CN217782100U - Full-section cofferdam access way structure of river-crossing underground tunnel - Google Patents

Abstract

The utility model relates to a cross full-section cofferdam pavement structure in buried tunnel of river, its constitution includes: the construction cofferdam is formed on the double-layer steel plate pile system; geotextiles are arranged at the bottom and the outer side of the construction cofferdam, cohesive soil is filled in layers, and a waterproof membrane is laid; a pit construction access road is filled in the construction cofferdam; the in-pit construction access road sequentially comprises bottom geotextile, backfilled cohesive soil, broken stone and reinforced concrete from bottom to top; the side of the construction cofferdam facing the river is piled with a woven sandbag. The full-section cofferdam pavement of the river-crossing underground tunnel has the advantages of good structural stability, high safety, high construction speed and good economic benefit.

Description

Full-section cofferdam pavement structure of river-crossing underground tunnel

Technical Field

The utility model provides a cross full-section cofferdam pavement structure in river buried tunnel, concretely relates to open cut method cross full-section cofferdam construction technology in river buried tunnel.

Background

In an increasingly congested city, how to utilize underground space to the maximum extent and exert the function of an underground structure becomes an important content of municipal infrastructure construction. Underground structures such as urban tunnels and comprehensive pipe galleries are gradually favored by engineers because underground space construction can be fully utilized. When the buried tunnel is constructed by the open cut method, the buried tunnel is mostly a deep foundation pit and the excavation surface is large, and particularly when river-crossing construction is carried out, the situation that a river channel is deep and is a deep sludge riverbed is often met, higher requirements are provided for a riverbed cofferdam and a deep foundation pit supporting structure, the construction difficulty is large, and the safety risk is large.

SUMMERY OF THE UTILITY MODEL

In order to solve the problem, the utility model provides a cross full-section cofferdam pavement structure of river buried tunnel, the mesh is when overcoming the tunnel open cut method of crossing the river and carrying out cofferdam construction, and tunnel major structure deep basal pit excavation face is big and passes through the characteristics of deep silt matter riverbed, and its stability is good, the security is high, construction speed is fast, economic benefits is good.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

a full-section cofferdam access way structure of a river-crossing underground tunnel comprises a construction cofferdam formed by enclosing channel steel, wherein at least one group of steel sheet piles which are oppositely arranged inside and outside are inserted into the channel steel, and the steel sheet piles which are oppositely arranged inside and outside are connected through a horizontal connecting beam to form a stable double-layer steel sheet pile system; geotextile is laid at the bottom of the area of the construction cofferdam between the channel steels, cohesive soil layers are filled on the geotextile, and waterproof membranes are arranged between the cohesive soil layers; and a construction sidewalk is filled in the construction cofferdam, and woven sandbags are piled at the side of the construction cofferdam close to the river.

Preferably, the in-pit construction pavement is composed of geotextile, a cohesive soil layer, a crushed stone layer and a reinforced concrete layer from bottom to top.

Preferably, the steel sheet piles arranged oppositely inside and outside are connected through split bolts.

Preferably, the filling height of the area of the construction cofferdam between the channel steels is 0.5-1.0 m above the highest water level of the river, and the slope is processed by slope releasing at a ratio of 1.

Preferably, the thickness of the waterproof membrane is 0.5mm.

Preferably, the stacking height of the woven sandbag is 1m, and the woven sandbag is used for temporary protection.

Preferably, the upper layer of the cohesive soil layer is provided with a geotextile layer.

Preferably, the bottom of the construction cofferdam construction access road is backfilled by adopting cohesive soil filling materials.

The utility model discloses following beneficial effect has:

(1) The utility model provides a cross the full section cofferdam pavement in river buried tunnel structural stability is good, and the security is high. A double-layer steel sheet pile cofferdam is adopted, and double-layer steel sheet piles are fixed into a stable double-layer steel sheet pile system through split bolts. The cofferdam is high in anti-seepage capability and good in anti-seepage effect by filling the core with cohesive soil and laying geotextile and waterproof membrane, so that the stability of a double-layer steel sheet pile system and the bearing capacity of the base of the constructed cofferdam are improved, and the constructed cofferdam has higher safety.

(2) The utility model provides a cross the full section cofferdam pavement structure construction speed in the buried tunnel of river fast, economic benefits is good. The double-layer steel sheet pile cofferdam adopts a sidewalk filling advance method, firstly utilizes the construction cofferdam to pump water and desilt in the cofferdam, and finally carries out double-layer steel sheet pile construction cofferdam construction, the inserting and the dismounting of the steel sheet piles are efficient, and the construction speed is high.

Drawings

FIG. 1 is a structural diagram of a full-section cofferdam pavement of a river channel of the utility model;

FIG. 2 is a flow chart of a construction process of a full-section cofferdam access way structure of a river-crossing underground tunnel;

the construction method comprises the following steps of 1, riverbed, 2, construction cofferdam, 3, steel sheet pile, 4, geotextile, 5, waterproof membrane, 6, cohesive soil, 7, split bolts, 8, weir crest, 9, woven sand bag, 10, construction access in pit and 11, foundation pit enclosure.

Detailed Description

The following describes the embodiments of the present invention in detail with reference to fig. 1.

Example 1

Referring to fig. 1, the utility model provides a full-section cofferdam pavement structure of river-crossing underground tunnel, which comprises a construction cofferdam 2 formed by enclosing channel steel, a set of steel sheet piles 3 arranged oppositely inside and outside are inserted and punched on the channel steel, and the steel sheet piles 3 arranged oppositely inside and outside are connected through a horizontal connecting beam 7 to form a stable double-layer steel sheet pile system; geotextile 4 is laid at the bottom of the area of the construction cofferdam between the channel steels, a cohesive soil layer 6 is filled on the geotextile 4, and a waterproof membrane 5 is arranged on the cohesive soil layer 6; and a construction sidewalk 10 is filled in the construction cofferdam 2, and a woven sand bag 9 is piled at the side of the river-facing side weir of the construction cofferdam (2).

As shown in fig. 1, the in-pit construction pavement 10 is composed of geotextile, a cohesive soil layer, a crushed stone layer and a reinforced concrete layer from bottom to top, and thus a construction passage is formed.

In the present embodiment, the steel sheet piles 3 disposed opposite to each other inside and outside are connected by the split bolts 7.

As shown in figure 1, the filling height of the area of the construction cofferdam between the channel steels is 0.5-1.0 m above the highest water level line 1 of the river channel, and the slope is processed by adopting a slope releasing mode of 1.

In this embodiment, the thickness of the waterproof film is 0.5mm.

In the embodiment, the stacking height of the woven sandbag (9) is 1m, and the woven sandbag is used for temporary protection.

In this embodiment, the topsoil layer, i.e., the weir crest 8, is provided with a geotextile layer.

In addition, the bottom of the construction cofferdam construction sidewalk is backfilled by adopting cohesive soil filler.

Example 2

Exemplarily, please refer to fig. 2, and the embodiment also provides a construction process of a full-section cofferdam access way structure of a river-crossing underground tunnel, comprising the following steps:

step one, construction preparation. (1) The drawings are familiar and reviewed, and design content and design intention are known; (2) Measuring and lofting according to a drawing and a working surface, and determining a position area of a construction cofferdam; determining storage point positions of supporting temporary structures such as steel sheet piles and the like; (3) Checking, measuring, classifying and numbering construction cofferdams such as steel sheet piles and foundation pit supporting materials, and stacking the construction cofferdams and the foundation pit supporting materials in layers according to the pile inserting sequence; preparing a construction cofferdam protection foot back pressure woven sand bag throwing bag.

And step two, constructing a cofferdam in advance. And (4) discharging the point positions required by the construction cofferdam filling according to the design requirements, and obviously marking by using bamboo sticks. And backfilling and compacting by using cohesive soil in a layered manner, and paving a waterproof membrane with the thickness of 0.5mm in the construction cofferdam. The filling height is 0.5-1.0 m above the highest water level line of the river channel, and the slope is treated by adopting a slope discharging mode of 1.

And step three, draining water and dredging in the weir. The construction method that the construction cofferdam is firstly constructed and then the open water is discharged is adopted. And (4) draining accumulated water in the cofferdam after the construction cofferdam is folded, and paying attention to control the precipitation speed so as to avoid the collapse of the side slope of the construction cofferdam. The river channel dredging is carried out by adopting a groove excavation mode, and dredging is carried out by adopting a 15kv slurry pump, a box type soil transport vehicle, a common double-bridge vehicle, a long-arm excavator and a common excavator. Firstly, sludge slurry at the position of a temporary construction pavement to be built on the inner side of a construction cofferdam is pumped to a box type soil transporting vehicle by a slurry pump, then a long-arm excavator is used for excavating the sludge at the construction pavement in a pit, and a common excavator is transported to the bottom of a river channel (when the river channel is wider, an excavator cannot excavate the sludge in the center of the river channel onto a river bank at one time). And (4) carrying out sequential construction of dredging of the river channel from the upstream to the downstream, and from the center to the two sides.

And step four, filling the access road in the weir. And after the river sludge is removed, backfilling the river sludge to the elevation of the pit bottom by adopting cohesive soil filler, and performing filling of a construction access in the pit in the construction cofferdam by adopting the combination of a loader and an excavator. The pavement structure layer of the construction pavement in the pit sequentially comprises geotextile, backfill cohesive soil, 30cm thick graded broken stone and 30cm C25 reinforced concrete from bottom to top.

And fifthly, inserting and driving the double-layer steel sheet piles. According to the measured driving site, the crawler crane and the vibratory hammer are adopted to drive the driving site to a proper depth in an inserting mode, and when the distance from the designed height to the designed height is smaller than 40cm, the inserting and driving speed is slowed down. The waterproof membrane is respectively paved on two sides of the construction cofferdam by adopting color strip cloth.

And step six, stacking the weir edge woven sand bags. And sand bag stacking is adopted within 2m from the edge of the cofferdam for temporary protection, and the stacking height is 1m.

Compared with the prior art, the utility model discloses a cross a river of buried tunnel full-section cofferdam pavement structure of pavement filling prior method. The main effects and advantages are as follows: (1) the stability is good, and the safety is high. A stable double-layer steel sheet pile system is formed by adopting a double-layer steel sheet pile cofferdam and fixing the double-layer steel sheet pile cofferdam through steel bar supports and split bolts. Meanwhile, cohesive soil is adopted for core filling, geotechnical cloth and a waterproof membrane are laid, the seepage-proofing effect is high, the seepage-proofing effect is good, the stability of a double-layer steel sheet pile system and the bearing capacity of the foundation of the construction cofferdam are improved, and the construction cofferdam has high safety. And (2) the construction speed is high, and the economic benefit is good. The double-layer steel sheet pile cofferdam adopts a sidewalk filling advance method, firstly utilizes the construction cofferdam to pump water and desilt in the cofferdam, and finally carries out double-layer steel sheet pile construction cofferdam construction, the inserting and the dismounting of the steel sheet piles are efficient, and the construction speed is high.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only illustrative of the principles of the present invention, and that various changes and modifications may be made without departing from the spirit and scope of the present invention, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (8)

1. A full-section cofferdam access road structure of a river-crossing underground tunnel is characterized by comprising a construction cofferdam (2) formed by enclosing channel steel, wherein at least one group of steel sheet piles arranged oppositely inside and outside are inserted and punched in the channel steel, and the steel sheet piles arranged oppositely inside and outside are connected through a horizontal connecting beam to form a stable double-layer steel sheet pile system; geotextile is laid at the bottom of the area of the construction cofferdam between the channel steels, a cohesive soil layer (6) is filled on the geotextile, and a waterproof membrane (5) is arranged on the cohesive soil layer (6); an in-pit construction sidewalk (10) is filled in the construction cofferdam (2), and woven sandbags (9) are piled at the side of the river-side weir of the construction cofferdam (2).

2. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, characterized in that the in-pit construction pavement (10) is composed of geotextile (4), a cohesive soil layer (6), a gravel layer and a reinforced concrete layer from bottom to top.

3. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, wherein the steel sheet piles oppositely arranged inside and outside are connected by split bolts.

4. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, wherein the filling height of the area between the channel steels of the construction cofferdam is 0.5-1.0 m above the highest water level of the river, and the slope is processed by slope releasing at a ratio of 1.

5. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, wherein the thickness of the waterproof membrane is 0.5mm.

6. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, wherein the pile height of the woven sandbags (9) is 1m, and the woven sandbags are used for temporary protection.

7. The full-section cofferdam pavement structure of a river-crossing underground tunnel according to claim 1, wherein a geotextile layer is arranged on the upper layer of the cohesive soil layer.

8. The full-section cofferdam pavement structure of the river-crossing underground tunnel according to any one of claims 1 to 7, wherein the bottom of the constructed cofferdam construction pavement is backfilled with cohesive soil filler.

Images