Bridge head bump bag type grouting repair construction method
Technical Field
The invention relates to the technical field of foundation repair, in particular to a bridge head bumping bag type grouting repair construction method.
Background
The phenomenon of vehicle bump at the bridge head is a phenomenon commonly existing in a road and bridge transition section in highway and railway engineering, and the main reason for generating the vehicle bump at the bridge head is caused by uneven settlement generated at two ends of a joint under the coupling action of multiple factors such as natural settlement of a road surface, vehicle load and the like due to the structural rigidity difference of a road and a bridge at the road and bridge transition section. The bump at the bridge head directly influences the speed, safety and comfort of driving, even causes the damage of personnel and vehicles. Meanwhile, the impact load generated by the jumping of the vehicle at the bridge head causes the irrecoverable damage of the bridge, and directly influences the service life and social benefit of the road.
The existing treatment method for bump at the bridge head has the following defects:
1) the method can effectively solve the problem of vehicle jumping, but the traffic is interrupted, the construction period is long, and the social and economic development is seriously restricted.
2) The method is mainly used for solving the problem of vehicle jump at the bridge head in the use stage of the road bridge by constructing a special device in the design and construction stage of the transition section of the road bridge, can be well used for treating the transition section of a newly-built bridge, but is not suitable for a large number of bridges in service in China and is not convenient for construction and reconstruction of the existing bridges.
3) The existing grouting treatment method cannot accurately control the grouting recovery area and recovery amount, even can generate transitional correction, and leads to partial pavement congestion, and the uncontrollable grouting method aggravates bridge head skip on the contrary.
Disclosure of Invention
The invention provides a bridge head bump bag type grouting repair construction method for solving the technical problems in the known technology, which can accurately control the lifting range and lifting amount of a road surface through grouting under the condition that the traffic of a road bridge transition section is not interrupted, and ensure the safety of a bridge structure and the driving safety.
The technical scheme adopted by the invention for solving the technical problems in the prior art is as follows: a construction method for bridge head bumping bag type grouting repair comprises the following steps: 1) designing a bag string, a structure horizontally distributed in a roadbed below a road surface of a vehicle bump area at the bridge head and the grouting amount of each bag string according to the field condition, wherein the bag string is provided with at least one bag, all the bags are connected in series by adopting a grouting pipe, the grouting pipe penetrates through the bags, and a plurality of uniformly distributed grouting holes are formed in the length direction of a pipe section of the grouting pipe positioned in the bags; 2) drilling a grouting hole and protecting the formed hole by adopting a wall protection cylinder, wherein the wall protection cylinder is formed by splicing at least two cylinder sheets; the expanded diameter of the bladder is greater than the outer diameter of the retaining cylinder; 3) connecting the bags into strings in a construction site, and arranging the bag strings in corresponding wall protection cylinders; 4) filling slow-setting type grout into the bag string according to the designed grouting sequence and grouting amount; 5) keeping a set time after grouting, monitoring the pavement settlement recovery condition in a bridge head bumping area, and if the pavement settlement recovery condition is recovered to a specified line shape, finishing the repair; if the road surface subsidence is not recovered to the specified line shape, the grouting is added again until the road surface subsidence is recovered to the specified line shape.
The step 1), a plurality of bag strings are arranged in rows and columns, the horizontal distance between the bag strings is 1-2.5m, the vertical distance between the bag strings on the uppermost layer is 2.5-4m, the vertical distance between the bag strings on the uppermost layer and a subsided road surface is 2.5-4m, the length of each bag string is 4-15m, the design strength is 1.0-2.5MPa, and the diameter of each bag string after grouting and expansion is 0.3-1.0 m; and 2), the inner diameter of the wall protection cylinder is 15-25cm, the thickness of the cylinder wall is 1-3cm, and the length is 4-15 m.
And repairing the two sides of the roadbed respectively.
The setting time of the delayed coagulation type slurry is 8-45 h.
The invention has the advantages and positive effects that: the bag string is installed in the drilling hole, so that the repair can be implemented under the condition that the traffic is not interrupted at the road and bridge transition section, accurate grouting can be realized, and the repair efficiency and the repair effect are improved. The assembled type wall protection cylinder penetrates through the drilled hole for protection, hole collapse can be avoided, the bag string is convenient to arrange, and during grouting, the high-pressure slurry expansion bag pulls the wall protection cylinder open, so that the grouting effect is not influenced; through the bag cluster that adopts a plurality of dispersions to arrange, can carry out local adjustment to the repair area through the slip casting volume in the control bag cluster, and then can carry out accurate restoration to whole repair area, improve the repair effect. In conclusion, the invention can accurately control the lifting range and lifting amount of the road surface by grouting under the condition that the traffic is not interrupted at the road and bridge transition section, thereby ensuring the safety of bridge structures and the driving safety.
Drawings
FIG. 1 is a schematic structural diagram of an application of the present invention;
FIG. 2 is a schematic diagram of a string of pockets in accordance with the present invention;
fig. 3 is a cross-sectional view of a retaining wall cylinder for use with the present invention.
In the figure: 1. the method comprises the following steps of (1) settling pavement in a bridgehead bump area, 2, a roadbed, 3, a retaining wall cylinder, 4, a bag string, 5, an abutment, 6, a bag, 7, a grouting pipe, 8, a grout outlet, 9, a grout stopping buckle, 10 and a cylinder piece.
Detailed Description
In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:
referring to fig. 1 to 3, a construction method for bridge head jumping vehicle bag type grouting repair includes the following steps:
1) the method comprises the steps of designing bag strings 4 and structures distributed in a roadbed 2 below a road surface 1 of a vehicle bump area at the bridge head in a horizontally dispersed mode and the grouting amount of each bag string 4 according to the field situation, specifically, reasonably designing the grouting hole position arrangement mode, the bag string length and the expansion diameter according to the actual width of the road, the roadbed height and the road surface settlement amount, calculating the grouting amount, arranging at least one bag 6 on each bag string 4, connecting all the bags 6 in series through a grouting pipe 7, enabling the grouting pipe 7 to penetrate through the bag 6, and arranging a plurality of uniformly distributed grouting holes 8 in the length direction on a pipe section, located inside the bag, of the grouting pipe 7. The roadbed 2 is arranged behind the abutment 5.
2) And drilling a grouting hole and protecting the formed hole by adopting the wall protection cylinder 3, specifically, transversely drilling the hole on the side surface of the roadbed by adopting a drilling machine, and dynamically protecting the wall protection cylinder 3 by adopting an assembled wall protection cylinder 3 in the drilling process, namely drilling and protecting the hole to prevent hole collapse. The wall protection cylinder 3 is formed by splicing at least two cylinder sheets 10; the expanded diameter of the bag 6 is larger than the outer diameter of the retaining wall cylinder 3, so that the retaining wall cylinder 3 is pulled open after the bag string is grouted and expanded, and then the roadbed soil is pushed, and the purpose of repairing the settled pavement is achieved.
3) The bag strings 6 are connected into strings in a construction site, the bag string 4 is arranged in the corresponding wall protection cylinder 3, specifically, the bag string is assembled in series on site according to design requirements, the bag string is arranged in a hole position protected by the wall protection cylinder, grouting equipment is installed, and preparation work before grouting is completed.
4) And (3) injecting delayed coagulation type slurry into the bag string 4 according to the designed grouting sequence and grouting amount, wherein the aim is to perform grouting again before the slurry is solidified according to the monitored pavement settlement recovery condition so as to achieve the optimal pavement settlement treatment effect.
5) Keeping a set time after grouting, monitoring the pavement settlement recovery condition in a bridge head bumping area, and if the pavement settlement recovery condition is recovered to a specified line shape, finishing the repair; if the road surface subsidence is not recovered to the specified line shape, the grouting is added again until the road surface subsidence is recovered to the specified line shape.
The arc-shaped cylinder pieces of the wall protection cylinder are connected through the joints and the slot structures, so that confining pressure can be borne, but expansion force from the inside of the wall protection cylinder cannot be borne. When the grouting bag expands, the protective wall cylinder naturally disperses under the action of the expansion force of the bag, so that the protective wall cylinder protects the grouting hole before grouting, hole collapse is avoided, the protective wall cylinder is pulled open by the bag expanded inside during grouting, and the grouting effect is not influenced.
In this embodiment, the bag strings 4 are arranged in two rows and four columns in the roadbed, the horizontal distance is 1.2m, the vertical distance is 2m, the vertical distance from the uppermost bag string 4 to the subsided road surface is 3m, the inner diameter of the assembled type retaining wall cylinder 3 is 15cm, the thickness of the cylinder wall is 2cm, and the length is 8 m. The wall protection cylinder is formed by splicing three arc-shaped cylinder pieces 10 with angles of 120 degrees, and adjacent cylinder pieces are connected by adopting joints and slots; the length of the bag string 4 is 8m, the bag 6 is made of water-retaining geotextile, the design strength is 1.0MPa, the diameter of the bag after grouting expansion is 0.5m, the bag 6 is tightly connected with the grouting pipe 7 by the grout stopping buckle 9, and a grout stopping rubber interlayer is arranged between the bag 6 and the grouting pipe 7 at the grout stopping buckle 9, so that the bag 6 and the grouting pipe 7 penetrating through the bag form sealing connection to prevent grout leakage. The grout injected into the bag string 4 is delayed coagulation type grout, the solidification time is 10 hours, the pavement settlement recovery condition is monitored after 2 hours and 4 hours after grouting, and if the recovery condition is good, grouting is finished; and if the expected recovery condition is not achieved, additionally grouting again.
The scheme is not limited, and test data show that when a repair structure is provided with a plurality of rows and columns of bag strings 4, the horizontal distance between the bag strings 4 is 1-2.5m, the vertical distance is 2-4m, the vertical distance between the uppermost bag string and a subsided road surface is 2.5-4m, the inner diameter of the assembled type wall protecting cylinder 3 is 15-25cm, the thickness of the cylinder wall is 1-3cm, and the length is 4-15 m; the length of the bag string 4 is 4-15m, the design strength is 1.0-2.5MPa, and the diameter of the bag after grouting expansion is 0.3-1.0 m; the setting time of the delayed coagulation type slurry is 8-45h, the pavement repairing effect is good, and the efficiency is high.
For the road surface with larger width or uneven bidirectional settlement, the two sides of the roadbed can be respectively provided with a repairing structure, and grouting repairing is respectively carried out from the two sides of the roadbed so as to achieve the effect of lifting the road surface as required.
Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and those skilled in the art can make many modifications without departing from the spirit and scope of the present invention as defined in the appended claims.