CN116377778A - Construction method and settlement treatment method of rock slope overhanging type road structure - Google Patents

Abstract

The invention discloses a construction method and a settlement treatment method of a rock slope overhanging type road structure, which relate to the field of road engineering and aim to improve the stress of the road structure so that the road structure is more economical and reasonable, and the adopted technical scheme is as follows: the construction method of the rock slope overhanging type road structure comprises the following steps: excavating the pile body to form a base for constructing the foundation of the external retaining wall; constructing an outer retaining wall foundation on a substrate; constructing an outer retaining wall on the upper part of the outer retaining wall foundation; backfilling the inner side of the outer baffle wall to form a backfill roadbed; constructing anchoring parts in the bedrock roadbed at the inner side of the backfill roadbed; and constructing a road panel on the upper parts of the backfill roadbed and the bedrock roadbed, wherein the upper ends of the anchoring pieces are connected with the road panel. The settlement treatment method of the rock slope overhanging type road structure comprises the steps of reserving or forming grouting holes on a road panel, and grouting through the grouting holes when settlement occurs on a backfill roadbed. The invention is used for designing, constructing and maintaining the road on the rock slope.

Description

Construction method and settlement treatment method of rock slope overhanging type road structure

Technical Field

The invention relates to the field of road engineering, in particular to a road structure which is built on a rocky slope, wherein part of roadbeds of an open road section are bedrock on the mountain side, part of roadbeds are covering layers and slag filling, a building method of the road structure, and a treatment method for subsidence of the road structure.

Background

Hydropower stations are built in mountain gorge areas, dangerous terrains and steep slopes and valleys, and the places are rare. The road is repaired first to connect with the outside traffic. Roads are built in canyons, and open road sections mostly pass through natural slopes in a half-cut and half-fill mode. The semi-amplitude roadbed at the mountain side of some road sections is a bedrock, and the semi-amplitude roadbed at the ditch side or the river side is a deep covering layer and slag filling. The covering layer and the slag filling belong to loose piles, the piles can basically reach a self-stabilizing state through natural sedimentation for one year, and Bian Poji can reach a stable state through natural sedimentation for 3-5 years, but the engineering construction period and the use requirements are not allowed to wait for 3-5 years, and then the road is built.

The road cannot pass directly over unstable or suspended slag. In order to ensure the road traffic safety and adapt to the settlement deformation of the slag filling, certain engineering measures are needed to be taken, and then the road is built. The method for constructing the outer retaining wall on the upper part of the half-suspended deep coverage layer or the slag filling comprises the following three steps: firstly, excavating to a bedrock surface, constructing anchor rods on the bedrock surface, climbing and pouring concrete to form a retaining wall expansion foundation, then constructing a balance weight type retaining wall on the expansion foundation, and backfilling the inner side of the wall to form a roadbed and a pavement; constructing pile foundation joists on the tops of the filling slag, constructing a balance-weight retaining wall on the pile foundation joists, and backfilling the inner sides of the balance-weight retaining wall to form a roadbed; and thirdly, when the span is not large, adopting a half-span arch bridge to span, and forming the pavement. For the first method, the depth of the retaining wall is very deep, and the potential side slope collapse, high falling, road breaking and other safety risks and adverse conditions are caused in the excavation process; the large-scale construction mechanical equipment is adopted to realize the excavation by matching with manpower, the construction space is limited, the edge working is high in safety risk, and the operation is inconvenient; taking a strong unloading rock slope surface as a foundation, wherein the potential retaining wall is unstable in the foundation to cause the risk of integral collapse and overturning of the retaining wall; the method has the advantages of high construction difficulty, high safety risk, long construction period, large concrete consumption and uneconomical construction. The second method has the advantages of high construction safety risk, long construction period and high construction cost of the hole digging pile. The third method is not applicable when the span is large, is not applicable when the bridge bases at the two ends do not meet the requirements, and has the defects of long period, high manufacturing cost and uneconomical.

Disclosure of Invention

The invention firstly provides a rock slope overhanging type road structure, and aims to improve the stress of the road structure and make the road structure more economical and reasonable.

The technical scheme adopted by the invention is as follows: the utility model provides a road structure is encorbelmented on rock matter slope, includes outer barricade and road panel, and the bottom of outer barricade is outer barricade foundation, and the inboard of outer barricade is backfill road bed, and the one side of backfill road bed back to outer barricade is the bedrock road bed, and the upper portion of backfill road bed and bedrock road bed is road panel, sets up the anchor assembly in the bedrock road bed, and the upper end and the road panel of anchor assembly are connected.

Since the outer retaining wall and the backfill roadbed generally settle, in order to facilitate treatment of settlement through grouting, further: and grouting holes are formed in the part of the road panel corresponding to the backfill roadbed. In order to prevent rainwater from flowing into the backfill roadbed from the grouting holes, further: a temporary blocking body is arranged in the grouting hole. For example: the temporary blocking body is clay.

In order to reduce the height of the outer retaining wall to reduce the amount of excavation and masonry, further: the outer retaining wall foundation comprises a concretion body obtained by arranging grouting anchor rods on a pile body and grouting, a cushion layer laid on the top of the concretion body, and an expansion foundation laid on the top of the cushion layer, wherein the upper ends of the grouting anchor rods are positioned in the expansion foundation, and the outer retaining wall is positioned on the upper part of the expansion foundation. For example, the length of the grouting anchor rod is 3-4 m, the grouting anchor rod is longitudinally arranged in 2-3 rows along the road, and the grouting anchor rod is a self-advancing hollow grouting anchor rod, and the model is A25 or A32.

In order to effectively drain the accumulated water in the backfill roadbed, further: the outer retaining wall is provided with a water discharge hole, and the backfill roadbed is provided with a reverse filtering layer at the inner side of the outer retaining wall. The water discharge holes are uniformly distributed on the outer retaining wall and incline to the outer side of the outer retaining wall.

In order to improve the self-stability of the outer retaining wall, further: the outer retaining wall is a balance weight type retaining wall.

Specific: the road panel is a reinforced concrete structure, the reinforcing bars of the road panel comprise transverse reinforcing bars, longitudinal reinforcing bars and stirrups, the transverse reinforcing bars and the longitudinal reinforcing bars are arranged in a double-layer manner, and the upper ends of the anchoring pieces are connected with the reinforcing bars of the road panel. The anchoring piece is an anchor rod or an anchor rope, for example, the anchoring piece is a cement mortar anchor rod with the model number of C22 or C25, and the length of the anchor rod is 3-4 m. The anchors are multiple and uniformly arranged, for example, the anchors are arranged in at least two rows along the longitudinal direction of the road. The anchors are preferably arranged vertically according to the stress of the anchors.

To accommodate uneven settlement of the retaining wall foundation, further: the outer retaining wall is provided with sedimentation gaps at intervals, and the transverse seams between two adjacent road panels are the sedimentation gaps and correspond to the sedimentation gaps of the outer retaining wall. For example, the outer retaining walls are provided with settlement joints at intervals of 6-8 m, and the length of the single road panel is 6-8 m.

Based on the stress and allowable deformation of the road panel, further: the road panel is not provided with longitudinal slits arranged along the road direction, at least one transverse slit is arranged at the part of the road panel positioned on the backfill roadbed, and the transverse slit is not arranged at the part of the road panel positioned on the bedrock roadbed. Specific: the transverse joints between the transverse joints and the road panels are false joints without a force transmission rod.

The rock slope overhanging road structure has the beneficial effects that: according to the use function of the road, on the basis of fully knowing the mechanical properties of the backfill roadbed and the bedrock roadbed, the bearing capacity of the bedrock roadbed is not taken as an index for controlling the bearing capacity of the outer retaining wall foundation, but the bearing capacity of the bedrock roadbed is fully utilized, and the overhanging type road structure similar to a piano key is provided, so that the road panel is allowed to have certain elastic deformation but does not form destructive deformation, the height and masonry amount of the outer retaining wall can be reduced, the convenience and operability of construction are improved, the construction safety risk is reduced, the construction progress is accelerated, the investment is saved, and the requirement of the practical function of the road is met. The part of the road panel corresponding to the backfill roadbed is reserved with grouting holes, when settlement occurs on one side of the backfill roadbed, grouting is performed through the grouting holes, and the backfill roadbed is reinforced in a grouting backfill mode, so that the road is kept smooth.

The invention also provides a construction method of the rock slope overhanging type road structure, which is used for constructing the proposed rock slope overhanging type road structure, and aims to improve the stress of the road structure, so that the road structure is more economic and reasonable, and the adopted technical scheme is as follows: the construction method of the rock slope overhanging type road structure comprises the following steps:

s1, excavating the pile body to form a foundation of the construction outer retaining wall foundation.

S2, constructing an external retaining wall foundation on the substrate. The outer retaining wall foundation is used for bearing an outer retaining wall, and a method for obtaining the outer retaining wall foundation through grouting is provided below, wherein the method comprises S2.1-S2.3.

S2.1, arranging a grouting anchor rod on a substrate, grouting, and reserving an exposed section of the grouting anchor rod.

S2.2, constructing a cushion layer on the substrate and leveling. The thickness of the cushion layer is 10-20 cm, fine stone concrete with large slump and good workability, such as C20 fine stone concrete, can be adopted, and the cushion layer has the functions of leveling and further caulking grouting.

S2.3, constructing an enlarged foundation on the upper part of the cushion layer. The width of the enlarged foundation is determined according to the bottom width of the outer retaining wall, and the width of the enlarged foundation is generally 2-4 m, wherein the width of the enlarged foundation is generally 50-100 cm on the inner side and the outer side of the outer retaining wall respectively. In order to adapt to uneven settlement, the expanded foundation is provided with parting joints at the positions of the settlement joints of the outer retaining wall. The exposed section of the grouting anchor rod is positioned in the enlarged foundation so that the grouting anchor rod is effectively connected with the enlarged foundation.

S3, constructing an outer retaining wall on the upper portion of the outer retaining wall foundation. The outer retaining wall is preferably a balanced retaining wall to improve its self-stability. The outer retaining walls are provided with settlement joints at intervals, for example, the outer retaining walls are provided with settlement joints according to a section of 6-8 m, namely, the length of each section of the outer retaining wall is 6-8 m. The external baffle wall is cast in situ, for example, C20 concrete, and the wall height is 2-5 m. In order to facilitate the drainage of the backfill roadbed at the inner side of the outer retaining wall, the outer retaining wall is also provided with at least one water leakage hole. The drain holes are arranged obliquely outwards so as to facilitate drainage, and the drain holes can be formed by embedding pipelines before pouring of the outer retaining wall.

S4, backfilling the inner side of the outer baffle wall to form a backfill roadbed. The backfill should be backfilled and compacted in layers to reduce sedimentation. The backfill roadbed is provided with a reverse filtering layer at the inner side of the outer retaining wall, and the reverse filtering layer corresponds to the water discharge hole of the outer retaining wall so as to effectively discharge accumulated water.

S5, constructing anchoring parts in the bedrock roadbed at the inner side of the backfill roadbed. The anchoring piece is mainly used for anchoring the road panel, has the effect of reinforcing the bedrock roadbed, and can be selected from anchor rods or anchor ropes. The anchor members are preferably uniformly arranged in rows and columns. The anchors are preferably arranged vertically according to the stress of the anchors. The anchor reserves an exposed section which is used for being connected with the road panel.

S6, constructing a road panel on the upper parts of the backfill roadbed and the bedrock roadbed, wherein the upper ends of the anchoring pieces are connected with the road panel.

The road panels are rigid structures, typically reinforced concrete structures. The thickness, concrete strength and reinforcement of the road panel are comprehensively calculated and determined according to the road grade, the road surface width and the automobile load. For example, according to the stress of the road panel, the reinforcement of the road panel comprises transverse reinforcement bars, longitudinal reinforcement bars and stirrups, the transverse reinforcement bars and the longitudinal reinforcement bars are arranged in a double-layer manner, and the upper ends of the anchoring pieces are connected with the reinforcement of the road panel to anchor the road panel to the bedrock roadbed.

The road panel is of an overhanging structure, and a half-width overhanging structure is generally adopted, namely the width of the backfill roadbed is equal to the width of the bedrock roadbed, and the boundary line of the backfill roadbed and the bedrock roadbed corresponds to the central line of the road. The road panel is directly constructed on the upper parts of the backfill roadbed and the bedrock roadbed, and the graded broken stone subbase layer and the cement stabilized broken stone base layer are not constructed.

The road panels are spliced to form a road surface along the road direction, the spliced seams are transverse seams, and the transverse seams are sedimentation seams. In order to adapt to the uneven settlement of the foundation of the outer retaining wall, the settlement joint between two adjacent road panels corresponds to the settlement joint of the outer retaining wall. The road panel is not provided with longitudinal slits arranged in the road direction. When the length of the single road panel is larger, at least one transverse seam is arranged at the part of the road panel, which is positioned on the backfill roadbed, and no transverse seam is arranged at the part of the road panel, which is positioned on the bedrock roadbed, wherein the length direction is consistent with the longitudinal direction of the road, and the width direction is consistent with the transverse direction of the road. The transverse seam between the transverse seam and the road panel is a false seam without a transmission rod, and the longitudinal steel bars of the road panel are cut off at the positions of the transverse seam and the transverse seam.

The construction method of the rock slope overhanging type road structure has the same beneficial effects as the rock slope overhanging type road structure. The construction method of the rock slope overhanging type road structure does not construct a high retaining wall, can construct a shorter outer retaining wall at the upper part of a pile body without constructing a pile foundation, is continuous in construction, can ensure half-width traffic, is simple and convenient in construction, low in safety risk, short in construction period and saves investment.

The invention also provides a settlement treatment method of the rock slope overhanging road structure, which is used for treating the settlement of the rock slope overhanging road constructed by the construction method of the rock slope overhanging road structure, wherein the part of the road panel corresponding to the backfill roadbed is reserved or provided with a grouting hole, and when the backfill roadbed is settled, grouting is carried out through the grouting hole.

Further is: the grouting holes of the road panel are plugged by the temporary plugging body, the grouting holes are opened before grouting, and the grouting holes are closed after grouting. For example, the temporary blocking body is clay.

The settlement treatment method of the rock slope overhanging road structure has the beneficial effects that: the foundation bed is utilized to anchor the road panel, the road panel adopts a cantilever structure, and even if the road is close to the ditch side or the river side, namely, the settlement occurs on the side corresponding to the backfill bed of the road, the backfill bed can be timely grouted and reinforced, the road is not broken, the safety is ensured, the construction is simple and efficient, and the operability is strong.

Drawings

FIG. 1 is a schematic cross-sectional view of a rock ramp overhanging roadway structure of the present invention.

Fig. 2 is a partial enlarged view of fig. 1.

Fig. 3 is a schematic surface view of a rock slope overhanging road structure of the present invention after two road panels are spliced.

Fig. 4 is a cross-sectional view of fig. 3 taken along the direction A-A.

Reference numerals: the outer retaining wall 1, the road panel 2, the backfill roadbed 3, the anchoring piece 4, the grouting hole 5, the grouting anchor rod 6, the cushion layer 7, the enlarged foundation 8, the transverse seam 9 and the transverse seam 10; side ditch 11, roadbed slope 12, road center line 13, natural slope or bedrock surface 14, pile outer boundary 15, temporary support surface 16, guardrail 17.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

The first subject of the invention is a rocky slope overhanging road structure. As shown in fig. 1 and 2, the rock slope overhanging road structure comprises an outer retaining wall 1 and a road panel 2, wherein the bottom of the outer retaining wall 1 is an outer retaining wall foundation, the inner side of the outer retaining wall 1 is a backfill roadbed 3, one side of the backfill roadbed 3 opposite to the outer retaining wall 1 is a bedrock roadbed, and the backfill roadbed 3 and the upper part of the bedrock roadbed are the road panel 2.

The outer retaining wall foundation is used for bearing the outer retaining wall 1, and the outer retaining wall foundation does not need to adopt a pile foundation with complex construction technology. Referring to fig. 1 and 2 for example, the exterior wall foundation includes a consolidated body obtained by laying grouting anchors 6 on the piled body and grouting, a bedding layer 7 laid on top of the consolidated body, and an enlarged foundation 8 laid on top of the bedding layer 7. The grouting anchors 6 are arranged in a plurality of columns, for example, 2 to 3 columns, along the longitudinal direction of the road, the length of the grouting anchors 6 is generally 3 to 4m, and the upper ends of the grouting anchors 6 are positioned in the enlarged foundation 8. To facilitate grouting, the grouting anchor 6 is a self-advancing hollow grouting anchor, for example, the model A25 or A32. The cushion layer 7 plays a role in leveling and caulking grouting. The outer retaining wall 1 is positioned at the upper part of the enlarged foundation 8, and the plane size of the enlarged foundation 8 is larger than the bottom size of the outer retaining wall 1, so that the effect of dispersing stress is achieved.

The outer retaining wall 1 forms a shoulder. In order to improve the self-stability of the outer retaining wall 1, the outer retaining wall 1 is a balanced retaining wall. In order to drain accumulated water in the backfill roadbed 3 at the inner side of the outer retaining wall 1, the outer retaining wall 1 is provided with a water drain hole, and the water drain hole can be formed by embedding a PVC pipe in the outer retaining wall 1. The backfill roadbed 3 is provided with a reverse filtering layer at the inner side of the outer baffle wall 1, and the reverse filtering layer is used for being matched with the water discharge hole. In order to adapt to the uneven settlement of the outer retaining wall foundation, the outer retaining wall 1 is also provided with settlement joints at intervals, and the enlarged foundation 8 is also provided with settlement joints at positions corresponding to the settlement joints of the outer retaining wall 1.

An anchor 4 is arranged in the bedrock roadbed, and the upper end of the anchor 4 is connected with the road panel 2. The road panel 2 is anchored on the bedrock roadbed, and when the backfill roadbed 3 subsides, the road panel 2 is overhanging. In order to facilitate settlement of the outer retaining wall 1 and the backfill roadbed 3, grouting holes 5 are formed in the corresponding portions of the road panel 2 and the backfill roadbed 3, see fig. 3. The grouting holes 5 are provided in plurality and are preferably uniformly arranged in rows and columns. In order to prevent rainwater from flowing into the backfill roadbed 3 from the grouting holes 5, temporary blocking bodies, such as clay, are arranged in the grouting holes 5. At ordinary times, the grouting holes 5 are blocked, when grouting is needed, temporary blocking bodies in the grouting holes 5 are drawn out for grouting, the temporary blocking bodies are used for sealing the grouting holes 5 after grouting, and repeated backfill grouting can be realized.

The road deck 2 is a rigid structure, typically a reinforced concrete structure. The inside of the road panel 2 is a side ditch 11, one side of the side ditch 11 is a roadbed side slope 12 obtained by excavation, the outside of the road panel 2 is a guardrail 17, and the guardrail 17 is arranged at the top of the outer baffle wall 1. According to the stress of the road panel 2, the reinforcement of the road panel 2 includes transverse reinforcement, longitudinal reinforcement and stirrups, which are all arranged in double layers, see fig. 4. The upper ends of the anchors 4 are connected to the reinforcement of the road panel 2, thereby firmly anchoring the road panel 2 to the bedrock subgrade. The anchoring piece 4 is an anchor rod or an anchor rope, for example, the anchoring piece 4 is a cement mortar anchor rod with the model number of C22 or C25, and the length of the anchor rod is 3-4 m. The anchors 4 are uniformly arranged in a plurality of parallel rows, for example, the anchors 4 are provided in at least two rows in the longitudinal direction of the road. The anchors 4 are preferably arranged vertically, depending on the stress of the anchors 4, and for ease of construction.

The road panel 2 is not provided with longitudinal slits arranged in the road direction, based on the stress structure of the road panel 2 and the consideration of allowing deformation. When the length of the single road panel 2 is small, the road panel 2 may be a whole without parting; when the length of the single road panel 2 is large, at least one transverse seam 9 is arranged on the part of the road panel 2 positioned on the backfill roadbed 3, and the transverse seam 9 is not arranged on the part of the road panel 2 positioned on the bedrock roadbed. The longitudinal direction of the road panel 2 corresponds to the longitudinal direction of the road, and the width direction of the road panel 2 corresponds to the transverse direction of the road. Each road panel 2 is spliced end to end along the longitudinal direction of the road to form the road, the splicing seam between two adjacent road panels 2 is a transverse seam 10, and the transverse seam 10 is a settlement seam and corresponds to the settlement seam of the outer retaining wall 1. For example, the outer retaining wall 1 is provided with settlement joints at intervals of 6-8 m, the length of the individual road panels 2 is also 6-8 m, and each road panel 2 is provided with a transverse joint 9, as shown in fig. 3. The transverse joint 10 between the transverse joint 9 and the road panel 2 is a false joint without a transmission rod, and the part of the false joint close to the road surface is filled with joint compound, as shown in fig. 4, and the longitudinal steel bars of the road panel 2 are cut off at the position of the transverse joint 9.

The second subject of the invention is a method for constructing a rock slope overhanging road structure, which is the method for constructing the first subject. The construction method of the rock slope overhanging type road structure comprises the following steps:

s1, excavating the pile body to form a foundation of the construction outer retaining wall foundation.

The pile body is a slope deposit or backfill gravelly soil, the position of the external retaining wall 1 at the outer side of the road is excavated downwards from the top elevation of the road surface by 2 m-5 m according to the actual condition of the site, the temporary excavation slope ratio at the inner side is not steeper than 1:1, the outer side can be excavated by slope laying, the outer side can be excavated in a sweeping manner, the excavation mode is determined according to the external width and the combination of safety and economic requirements, and the width of the substrate is 2 m-3 m. In order to ensure safety, concrete spraying support can be performed on the inner temporary excavation face to form a temporary support face 16.

S2, constructing an outer retaining wall foundation on the excavated and formed substrate. The outer retaining wall foundation is used for bearing the outer retaining wall 1, and a scheme for obtaining the outer retaining wall foundation through grouting is provided below, wherein the scheme comprises S2.1-S2.3.

And S2.1, arranging a grouting anchor rod 6 on a substrate, grouting, and reserving an exposed section of the grouting anchor rod 6. For example, 2-3 rows of self-feeding hollow grouting anchors are vertically distributed on a substrate according to a quincuncial shape with a spacing of 100cm, the type of each grouting anchor 6 is A25 or A32, each length L=3-4 m, and slurry is prepared and grouting is carried out according to the ratio of water to ash=1:1. And grouting according to the actual requirement, and limiting grouting according to the grouting amount of each grouting anchor rod 6, wherein the grouting amount of each grouting anchor rod 6 is 400 kg-600 kg. The upper end of the grouting anchor 6 is exposed 30cm as a connecting part.

S2.2 the mat 7 is applied to the substrate and leveled. The thickness of the cushion layer 7 is 10-20 cm, fine stone concrete with high slump and good workability, such as C20 fine stone concrete, can be adopted, and the cushion layer 7 also has the function of further caulking grouting.

S2.3, constructing an enlarged foundation 8 on the upper part of the cushion layer 7.

The width of the enlarged foundation 8 is determined according to the bottom width of the outer wall 1, and is generally enlarged by 50cm to 100cm on the inner side and the outer side of the outer wall 1, respectively. The width of the enlarged footing 8 is typically 2-4 m and about 50cm thick. In order to adapt to uneven settlement, the expanded foundation 8 is provided with parting joints at the positions of the settlement joints of the outer baffle wall 1. The exposed section of the grouting anchor 6 is positioned in the enlarged base 8 so that the grouting anchor 6 is effectively connected with the enlarged base 8.

S3, constructing an outer retaining wall 1 on the upper part of the outer retaining wall foundation. The outer retaining wall 1 is preferably a counter-balanced retaining wall to improve its self-stability. The outer retaining wall 1 is provided with settlement joints at intervals, for example, the outer retaining wall 1 is provided with settlement joints according to a section of 6-8 m. The balance weight type retaining wall is cast in situ, for example, C20 concrete, and the wall height is 2-5 m. In order to facilitate the drainage of the backfill roadbed 3 inside the outer retaining wall 1, the outer retaining wall 1 is also provided with a drainage hole. In order to facilitate construction, the drain hole is obtained by embedding the pipe fitting before pouring the outer retaining wall 1.

S4, backfilling the inner side of the outer baffle wall 1 to form a backfill roadbed 3. The backfill bed 3 should be backfilled and compacted in layers to reduce sedimentation. The backfill roadbed 3 is provided with a reverse filtering layer at the inner side of the outer retaining wall 1, and the reverse filtering layer corresponds to the water discharge hole of the outer retaining wall 1 so as to effectively discharge accumulated water.

The above S1 to S4 are the construction of the outer retaining wall 1, and the following S5 to S6 are the construction of the road panel 2.

S5, constructing anchoring pieces 4 in the bedrock roadbed inside the backfill roadbed 3.

The anchoring member 4 is mainly used for anchoring the road panel 2, and can be an anchor rod or an anchor cable. The anchor members 4 are a plurality, preferably arranged in rows and columns. The anchors 4 are preferably arranged vertically according to the stress of the anchors 4, the anchors 4 being reserved for exposed segments so that the anchors 4 are effectively connected with the road panel 2. For example, the bedrock roadbed on the mountain side of the road is vertically downwards provided with at least 2 rows of anchor rods at intervals of 100cm in the longitudinal direction and the transverse direction, the anchor rods are exposed 30cm for forming effective connection with the road panel 2, and the anchor rods are C22 or C25 cement mortar anchor rods with the length of 3-4 m.

S6, constructing a road panel 2 on the backfill roadbed 3 and the upper part of the bedrock roadbed, and connecting the upper ends of the anchoring pieces 4 with the road panel 2.

The road panel 2 is of a reinforced concrete structure, and the thickness, the concrete strength and the reinforcement of the road panel 2 are comprehensively calculated and determined according to the road grade, the road surface width and the automobile load. The road panel 2 is preferably designed with half-width overhanging, i.e. the boundary between the backfill bed 3 and the bedrock bed at the road panel 2 corresponds substantially to the road centre line 13. According to the stress of the road panel 2, the reinforcement of the road panel 2 comprises transverse steel bars and longitudinal steel bars, the transverse steel bars and the longitudinal steel bars are arranged in a double-layer mode, the upper ends of the anchoring pieces 4 are connected with the reinforcement of the road panel 2, and the road panel 2 is anchored on a bedrock roadbed. For example, the strength of the road panel 2 is not lower than C35, the thickness is 30-75 cm, the transverse steel bars C25@200 (250) mm are longitudinally and bilaterally arranged along the road, the longitudinal steel bars C16@200 (250) mm are longitudinally and bilaterally arranged along the road, and the A8 stirrups are arranged according to the transverse spacing of 400 (500) mm and the longitudinal spacing of 200 (250); the longitudinal steel bars are cut off at the parting position, and the thickness of the net protective layer of the transverse steel bars and the longitudinal steel bars is 50mm.

The road panel 2 is directly constructed on the backfill roadbed 3 and the upper part of the bedrock roadbed without constructing a graded broken stone subbase layer and a cement stabilized broken stone base layer. The road panels 2 are spliced to form a road surface along the road direction, the spliced seams are transverse seams 10, and the transverse seams 10 are also settlement seams. In order to adapt to the uneven settlement of the foundation of the outer retaining wall, the settlement joint between two adjacent road panels 2 corresponds to the settlement joint of the outer retaining wall 1. For example, a road panel 2 is provided every 6 to 8m along the road direction, and the corresponding outer barrier 1 is provided with a settlement joint every 6 to 8m. Referring to fig. 3, the road panel 2 is not provided with longitudinal slits arranged along the longitudinal direction of the road, when the length of the single road panel 2 is larger, the part of the road panel 2 positioned on the backfill roadbed 3 is provided with at least one transverse slit 9, and the part of the road panel 2 positioned on the bedrock roadbed is not provided with the transverse slit 9, that is, the ditch side of the road panel 2 is provided with the transverse slit 9, and the mountain side is not split. For example, referring to fig. 3, each road panel 2 has a length (in the longitudinal direction of the road) of 6 to 8m, and each road panel 2 is provided with a transverse slit 9. The transverse seam 10 between the transverse seam 9 and the road panel 2 is a false seam without a transmission rod, as shown in fig. 4, the upper part of the false seam is filled with joint compound, such as mastic asphalt, the lower part of the false seam is directly spliced, and the longitudinal steel bars of the road panel 2 are cut at the position of the transverse seam 9.

The third subject of the invention is a settlement treatment method of a rock slope overhanging road structure, which is used for treating the settlement of the rock slope overhanging road structure obtained by constructing according to the second subject, wherein a grouting hole 5 is reserved or formed in the part of the road panel 2 corresponding to the backfill roadbed 3, and grouting is carried out through the grouting hole 5 when the backfill roadbed 3 is settled. The grouting holes 5 are plugged by temporary plugging bodies at ordinary times, the grouting holes 5 are opened before grouting, and the grouting holes 5 are closed after grouting. The number of rows and columns of the grouting holes 5 can be reasonably adjusted according to the actual width of the roadbed, for example, four rows of grouting holes 5 with the diameter of 100mm are reserved on the road panel 2 along the longitudinal direction of the road, the hole spacing is arranged in a rectangular shape with the transverse direction of 100cm and the longitudinal direction of 200cm, the distance from the grouting holes 5 to the outer edge of the road panel is more than or equal to 50cm, and the distance from the grouting holes 5 to the adjacent transverse seams 9 or 10 is arranged in a rectangular shape with the distance of 50-100 cm. The grouting holes 5 are preferably embedded with PVC pipes when the road panel 2 is poured, and care should be taken to avoid the reinforcement of the road panel 2. At ordinary times, the grouting holes 5 are filled with clay in a backfilling manner, when grouting is needed, the clay is drawn out for grouting, and the clay is used for sealing and filling after grouting, so that the aim of repeated backfilling grouting can be fulfilled.

The invention is in accordance with the principle of economy and rationality, does not build an outer balance weight type retaining wall according to the prior art, does not adopt an outer baffle form such as a pile foundation joist retaining wall or a pile plate wall, and provides a scheme which fully recognizes and fully utilizes the properties of a pile body and bedrock, can adapt to backfill deformation, can keep through even if deformed, can strengthen a road and does not produce a safety accident.

Claims (10)

1. The construction method of the rock slope overhanging type road structure is characterized by comprising the following steps of: comprising the following steps:

s1, excavating a pile body to form a substrate for constructing an external retaining wall foundation;

s2, constructing an outer retaining wall foundation on the substrate;

s3, constructing an outer retaining wall (1) on the upper part of the outer retaining wall foundation;

s4, backfilling the inner side of the outer baffle wall (1) to form a backfilled roadbed (3);

s5, constructing anchoring parts (4) in the bedrock roadbed at the inner side of the backfill roadbed (3);

s6, constructing a road panel (2) on the backfill roadbed (3) and the upper part of the bedrock roadbed, and connecting the upper ends of the anchoring pieces (4) with the road panel (2).

2. The method for constructing a rocky slope overhanging road structure according to claim 1, characterized in that: s2 comprises S2.1-S2.3:

s2.1, arranging a grouting anchor rod (6) on a substrate, grouting, and reserving an exposed section of the grouting anchor rod (6);

s2.2, constructing a cushion layer (7) on the substrate and leveling;

s2.3, constructing an enlarged foundation (8) on the upper part of the cushion layer (7).

3. The method for constructing a rocky slope overhanging road structure according to claim 1, characterized in that: the outer retaining wall (1) in the S3 is a counter weight retaining wall.

4. The method for constructing a rocky slope overhanging road structure according to claim 1, characterized in that: the outer baffle wall (1) in the S3 is provided with at least one water discharge hole, and the backfill roadbed (3) in the S4 is provided with a reverse filtering layer at the inner side of the outer baffle wall (1).

5. The method for constructing a rocky slope overhanging road structure according to claim 1, characterized in that: the road panel (2) in the S6 is of a reinforced concrete structure, the reinforcement of the road panel (2) comprises transverse reinforcing steel bars, longitudinal reinforcing steel bars and stirrups, the transverse reinforcing steel bars and the longitudinal reinforcing steel bars are arranged in a double-layer mode, the anchoring pieces (4) are anchor rods or anchor ropes which are vertically arranged, and the upper ends of the anchoring pieces (4) are connected with the reinforcement of the road panel (2).

6. A method of constructing a rocky slope overhanging roadway structure according to any one of claims 1 to 5, characterized in that: the outer retaining wall (1) in the S3 is provided with a settlement joint, and the transverse joint between two adjacent road panels (2) in the S6 is the settlement joint and corresponds to the settlement joint of the outer retaining wall (1).

7. The method for constructing a rocky slope overhanging road structure according to claim 6, wherein: and S6, the road panel (2) is not provided with longitudinal slits arranged along the road direction, at least one transverse slit (9) is arranged at the part of the road panel (2) positioned on the backfill roadbed (3), and the transverse slit (9) is not arranged at the part of the road panel (2) positioned on the bedrock roadbed.

8. The method for constructing a rocky slope overhanging road structure according to claim 7, wherein: the transverse joints between the transverse joints (9) and the road panel (2) are false joints without a transmission rod.

9. The settlement treatment method of the rock slope overhanging type road structure is characterized by comprising the following steps of: the settlement of the rock slope overhanging type road structure obtained by the construction according to any one of claims 1 to 8 is treated, grouting holes (5) are reserved or formed in the part of the road panel (2) corresponding to the backfill roadbed (3), and grouting is carried out through the grouting holes (5) when the backfill roadbed (3) is settled.

10. The settlement treatment method for the rocky slope overhanging road structure according to claim 9, wherein: the grouting holes (5) of the road panel (2) are plugged by temporary plugging bodies, the grouting holes (5) are opened before grouting, and the grouting holes (5) are closed after grouting.

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