CN112982053A

CN112982053A - Frozen soil variable-rigidity road and bridge transition structure and construction process thereof

Info

Publication number: CN112982053A
Application number: CN202110322046.5A
Authority: CN
Inventors: 李双洋; 游甜甜; 杨佳乐; 赵永春; 姜琪
Original assignee: Northwest Institute of Eco Environment and Resources of CAS
Current assignee: Northwest Institute of Eco Environment and Resources of CAS
Priority date: 2021-03-25
Filing date: 2021-03-25
Publication date: 2021-06-18

Abstract

The application provides a frozen soil variable-rigidity road and bridge transition structure and a construction process thereof. The roadbed comprises a graded broken stone cushion layer, a reinforced concrete retaining wall, a broken stone filler layer, a soil filling layer and a rigid lapping plate. The reinforced concrete retaining wall is provided with a plurality of filling areas, and the reinforced concrete retaining wall is connected with the abutment. The rubble-filled layer is arranged in the plurality of filling areas, a slope is arranged on one side of the rubble-filled layer, which is far away from the graded rubble cushion layer, and the height of the slope is gradually reduced from one side close to the abutment to the side far away from the abutment; the rigid butt strap is carried by the broken stone packing layer and is connected with the abutment. The variable-rigidity roadbed design is adopted to improve the differential compaction settlement damage of the roadbed caused by the sudden change of rigidity under the action of long-term dynamic load, the cooling effect of the broken stone packing layer is utilized to prevent the permafrost foundation from melting, the problem of bumping at the bridge head is effectively improved, and the durability of road engineering is improved.

Description

Frozen soil variable-rigidity road and bridge transition structure and construction process thereof

Technical Field

The invention relates to the field of road and bridge construction, in particular to a frozen soil variable-rigidity road and bridge transition structure and a construction process thereof.

Background

Frozen earth is a rock of earth that is below 0 ℃ and contains partially frozen water. The total area of frozen soil (seasonal frozen soil and permafrost) accounts for about 75% of the area of Chinese territory, and the construction of infrastructure such as a plurality of roads, bridges and the like in permafrost areas becomes an indispensable development means. However, the properties of the frozen soil are closely related to the temperature change, the unfrozen water content of the frozen soil changes along with the change of the external environment temperature, and the characteristics determine that the mechanical and thermal properties of the frozen soil have stronger dynamic property and instability, so that the roadbed of the road engineering is easy to be unstable, and further serious engineering diseases are caused. For the transition section of the road and bridge, the phenomenon of vehicle jumping at the bridge head caused by uneven settlement and cracking of the road surface frequently occurs, the driving safety and the road surface traffic capacity are seriously influenced, meanwhile, the degradation of an abutment, a support and the like is accelerated by the impact load caused by bumping of the abutment, and the service life of the road is shortened.

Researches show that the prior frozen soil variable-rigidity road and bridge transition structure has the following defects:

the variable rigidity requirement and the roadbed stability of the transition section roadbed can not be simultaneously met, and the frozen soil foundation layer can not be protected.

Disclosure of Invention

The invention aims to provide a frozen soil variable-rigidity road and bridge transition structure and a construction process of the frozen soil variable-rigidity road and bridge transition structure, which can meet the variable rigidity requirement of a road and bridge transition section roadbed, ensure the stability of the roadbed, prevent the roadbed from breaking and sliding and have the function of cooling protection on a frozen soil foundation layer.

The embodiment of the invention is realized by the following steps:

in a first aspect, the present invention provides a frozen soil variable stiffness road and bridge transition structure, including:

the bridge abutment and the roadbed are arranged on the foundation layer;

the road bed includes:

the graded broken stone cushion layer is arranged on the ground base layer;

the reinforced concrete retaining wall is arranged on the graded broken stone cushion layer and is provided with a plurality of filling areas which are arranged at intervals in the extending direction of the roadbed; the reinforced concrete retaining wall is connected with the abutment;

the gravel packing layers are arranged in the plurality of filling areas, one side of each gravel packing layer, which is far away from the graded gravel cushion layer, is provided with a slope, and the height of each slope is gradually reduced from one side close to the bridge abutment to the side far away from the bridge abutment;

a fill layer disposed on the slope;

and the rigid butt strap is arranged between the soil filling layer and the abutment, is borne by the broken stone filling layer and is connected with the abutment.

In an alternative embodiment, the reinforced concrete retaining wall comprises a framed wall body including a heel panel and a plurality of first wall panels connected to the heel panel, the plurality of first wall panels decreasing in height in a direction from a side near the abutment to a side away from the abutment, the heel panel and the plurality of first wall panels together defining a plurality of infill areas.

In an optional embodiment, the frame-type wall further comprises two second wall panels with equal height, the two second wall panels are connected with the wall heel plate, the two second wall panels are located on one side, close to the bridge abutment, of the first wall panel with the highest height among the first wall panels, the two second wall panels are spaced in the extending direction of the roadbed, and the second wall panel, far away from the first wall panel, of the two second wall panels is connected with the bridge abutment.

In an optional embodiment, the rubble and lump filler layer comprises a rubble and lump filler layer and a rubble leveling layer, the rubble and lump filler layer is arranged in the plurality of filling areas, and the rubble leveling layer is arranged on the rubble and lump filler layer and is positioned between the two second wall panels;

the rigid butt strap is simultaneously carried by the gravel leveling layer and the two second wall panels.

In an alternative embodiment, a diagonal reinforcement is provided between at least two of the plurality of panels of the framed wall.

In an optional embodiment, the graded broken stone cushion layer comprises a first-level crushed stone cushion layer, a first geogrid layer, a second-level crushed stone cushion layer, a second geogrid layer and a third-level crushed stone cushion layer which are sequentially arranged from bottom to top.

In an optional embodiment, the bridge abutment comprises a foundation, a body and a top, which are sequentially arranged from bottom to top, the foundation is used for being connected with the foundation layer, and the part of the foundation is connected with one side, away from the reinforced concrete retaining wall, of the graded broken stone cushion layer.

In an alternative embodiment, a concrete backfill layer is arranged between the platform foundation and the graded broken stone cushion layer.

In an optional embodiment, the abutment is embedded with a first connecting steel bar, the rigid butt strap is provided with a second connecting steel bar, and the first connecting steel bar is connected with the second connecting steel bar through a threaded sleeve.

In a second aspect, the invention provides a construction process of a frozen soil variable-rigidity road and bridge transition structure, which comprises the following steps:

paving a graded broken stone cushion layer on the foundation layer provided with the abutment;

arranging a reinforced concrete retaining wall with a plurality of filling areas on the graded broken stone cushion layer, wherein the reinforced concrete retaining wall is abutted against the abutment;

arranging a rubble and filled layer in the plurality of filling areas, and enabling one side of the rubble and filled layer, which is far away from the abutment, to form a slope;

arranging a soil filling layer on the slope;

and a rigid butt strap is arranged between the soil filling layer and the abutment and is simultaneously borne by the reinforced concrete retaining wall and the broken stone filler layer, so that the rigid butt strap is fixedly connected with the abutment.

The embodiment of the invention has the beneficial effects that:

in summary, in the frozen soil variable-stiffness road and bridge transition structure provided by this embodiment, the connection between the broken stone filler layer and the filler layer forms a slope structure, so that the bridge abutment at the road and bridge transition is rigidly connected with the roadbed, the stepped compaction settlement caused by the difference in stiffness between the bridge abutment and the roadbed is avoided, and the connection is combined with the rigid butt strap at the abutment back of the bridge abutment, so that the dynamic load of the road surface can be uniformly transferred to the roadbed, the broken or regional compaction of the broken stone filler layer is avoided, and the non-uniform settlement caused by the abrupt change in stiffness and the broken stone compaction effect of the road surface can be effectively prevented under the action of the long-term dynamic load. And, compare in ordinary soil filling layer, the broken stone filler layer can greatly dispel the dynamic stress that produces when the train passes through, reduces the adverse effect to the road bed structure effectively, has increased the stability and the service life of road bed.

Meanwhile, the massive macadam packing layer has good heat shielding and cold exchange effects on the permafrost region foundation, can realize cooling protection on the permafrost foundation, prevents the permafrost foundation from melting and settling, and further improves the problems of subgrade collapse and uneven pavement settlement. Simultaneously, the road bridge changeover portion side sets up the piece rubble filler layer ladder that has the slope structure, has replaced the concrete toper bank protection of road bridge changeover portion in the past, has not only improved the too big, too much problem of heat absorption of concrete panel area, still can reduce the average temperature in the frozen soil foundation through the cooling effect of piece rubble filler layer, realizes the frozen soil protection. Meanwhile, the heat shielding effect of the broken stone packing layer can also prevent the strong water erosion effect of water flow under the bridge on the frozen soil foundation, so that the frozen soil is prevented from being in a long-term unstable state.

And the broken stone filler layer is arranged in a filling area formed by the reinforced concrete retaining wall, and the dynamic load acting on the roadbed is transmitted to the reinforced concrete retaining wall and the broken stone filler layer.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

FIG. 1 is a schematic structural diagram of a frozen soil variable-rigidity road and bridge transition structure according to an embodiment of the invention;

FIG. 2 is a schematic cross-sectional structure view of a frozen soil variable stiffness road and bridge transition structure according to an embodiment of the invention;

fig. 3 is a schematic perspective view of a bridge transition structure according to an embodiment of the present invention;

FIG. 4 is a schematic structural view of a reinforced concrete retaining wall according to an embodiment of the present invention;

FIG. 5 is a partial structural view of a reinforced concrete retaining wall according to an embodiment of the present invention;

FIG. 6 is a schematic structural view of an abutment and a rigid strap according to an embodiment of the present invention;

fig. 7 is a partial structural view showing a connection structure of an abutment and a rigid strap according to an embodiment of the present invention.

Icon:

001-the basement layer; 101-a first carrying surface; 102-a second carrying surface; 100-an abutment; 110-a foundation; 111-loading; 112-setting; 120-a table body; 130-table top; 140-concrete backfill layer; 150-first connecting bars; 160-threaded sleeve; 200-roadbed; 300-graded broken stone cushion layer; 400-reinforced concrete retaining wall; 410-frame type wall; 411-a wall heel plate; 412-a first shingle; 413-a second shingle; 420-counter-pulling the reinforcing steel bars; 430-fill area; 440-grouting sleeve; 441-grouting port; 442-a pulp outlet; 450-reserving reinforcing steel bars; 500-crushed stone packing layer; 510-a ramp; 520-a rock fill layer; 530-gravel leveling course; 600-filling; 700-rigid straps; 710-a second connecting bar; 800-ventilating pipe.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or the orientations or positional relationships that the products of the present invention are conventionally placed in use, and are only used for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 to 7, the embodiment provides a frozen soil variable stiffness road and bridge transition structure, which is not easy to have large-scale settlement during service, high in safety and long in service life.

Referring to fig. 1 and 2, in the present embodiment, the frozen soil stiffness-variable road-bridge transition structure includes a bridge abutment 100 and a roadbed 200, which are disposed on a foundation layer 001, where the foundation layer 001 is the frozen soil foundation layer 001.

The roadbed 200 includes a graded broken stone cushion layer 300 for being disposed on a foundation layer 001, a reinforced concrete retaining wall 400 disposed on the graded broken stone cushion layer 300, a broken stone packing layer 500, a fill layer 600 disposed on a slope 510, and a rigid bridge 700 disposed between the fill layer 600 and the abutment 100. The reinforced concrete retaining wall 400 is provided with a plurality of filling regions 430 arranged at intervals in the extending direction of the roadbed 200, and the reinforced concrete retaining wall 400 is connected with the abutment 100. The rubble packing layer 500 is arranged in the plurality of filling areas 430, a slope 510 is arranged on one side of the rubble packing layer 500, which is far away from the graded rubble cushion layer 300, and the height of the slope 510 is gradually reduced from one side close to the abutment 100 to one side far away from the abutment 100; rigid access panels 700 are carried by the rubble packing 500 and are connected to the abutment 100.

The beneficial effects of frozen soil variable-rigidity road and bridge transition structure that this embodiment provided include, for example:

the frozen soil variable rigidity road and bridge transition structure that this embodiment provided mainly relies on the mode that rubble packing layer 500 and soil filling layer 600 combined together to realize the slow change of road and bridge changeover portion rigidity to rubble packing layer 500 adopts reinforced concrete retaining wall 400 to consolidate, has not only improved rubble packing layer 500 and has easily taken place the problem of lateral sliding under the effect of long-term dynamic load, still reduces ground base 001 through the surface area that reduces concrete slab and absorbs heat, reaches the purpose of protection frozen soil ground base 001 from this. Meanwhile, the frozen soil variable-rigidity road and bridge transition structure prevents a frozen soil foundation from melting and settling by utilizing the cooling effect of the massive crushed stone packing layer 500, further protects permafrost, and effectively solves the problem of bumping at the bridge head caused by uneven settlement of a road surface.

Referring to fig. 1, in the present embodiment, it should be understood that the ground base layer 001 includes two bearing surfaces with a height difference, the two bearing surfaces are both horizontally disposed, the height of the first bearing surface 101 is lower than that of the second bearing surface 102, and the first bearing surface 101 and the second bearing surface 102 are connected by a vertical surface.

Referring to fig. 3, in the present embodiment, before the roadbed 200 is installed, the abutment 100 is first laid on the first bearing surface 101. The abutment 100 comprises a foundation 110, a body 120 and a top 130, which are arranged from bottom to top in sequence, wherein the foundation 110 is used for being connected with the first bearing surface 101 of the foundation layer 001.

Alternatively, the cross section of the table base 110 is "T" shaped, in other words, the table base 110 includes an upper table 111 and a lower table 112, and the width of the upper table 111 in the extending direction of the roadbed 200 is smaller than the width of the lower table 112 in the length direction of the roadbed 200, so that the cross section of the table base 110 is "T" shaped. After the platform base 110 is fixed on the first bearing surface 101, a height difference exists between the lower platform 112 and the second bearing surface 102, and a concrete backfill layer 140 is disposed on one side of the lower platform 112 and the upper platform 111 close to the second bearing surface 102. The top surface of the concrete backfill layer 140 is at the same level as the second bearing surface 102.

The platform body 120 is fixed on the top surface of the upper platform 111, and the first connecting steel bars 150 are embedded in one side of the platform top 130 close to the second bearing surface 102. The first connecting bar 150 is used to connect with the rigid patch 700.

Furthermore, the abutment foundation 110 is made of C50 reinforced concrete, the rest part of the abutment 100 is made of C35 reinforced concrete, the concrete is fed in a through long guide pipe string tube during pouring so as to ensure that the free fall of the concrete is not more than 2m, and the thickness of each layer is not more than 30cm by adopting a layered pouring method, so that the impact of the concrete during pouring is reduced, and the compressive strength of the abutment 100 is ensured.

Referring to fig. 6 and 7, further, a first connecting reinforcement 150 having a length of 1.5m is provided at the right side of the abutment top 130 of the abutment 100 along the extension direction of the roadbed 200 for connecting the rigid access panel 700; the first connecting reinforcing steel bars 150 are phi 8 threaded reinforcing steel bars arranged at intervals of 200 mm; the concrete backfill layer 140 is formed by backfilling C15 plain concrete.

In this embodiment, optionally, the graded broken stone cushion layer 300 is used to be laid on the second bearing surface 102, the thickness of the graded broken stone cushion layer 300 is set to be 50cm, after the graded broken stone cushion layer 300 is laid, the graded broken stone cushion layer 300 is connected with the upper platform 111 and the concrete backfill layer 140, and the top surface of the graded broken stone cushion layer 300 and the top surface of the upper platform 111 are located in the same plane, that is, the top surface of the graded broken stone cushion layer 300 is equal to the top surface of the upper platform 111 in height. The graded broken stone cushion 300 is mainly formed by piling crushed granite which has good water permeability and a particle size of 5-6 cm. The compression strength of the graded crushed stone layer is not less than 80MPa, the crushing value is not less than 35%, the content of weak particles is less than 5%, the content of mud is less than 2%, the content of flat and slender crushed stone is less than 20%, and the compaction coefficient is not less than 0.95.

Further, the graded gravel layer comprises a first-level gravel layer 300, a first geogrid layer, a second-level gravel layer 300, a second geogrid layer and a third-level gravel layer 300 which are sequentially stacked and laid from bottom to top, the first-level gravel layer 300, the second-level gravel layer 300 and the third-level gravel layer 300 are all laid in a mode of mechanical rolling after manual spreading, and the height difference is not larger than +/-15 mm after rolling. The overlapping length of the first geogrid layer and the second geogrid layer is larger than 30cm, the tensile strength is not smaller than 25MPa, and the tensile modulus is not smaller than 650 MPa.

Referring to fig. 4, in the present embodiment, optionally, the reinforced concrete retaining wall 400 includes a frame-type wall 410 and opposite-pulling steel bars 420. The frame-type wall 410 includes a wall heel plate 411 and a plurality of wall panels connected to the wall heel plate 411, the wall panels are perpendicular to the wall heel plate 411, and in the extending direction of the roadbed 200, the distance between adjacent wall panels is equal.

Optionally, the plurality of wall panels comprises a plurality of first wall panels 412 and two second wall panels 413, the height of the plurality of first wall panels 412 gradually decreases in a direction from a side close to the abutment 100 to a side far from the abutment 100, and the heel panel 411 and the plurality of first wall panels 412 together define a plurality of infill areas 430. The two second wall panels 413 are located on one side, close to the bridge abutment 100, of the first wall panel 412 with the highest height among the plurality of first wall panels 412, the two second wall panels 413 have intervals in the extending direction of the roadbed 200, the second wall panel 413, far away from the first wall panel 412, of the two second wall panels 413 is attached and connected with the abutment body 120 of the bridge abutment 100, and the two second wall panels 413 and the wall heel panel 411 jointly define a filling area 430. The heel plate 411 is laid on the graded gravel pad 300 and is connected to a part of the top surface of the upper deck 111.

It will be appreciated that the first wall panel 412 of the plurality of first wall panels 412 which is the lowest in height is spaced from the side of the heel panel 411 remote from the abutment 100, the first wall panel 412 of the lowest in height and the heel panel 411 forming a right triangular infill area 430.

The number of the opposite-pulling steel bars 420 is set as required, and at least one opposite-pulling steel bar 420 is arranged between two adjacent wall panels, thereby enhancing the structural stability of the reinforced concrete retaining wall 400.

Referring to fig. 5, in the embodiment, it should be noted that the reinforced concrete retaining wall 400 is a prefabricated member, and can be prefabricated in a factory and then transported to a site for assembly. For example, the reinforced concrete retaining wall 400 is connected by using the full grouting sleeve 440, i.e. the grouting sleeve 440 is threaded first, then the reserved steel bar 450 to be connected is threaded, the reserved steel bar 450 is connected with the sleeve by a screw thread, and finally the grouting material is poured. It should be understood that the grout sleeve 440 is provided with a grout inlet 441 and a grout outlet 442, and grout is injected from the grout inlet 441.

Further, the wall thickness of wall is set to 160mm according to antidetonation grade second grade requirement for wall heel board 411 and shingle nail, evenly arranges phi 16 screw-thread steel and disposes the stirrup according to interval 200mm in the wall, and level and vertical distribution reinforcing bar arrangement rate is not less than 0.2% to reserve 30cm long reinforcing bar in advance according to the position to lacing wire 420 and so that anchor is connected. The length of the heel plate 411 in the extending direction of the roadbed 200 is 100 m.

Further, adopt Q235 plain steel muscle to the reinforcing bar 420, the diameter is 12mm, and the direction of height arranges according to 1m equidistant, and every row of quantity to reinforcing bar 420 is from supreme degressive gradually down.

In this embodiment, optionally, each of the filling regions 430 is filled with a rubble packing layer 500, and the plurality of rubble packing layers 500 in the plurality of filling regions 430 form a structure having an outer contour substantially in a right trapezoid shape. Wherein, the upper bottom of right trapezoid is away from graded rubble filler bed course, and the lower bottom contacts with wall heel board 411, and optional, the length of upper bottom is 10m, and the length of lower bottom is 100 m. The upper base is formed between the filling areas 430 of the two second wall panels 413 at the same height as the top surfaces of the two second wall panels 413, i.e., the upper base is in the same plane as the top surfaces of the two second wall panels 413, which is used to support the rigid patch 700.

Referring to fig. 3, optionally, the crushed stone filler layer 500 includes a crushed stone filler layer 520 and a crushed stone leveling layer 530, the maximum particle size of the crushed stone filler layer 520 is not more than 150mm, the compacted thickness of each layer is not more than 30cm, the settlement after compaction is less than 3mm, and the porosity is not more than 28%. The thickness of the gravel leveling layer 530 is 20cm, and 5-6cm gravel is filled and compacted. The gravel leveling layer 530 is disposed on the top of the gravel packing layer 520, and the top surface of the gravel leveling layer 530 is the upper bottom of the gravel packing layer 500, that is, the gravel leveling layer 530 is disposed on the top of the gravel packing layer 520 between the two second wall panels 413, and supports the rigid patch 700 together with the second wall panels 413.

In the embodiment, the filling layer 600 adopts mixed soil and sand clay with the fine particle content of less than 30% as filling materials, the maximum compaction thickness of each layer is not more than 20cm, and slope releasing is carried out by adopting a slope ratio of 1: 1.5. After the filling layer 600 is laid, the top surface of the filling layer 600 is higher than that of the gravel leveling layer 530, and a rectangular groove for clamping the rigid butt strap 700 is formed between the filling layer 600 and the table top 130.

In this embodiment, optionally, the length of the rigid access panel 700 is set to 10m, the thickness of the access panel is not less than 30cm, second connection bars 710 with a distance of 200mm and a diameter of 8mm are arranged in the panel, the rigid access panel 700 is disposed on the gravel leveling layer 530 and is in contact with the two second wall panels 413, both sides of the rigid access panel 700 in the extending direction of the roadbed 200 are respectively connected with the terrace top 130 and the fill layer 600, and the second connection bars 710 on the rigid access panel 700 are connected with the first connection bars 150 on the terrace top 130 through the threaded sleeves 160 and are concreted by using C30 concrete.

It should be understood that, at the transition section of the road bridge, the change of the longitudinal slope is small, so that the road surface at the transition section can be approximate to a circular arc, and when a vehicle passes through the circular arc, centripetal acceleration is generated. Assuming that M is the weight of the human vehicle, the centripetal force is F ═ Mv²When mu is 0.1, the automobile is in the critical trip state, and it can be concluded that R is Mv²÷F＝v²Mu g/ug. Further, assuming that the gradient of the rigid access panel 700 is i and the gradient α ≈ i, it can be deduced that the critical vehicle-jumping longitudinal gradient rate of the vehicle is i ═ L/R ═ L/v ≈ L/R ≈ i²It can be seen that the running speed of the vehicle and the length of the rigid access panel 700 both affect the vertical curve radius and the slope rate of the critical vehicle jumping state, the length of the rigid access panel 700 is unchanged, the longitudinal slope rate of the critical vehicle jumping decreases with the increase of the speed, and the vehicle is very likely to jump. Therefore, the length of the rigid access panel 700 should be increased as the grade of the road becomes higher, and generally should not be shorter than 8m, and in this embodiment, the length of the rigid access panel 700 is selected to be 10m to improve the road surface condition and improve the driving safety.

It should be appreciated that after the rigid access panel 700 is positioned, the top surface of the rigid access panel 700 is flush with the top surface of the fill 600.

In other embodiments, a plurality of ventilation pipes 800 are embedded in the rock-fill filler layer 520, the ventilation pipes 800 extend along the width direction of the roadbed 200, and both ends of the ventilation pipes 800 are open.

The frozen soil variable-rigidity road and bridge transition structure provided by the embodiment is high in structural stability, long in service time, safe and reliable.

The embodiment also provides a construction process of the frozen soil variable-rigidity road and bridge transition structure, which comprises the following steps:

A. before the roadbed 200 is worked, three-way leveling is realized, the natural earth surface in the planning range of the roadbed 200 is processed in a rolling mode, measurement and routing work is carried out simultaneously, and the measurement precision is based on the requirement of highway route survey regulations.

B. The first-stage crushed stone cushion layer 300 is paved on the treated natural ground surface in a mode of firstly manually paving and then mechanically compacting, the flatness degree of the graded crushed stone cushion layer 300 is measured to meet the requirements of the technical specification of highway subgrade 200 construction, and then geogrids are paved. And (3) repeating the steps, laying a second-level gravel cushion layer 300 and a third-level gravel cushion layer 300 in sequence from bottom to top, and compacting.

C. After the reinforced concrete retaining wall 400 is transported to a construction site, the reinforced concrete retaining wall is assembled in a threaded sleeve connection mode according to requirements. Earlier along the interior border installation reinforcing bar positioning fixture of prefabricated wall body and fixed seven word, the position that falls of prefabricated subassembly is conveniently guided to whether adopt the mirror to observe the prefabricated subassembly reinforcing bar with grouting sleeve 440 to the hole. After the placement is completed, the perpendicularity of the prefabricated wall body is adjusted through the inclined supports, the inclined supports are fixed, then the inner side of the wall body in the grouting area is plugged at once, it is ensured that plugging mortar reaches the designed strength level before grouting, and meanwhile, pollution to the grouting area is avoided. And (4) after the mortar is blocked for 4 hours, mechanically and continuously grouting, and reserving the test block according to the standard requirement.

D. After the maintenance of the installed reinforced concrete retaining wall 400 is completed, the opposite-pulling steel bars 420 are arranged in the wall panel, and both ends of the opposite-pulling steel bars 420 are respectively connected with the reserved steel bars 450 of the wall panel of the reinforced concrete retaining wall 400 in an anchoring manner.

E. Filling and compacting the broken stone fillers in the reinforced concrete retaining wall 400 layer by layer according to requirements, wherein the compacted thickness of each layer is not more than 30cm, and finally paving a 20 cm-thick broken stone leveling layer 530. The method comprises the steps of conveying a broken stone filler to a construction site, measuring and paying off, manually paving, roughly flattening by using an excavator, then arranging and pressing once by using an excavator crawler, then filling stone gaps with broken stone fine materials by using a loader in cooperation with manual work, and rolling for 4-6 times by using a vibratory roller until a compaction standard is met, and then paving the next layer.

F. The filling layer 600 is filled with the roadbed 200 paved in layers, the paving height of each layer is controlled to be 25cm, and the roadbed is compacted for 5-6 times by a vibratory roller after being subjected to static pressure once by a steel wheel roller. Before each layer of construction, the upper layer of compacted filling soil needs to be sprayed with water for moistening, so that the roadbed 200 is prevented from being damaged, and the dust pollution is reduced.

G. And binding reinforcing steel bars on the upper layer of the rubble roadbed 200, connecting the left side of the rubble roadbed 200 with the reserved reinforcing steel bars 450 through the threaded sleeves 160, then erecting a formwork according to the panel size of the rigid access panel 700, pouring by adopting C30 concrete, and maintaining for 14 days after pouring.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. The utility model provides a frozen soil becomes rigidity road bridge transition structure which characterized in that includes:

the bridge abutment and the roadbed are arranged on the foundation layer;

the roadbed comprises:

the graded broken stone cushion layer is arranged on the foundation layer;

the gravel packing layers are arranged in the plurality of filling areas, a slope is arranged on one side of the gravel packing layer, which is far away from the graded gravel cushion layer, and the height of the slope is gradually reduced from one side close to the abutment to one side far away from the abutment;

a fill layer disposed on the slope;

and the rigid butt strap is arranged between the filling layer and the abutment, is borne by the broken stone packing layer and is connected with the abutment.

2. The frozen soil variable stiffness road and bridge transition structure according to claim 1, characterized in that:

the reinforced concrete retaining wall comprises a frame type wall body, the frame type wall body comprises a wall heel plate and a plurality of first wall panels connected with the wall heel plate, the heights of the first wall panels are gradually reduced from one side close to the bridge abutment to the side far away from the bridge abutment, and the wall heel plate and the first wall panels jointly define a plurality of filling areas.

3. The frozen soil rigidity-variable road and bridge transition structure according to claim 2, characterized in that:

frame-type wall body still includes two second shingles that highly equals, two second shingles all with the wall heel board is connected, two second shingles all are located the first shingle of high height is close to in a plurality of first shingles one side of abutment, two second shingles are in the extending direction of road bed has the interval, keep away from in two second shingles first shingle the second shingle with the abutment is connected.

4. The frozen soil variable stiffness road and bridge transition structure according to claim 3, characterized in that:

the broken stone filler layer comprises a broken stone filler layer and a broken stone leveling layer, the broken stone filler layer is arranged in the plurality of filling areas, and the broken stone leveling layer is arranged on the broken stone filler layer and is positioned between the two second wall panels;

the rigid butt strap is simultaneously carried by the rubble screed and the two second shingles.

5. The frozen soil variable stiffness road and bridge transition structure according to any one of claims 2 to 4, wherein:

and a counter-pulling steel bar is arranged between at least two of the plurality of wall panels of the frame-type wall body.

6. The frozen soil variable stiffness road and bridge transition structure according to claim 1, characterized in that:

the graded broken stone cushion layer comprises a first-level broken stone cushion layer, a first geogrid layer, a second-level broken stone cushion layer, a second geogrid layer and a third-level broken stone cushion layer which are sequentially arranged from bottom to top.

7. The frozen soil variable stiffness road and bridge transition structure according to claim 1, characterized in that:

the abutment includes by supreme platform basis, platform body and the bench top that sets gradually down, the platform basis be used for with the foundation of the ground connects, just the part of platform basis with graded broken stone bed course is kept away from one side of reinforced concrete retaining wall is connected.

8. The frozen soil variable stiffness road and bridge transition structure according to claim 7, characterized in that:

and a concrete backfill layer is arranged between the platform foundation and the graded broken stone cushion layer.

9. The frozen soil variable stiffness road and bridge transition structure according to claim 1, characterized in that:

the abutment is pre-buried with first connecting reinforcement, the rigidity access plate is equipped with the second connecting reinforcement, first connecting reinforcement with the second connecting reinforcement passes through threaded sleeve and connects.

10. A construction process of a frozen soil variable-rigidity road and bridge transition structure is characterized by comprising the following steps:

arranging a rubble filler layer in the filling areas, and enabling one side, far away from the abutment, of the rubble filler layer to form a slope;

arranging a soil filling layer on the slope;

the soil filling layer with set up the rigidity attachment strap between the abutment, the rigidity attachment strap quilt simultaneously reinforced concrete props up the barricade and the piece rubble packing layer bears, will the rigidity attachment strap with abutment fixed connection.