and an outlet of the advanced grouting pipe is positioned between the coverage range of the forward camber arch and the coverage range of the reverse camber arch.
A method for preventing the tunnel with the raised ground surface from being grouted in advance based on the protective structure comprises the following steps:
A. surface drilling grouting
Before a tunnel is constructed to a section to be protected, earth surface drilling is carried out on the surface of a stratum with a loose rock-soil layer right above the trend of the tunnel body along the trend of the tunnel body, the drilling holes are arranged in a quincunx shape, the overlooking central connecting line of the drilling holes in the same row is vertical to the trend of the tunnel, the drilling depth in the center is the largest in the drilling holes in the same row, the drilling depth is sequentially decreased from the center to two sides, and the lower ends of the drilling holes in the same row are all positioned in the designed reverse camber range of the section;
placing a repeatable grouting pipe into the drilled hole, and performing grouting operation through the repeatable grouting pipe to enable the grout and the loose rock-soil layer to form an integral supporting structure to jointly form a reverse camber arch;
B. tunnel support
When the tunnel is constructed to a section to be protected, firstly digging out a rough section of the tunnel body, carrying out primary concrete spraying and mounting a supporting structure, and finally spraying concrete again;
C. tunnel drilling grouting
After the concrete is sprayed again for 1 day, drilling holes and grouting around the top wall of the inner outline of the tunnel body to form a positive camber arch;
D. advanced grouting
Performing advanced grouting between the reverse camber arch and the forward camber arch;
E. floor pouring
And (5) pouring concrete on the bottom plate of the tunnel to form the tunnel section size meeting the design requirement.
The designed reverse camber arch is positioned in a loose rock-soil layer right above the tunnel trend, the designed reverse camber arch is in a downward convex arch shape, the projection length of the reverse camber arch on the horizontal ground along the width direction is L and is used as the span of the reverse camber arch, the depth from the lowest point of the reverse camber arch to the horizontal ground is H and is used as the rise, the rise-span ratio of the reverse camber arch is △ K, △ K is H/L, and △ K is 1/5-1/6;
the lower end of the repeatable grouting pipe is equal to the lower end face of the designed reverse camber arch in distance.
The grouting operation in the step A is as follows:
and (3) performing initial grouting at the lower end of the repeatable grouting pipe, which is not more than 10cm away from the bottom of the drilled hole, injecting solidified grout into the grouting hole through the repeatable grouting pipe, wherein the initial grouting adopts filling grouting, the grouting pressure is controlled to be less than 0.5Mpa, and the used grouting liquid is 325# cement, an additive and water in a ratio of 1:0.08: 2.
And after 2-3h of the initial grouting is finished, the grout reaches an initial setting state, the grout is primarily bonded with the loose rock stratum and the sand soil layer in the loose rock-soil layer into a whole, after certain bearing strength is achieved, secondary grouting is carried out, the grouting pressure of the secondary grouting is greater than that of the primary grouting and is controlled to be less than 3Mpa, retreating sectional grouting is adopted, the used grouting liquid is 325# cement, additives and water, the proportion of the used grouting liquid is 1:0.08:2, the retreating sectional grouting thickness is 3-4m until a complete reverse camber is formed, so that the strength of the loose rock-soil layer is improved, an internal grouting reinforcement body is formed through the initial grouting and the secondary grouting, and the internal reinforcement body and the surrounding loose rock-soil layer form a whole supporting structure to jointly form the reverse camber for stress bearing.
The beneficial effects of the utility model reside in that, utilize the space stabilization theory of curved arch and conventional anchor shotcrete to strut, passive support forms such as steel bow member adds shotcrete support or combined support combine organically, through the hierarchy, many times slip casting and the joint multiple passive support mode form stress-carrying body jointly, reverse curved arch and forward curved arch structure have successively been formed, change the stress distribution state of loose ground layers such as loose rock stratum, sand layer around tunnel (lane), shift out the peak value of stress concentration three areas of stress area of tunnel (lane), make full use of curved arch shape has the characteristics that bearing capacity is big, cut off the influence of the dynamic and static load on tunnel (lane) on the ground surface, also cut off tunnel (lane) too big influence of slip casting pressure building in advance to earth surface road, construct the influence of building, guaranteed mutual stability between them respectively, can realize high-pressure ground, both controlled the ground surface, the steel bow member is with shotcrete to be strutted, the anchor shotcrete is strutted, the structure is good at the foundation, The deformation of the building structure prevents the rise of the earth surface, and fully realizes the grouting reinforcement effect of the loose rock-soil layer. The loose rock-soil body is repaired in strength and rigidity through high-pressure grouting, integrity and bearing capacity of surrounding rock are improved, the loose rock-soil body on the upper portion of a tunnel (roadway) is in a good stable state for a long time, and therefore high-pressure grouting is formed through protection of the reverse camber arch under the condition that the surrounding environment and rock-soil properties are not mastered accurately. The utility model discloses a method range of application is extensive, and is all suitable for newly digging and reprocess tunnel (lane), is particularly useful for the engineering that shallow tunnel (lane) way passes through loose rock stratum, sand layer, the utility model discloses easily form one set of perfect construction technical measure, it is simple to have a method, the implementation of being convenient for, mechanized convenient operation, strut effectual characteristics, the engineering popularization and application value that has apparent economic benefits along with the continuous development of shallow underground works.
Drawings
Fig. 1 is a schematic view of the overall layout section of the present invention.
FIG. 2 is a schematic sectional view of the reverse camber arch arrangement of the present invention;
FIG. 3 is a schematic cross-sectional view of an arrangement of a pre-grouting reinforcement zone;
FIG. 4 is a general plan view of a method of reverse continuous camber to prevent grouting reinforcement from causing surface elevations.
Wherein: 1. a surface of the formation; 2. drilling the earth surface; 3. the grouting pipe can be repeated; 4. a loose rock-soil layer; 5. a reverse camber; 6. an advanced grouting pipe; 7. shallow grouting holes; 8. a tunnel body; 9. a vertical centerline of the tunnel body; 10. a base plate; 11. positive camber; 12. an advanced grouting reinforcement area; 13. an anchor rod; 14. a transverse centerline of the tunnel body; 15. the hair section of the tunnel body; 16. a steel arch frame.
Detailed Description
The following describes the embodiments of the present invention in further detail with reference to the accompanying drawings.
As shown in fig. 1-4, the utility model relates to a protective structure for preventing tunnel slip casting reinforcement arouses earth's surface uplift, including the tunnel body 8 that is located stratum surface 1 below, be provided with the reverse bent arch 5 that forms by earth's surface slip casting in the stratum directly over tunnel body 8, reverse bent arch 5 is downwardly convex arch, is provided with supporting construction on the top group of profile in tunnel body 8, centers on the top group of profile in tunnel body, is provided with the forward bent arch 11 that forms by drilling slip casting in the outside of supporting construction, forward bent arch 11 is the bellied arch that makes progress, and forward bent arch 11, reverse bent arch 5 and supporting construction form jointly and prevent that advance slip casting from arousing the complex body supporting construction that the earth's surface uplift.
In order to ensure the using effect, the supporting structure is a combined support formed by an anchor rod hanging net spray anchor support 13 or a steel arch support 16 or the combination of the two, which are arranged on the inner wall of the tunnel body 8.
The thickness of the reverse camber arch 5 is 3-4m, and the thickness of the forward camber arch 11 is larger than 2 m.
The projection length of the reverse camber arch 5 on the horizontal ground along the width direction is L, the depth from the lowest point of the reverse camber arch 5 to the horizontal ground is H as the span of the reverse camber arch, the vector-span ratio of the reverse camber arch is △ K as the vector height, △ K is H/L, and △ K is 1/5-1/6.
And if the surface of the ground is not horizontal, taking the lowest point of the reference of the horizontal ground.
The distance between the forward curved arch 11 and the reverse curved arch 5 is larger than 2m, the distance between the vault (the lowest point) of the reverse curved arch and the vault (the highest point) of the forward curved arch is selected according to actual conditions due to different buried depths of the underground space tunnel, and high-pressure grouting is performed on the interlayer of the forward curved arch and the reverse curved arch under the protection of the forward curved arch and the reverse curved arch to achieve the effect of reinforcing the surrounding rock mass and the effect of cooperative stress of the surrounding rock mass and grouting body.
And the vertical central line 9 of the tunnel body 8, the vertical central line of the forward camber 11 and the vertical central line of the reverse camber 5 are collinear.
An advanced grouting pipe 6 which is obliquely arranged towards the tunnel trend is arranged on the top side of the inner outline of the tunnel body 8, and the outlet of the advanced grouting pipe 6 is positioned between the coverage range of the forward camber arch 11 and the coverage range of the reverse camber arch 5.
The advanced grouting pipes 6 are arranged according to the existing specifications, and are generally arranged by inclining 30-60 degrees outwards according to the trend of the corresponding tunnel, the spacing is generally controlled to be about 0.5m, and the drilling angle and spacing can be properly adjusted when meeting special geological conditions, and the technology is the prior art. The method specifically comprises the following steps: a grouting hole with a certain depth is punched at the top wall in a tunnel (roadway) to install a grouting pipe for medium-length hole grouting operation to form an internal grouting reinforcement body, the grouting pressure of medium-length hole advanced grouting can be properly improved under the protection of a reverse continuous camber arch 5 and a forward camber arch 11, the grouting pressure is generally controlled to be below 8MPa, and the used grouting liquid is composed of 425# cement, an additive and water in a ratio of 1:0.08: 2.
The top wall of the inner contour of the tunnel body 8 is composed of an upper circular arc-shaped part and lower vertical edge parts connected to the two ends of the circular arc-shaped part.
The method for preventing the tunnel with the raised ground surface from being grouted in advance of the protective structure comprises the following steps:
A. surface drilling grouting
Before a tunnel is constructed to a section to be protected, transferring temporary facilities needing to be transferred due to construction on the surface of a ground layer, arranging a grouting station at a proper position to prepare for subsequent reverse camber grouting, drilling 2 on the surface of the ground layer with a loose rock-soil layer 4 right above the direction of the tunnel body along the direction of the tunnel body, wherein the diameter of a drill hole is preferably slightly larger than the diameter of a grouting pipe, the drill hole is arranged in a quincunx shape, a overlook central connecting line of the drill holes in the same row is vertical to the direction of the tunnel, the depth of the drill hole in the center is the largest in the drill holes in the same row, the depth of the drill holes in the center is gradually reduced from the center to two sides, and the lower end of the drill hole in the same row is positioned in;
the distance between the earth surface drill holes 2 is 0.4-0.6 m;
the repeatable grouting pipe 3 is placed in the drilled hole, the repeatable grouting pipe is made of a plastic pipe (PVC pipe) with good hardness and elasticity, the bottom end of the repeatable grouting pipe is sealed, a circle of small grouting holes are drilled in the pipe wall at intervals (such as 15-20cm), a certain number of small grouting holes (such as 3-4) are arranged in each circle at equal intervals, and the small grouting holes in the repeatable grouting pipes are identical in relative height, so that the grout can be uniformly and equivalently spread around the grouting holes.
Grouting operation is carried out through the repeatable grouting pipe 3, so that the grout and the loose rock-soil layer 4 form an integral supporting structure to jointly form a reverse camber arch 5;
B. tunnel support
When the tunnel is constructed to a section to be protected, firstly digging out a rough section 15 of the tunnel body, carrying out primary concrete spraying and mounting a supporting structure, and finally spraying concrete again;
the specific method comprises the following steps: when the tunnel is constructed to a section to be protected, firstly digging out a rough section 15 of a tunnel body, immediately performing primary concrete spraying, wherein the thickness of the primary concrete is generally 20-30mm, then performing anchor rod net hanging and anchor spraying support 13, steel arch support 16 or the combined support of the anchor rod net hanging and anchor spraying support and the steel arch support to the excavated tunnel (tunnel) according to the characteristics and the strength grade of the surrounding rock-soil layer to form a support structure, finally performing secondary concrete spraying, wherein the thickness is generally 80-100mm, after the secondary spraying is completed, manually processing the underexcavated part, filling the overetched part, properly processing the ends of the leaked anchor rods and anchor cables, and finally performing leveling processing to the whole tunnel (tunnel) to ensure that the shape and the size of the section of the whole tunnel (tunnel) accord with the design.
C. Tunnel drilling grouting
After the concrete is sprayed again for 1 day, drilling holes and grouting around the top wall of the inner outline of the tunnel body to form a forward camber arch 11;
the specific method comprises the following steps: after the concrete is re-sprayed for 1 day, a shallow grouting hole 7 with the depth of less than 2m is drilled at the top side of the tunnel (lane), then a grouting pipe is installed for grouting, the grouting pressure is generally controlled to be less than 5Mpa, the used grouting liquid is composed of 425# cement, an additive and water, the proportion is 1:0.08:2, a forward curved arch 11 is formed around the shape of the top side of the tunnel (lane), and the forward curved arch 11 and a supporting structure form a united body supporting structure together.
D. Advanced grouting
Performing advanced grouting reinforcement in an advanced grouting reinforcement area 12 between the reverse camber arch 5 and the forward camber arch 11;
the specific method comprises the following steps: the method is characterized in that a grouting hole with a certain depth is drilled at the top wall in a tunnel (roadway), an advanced grouting pipe 6 is installed to conduct medium-length hole grouting operation, an internal grouting reinforcement body is formed, the outlet of the advanced grouting pipe 6 is located between the coverage range of a forward curved arch 11 and a reverse curved arch 5, the grouting pressure of the medium-length hole advanced grouting 6 can be properly improved under the protection of the reverse curved arch 5 and the forward curved arch 11, the grouting pressure is generally controlled to be below 8Mpa, the used grouting liquid is composed of 425# cement, an additive and water, the proportion of the used grouting liquid to the medium-length hole advanced grouting pipe is 1:0.08:2, the distance between the advanced grouting pipes is generally controlled to be about 0.5m, and the drilling angle and distance of the grouting hole can be properly adjusted under the special geological conditions.
E. Floor pouring
And (5) pouring concrete on the bottom plate 10 of the tunnel to form the section size of the tunnel meeting the design requirement.
The designed reverse camber arch is positioned in the loose rock-soil layer 4 right above the tunnel trend, the designed reverse camber arch is in a downward convex arch shape, the projection length of the reverse camber arch 5 on the horizontal ground along the width direction is L and is used as the span of the reverse camber arch, the depth from the lowest point of the reverse camber arch 5 to the horizontal ground is H and is used as the rise, the rise-span ratio of the reverse camber arch is △ K, △ K is H/L, and △ K is 1/5-1/6;
the lower end of the repeatable grouting pipe 3 is equal to the lower end face of the designed reverse camber arch in distance.
The surface borehole depth can be determined by the following two methods:
a. the ground reverse continuous arch grouting belongs to surface layer grouting, the drilling depth is generally 6-7m, the specific depth is determined according to the thickness of a loose rock-soil layer consisting of a loose rock stratum and a sand layer or the distance between a tunnel (roadway) and the ground surface, and then the L can be calculated according to the selected delta K;
b. in practice, the width of the building to be protected is easy to measure, so that L is easy to determine, and after a proper delta K is selected, the depth H of a grouting hole can be calculated, but the requirement that the distance between the forward curved arch 11 and the reverse curved arch 5 is larger than 2m must be met.
The grouting operation in the step A is as follows:
the lower end of the repeatable grouting pipe is not more than 10cm away from the bottom of a drill hole, initial grouting is firstly carried out, solidified grout is injected into the grouting hole through the repeatable grouting pipe, filling grouting is adopted for the initial grouting, the grouting pressure is controlled to be less than 0.5Mpa (the situation that the shape of the reverse camber arch 5 is damaged due to overlarge grouting pressure and the bearing capacity of the whole loose rock-soil layer is influenced) and the used grouting liquid is 325# cement, an additive and water, and the proportion of the used grouting liquid to the integral loose rock-soil layer is 1:0.08: 2.
After the initial grouting is finished for 2-3h, the grout reaches the initial setting state, the grout is primarily bonded with the loose rock stratum and the sand soil layer in the loose rock-soil layer (4) into a whole, after a certain bearing strength is achieved, secondary grouting is carried out, the grouting pressure of the secondary grouting is greater than that of the primary grouting, and is controlled to be less than 3Mpa, retreating sectional grouting is adopted, the grouting liquid is composed of 325# cement, additive and water, the proportion is 1:0.08:2, the receding sectional grouting thickness is 3-4m until a complete reverse camber arch 5 is formed, so as to achieve the effect of improving the strength of the loose rock-soil layer, after grouting, the grouting pipe is flushed by water to remove residual slurry in the pipe, an internal grouting reinforcement body is formed through primary grouting and secondary grouting, and the internal grouting reinforcement body and a surrounding loose rock-soil layer form an integral supporting structure to jointly form a reverse camber arch 5 for stress bearing.
The retreating sectional type grouting is the prior art, and simply means that after the first grouting is finished, the grouting pipe is lifted for a certain distance, for example, 20-30cm, the second grouting is carried out, after the second grouting is finished, the grouting pipe is lifted for 20-30cm again for carrying out the third grouting, and the steps are repeated until the grouting thickness reaches 3-4 m.
From the above situation, the utility model utilizes the space stability theory of the curved arch to organically combine with the passive support modes such as the conventional anchor-jet support, the steel arch frame with the jet anchor support or the combined support, and forms the stress bearing body by the layering, the multiple grouting and the combined multiple passive support modes, thereby forming the reverse curved arch and the forward curved arch structure, changing the stress distribution state of the loose rock strata, the sand stratum and other loose rock strata around the tunnel (lane), shifting the peak value of the stress concentration out of the three-belt stress area of the tunnel (lane), fully utilizing the curved arch shape to have the characteristic of large bearing capacity, isolating the influence of the dynamic and static loads on the surface of the ground stratum on the tunnel (lane), and simultaneously isolating the influence of the excessive advanced grouting pressure of the tunnel (lane) on the surface road and the building structure, respectively ensuring the mutual stability of the ground surface road and the building structure, and realizing the high-pressure grouting, the deformation of the ground surface and the building structure on the surface of the ground is controlled, the uplift of the ground surface is prevented, and the grouting reinforcement effect of the loose rock-soil layer is fully realized. The loose rock-soil body is repaired in strength and rigidity through high-pressure grouting, integrity and bearing capacity of surrounding rock are improved, the loose rock-soil body on the upper portion of a tunnel (roadway) is in a good stable state for a long time, and therefore high-pressure grouting is formed through protection of the reverse camber arch under the condition that the surrounding environment and rock-soil properties are not mastered accurately. The utility model discloses a method range of application is extensive, and is all suitable for newly digging and reprocess tunnel (lane), is particularly useful for the engineering that shallow tunnel (lane) way passes through loose rock stratum, sand layer, the utility model discloses easily form one set of perfect construction technical measure, it is simple to have a method, the implementation of being convenient for, mechanized convenient operation, strut effectual characteristics, the engineering popularization and application value that has apparent economic benefits along with the continuous development of shallow underground works.
The applicant shall additionally point out that the above description is only a description of the general implementation steps of the present invention, and not a limitation of the present invention in any form, so any modification and variation of the above construction steps depending on the theoretical basis and technical entity of the present invention all belong to the protection scope of the present invention.

Claims (6)

1. The protection structure for preventing the earth surface uplift caused by the grouting reinforcement of the tunnel comprises a tunnel body (8) located below a ground surface (1), and is characterized in that a reverse camber arch (5) formed by the grouting of the earth surface is arranged in the ground layer right above the tunnel body (8), the reverse camber arch (5) is of an arch shape protruding downwards, a supporting structure is arranged on a top side of the inner outline of the tunnel body (8), the supporting structure surrounds the top side of the inner outline of the tunnel body, a forward camber arch (11) formed by the drilling grouting is arranged on the outer side of the supporting structure, the forward camber arch (11) is of an arch shape protruding upwards, and the forward camber arch (11), the reverse camber arch (5) and the supporting structure jointly form a supporting combination structure for preventing the advance grouting from causing the uplift of the earth surface.
2. The protective structure for preventing the ground surface uplift caused by the grouting reinforcement of the tunnel according to claim 1, wherein the supporting structure is a bolting-shotcrete support (13) or a steel arch support (16) or a combined support of the bolting-shotcrete support and the steel arch support which are arranged on the inner wall of the tunnel body (8).
3. The protective structure for preventing the ground surface from uplifting due to grouting reinforcement for tunnels according to claim 1, wherein the thickness of the reverse camber arch (5) is 3-4m, and the thickness of the forward camber arch (11) is more than 2 m.
4. The shelter structure for preventing ground uplift caused by grouting reinforcement for tunnels according to claim 1, wherein the projection length of the reverse camber arch (5) in the width direction on the horizontal ground is L, the span of the reverse camber arch is H, the depth from the lowest point of the reverse camber arch (5) to the horizontal ground is H, the rise of the reverse camber arch is △ K, and the rise-to-span ratio of △ K H/L is △ K is 1/5-1/6.
5. The protective structure for preventing the uplift of the ground surface caused by the grouting reinforcement of the tunnel according to claim 1, wherein the vertical center line (9) of the tunnel body (8), the vertical center line of the forward camber (11), and the vertical center line of the reverse camber (5) are collinear.
6. The protective structure for preventing the ground surface uplift caused by the grouting reinforcement of the tunnel according to claim 1, wherein a leading grouting pipe (6) which is obliquely arranged towards the tunnel trend is arranged on the top wall of the inner contour of the tunnel body (8), and the outlet of the leading grouting pipe (6) is positioned between the coverage range of the forward camber arch (11) and the coverage range of the reverse camber arch (5).
CN201920887243.XU 2019-06-13 2019-06-13 A protective structure for preventing tunnel slip casting reinforcement from arousing earth's surface uplift Active CN210068175U (en)

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Publication number Priority date Publication date Assignee Title
WO2020248596A1 (en) * 2019-06-13 2020-12-17 河南理工大学 Protection structure for preventing ground heave caused by tunnel grouting reinforcement and grouting method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2020248596A1 (en) * 2019-06-13 2020-12-17 河南理工大学 Protection structure for preventing ground heave caused by tunnel grouting reinforcement and grouting method

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