Underwater throwing-filling type isolation dam and implementation method thereof
Technical Field
The invention relates to an underwater throwing filling type isolation dam structure and an implementation method thereof. The method is suitable for projects which need to form independent reservoirs by dam construction and isolation at the periphery of established reservoirs, riverways and other water areas.
Background
With the continuous development of urbanization, some reservoirs originally built in the wilderness are gradually surrounded by cities and become water supply reservoirs for guaranteeing urban water, and in order to prevent rain and sewage in newly built peripheral cities from entering into a warehouse, an isolation project needs to be built in rivers where the sewage enters into the warehouse. In addition, the function of the built reservoir can be changed due to the change of the external environment after the built reservoir runs for a long time, for example, when a pumped storage power station and the like are built by using parts of the built reservoir, when conflicting running requirements occur, an isolation dam needs to be built to separate the functions of the reservoir. A reservoir is divided into a plurality of reservoirs capable of operating independently by building isolation dams in an established reservoir, and the problems of influence of new dam construction on the existing operation of the reservoir and difficult problems of construction guiding and intercepting are needed to be solved.
Disclosure of Invention
The technical problem to be solved by the invention is as follows: aiming at the existing problems, the underwater throwing filling type isolation dam and the implementation method thereof are provided to solve the problems of influence of new dam construction on the existing operation of the reservoir and difficult problems of construction guiding and closure.
The technical scheme adopted by the invention is as follows: the utility model provides an underwater throwing fills formula isolation dam which characterized in that: the isolation dam is located on the soil foundation, the isolation dam body is divided into an underwater filling dam body and a water rolling construction dam body, a vertical seepage-proofing structure arranged along the axis of the isolation dam body is arranged in the dam body, and the vertical seepage-proofing structure comprises curtain grouting arranged in a rock foundation below the soil foundation, seepage-proofing walls arranged in the soil foundation and the underwater filling dam body and a cast-in-place concrete core wall arranged in the water rolling construction dam body.
The underwater cast-fill dam body sequentially comprises a collapse area, a stone slag cast-fill area, a fine stone material mixed-cast area, an impervious wall, a fine stone material mixed-cast area, a stone slag cast-fill area and a collapse area from upstream to downstream.
The fine stone mixed polishing area adopts a clay material and a stone slag material with the maximum particle size of 20cm and the soil-stone ratio of 2: 3-1: 1; and the stone slag throwing filling area and the collapse area adopt stone slag materials with the maximum particle size not larger than 80 cm.
The rock slag material requires that the saturated uniaxial compressive strength is not less than 30MPa, the rock is weakly weathered to be fresh, and the grain composition is good.
The overwater rolling construction dam body sequentially comprises a rockfill filling area, a transition material area, a cast-in-place concrete core wall, a transition material area and a rockfill filling area from the upstream to the downstream.
The cast-in-place concrete core wall extends to the position above the dam crest of the dam body to form the wave wall.
A bank side flood discharge gate communicated with the upstream and the downstream of the isolation dam is arranged on a bank side at one end of the isolation dam, the bank side flood discharge gate is provided with a water inlet channel, a control section and a water outlet channel from the upstream to the downstream in sequence, and the control section comprises a lower gate chamber and an upper opening and closing machine room;
the curtain grouting extends to the lower part of the lower lock chamber, and the impervious wall and the cast-in-place concrete core wall extend to the lower lock chamber and are connected with the side wall of the lower lock chamber through a water stopping structure.
And the side wall surface of the lower gate chamber close to one side of the dam body of the isolation dam is a vertical surface.
The water stopping structure is provided with a seepage-proof wall expanded end, and the seepage-proof wall expanded end is tightly attached to the lower lock chamber side wall and is connected with the seepage-proof wall and the cast-in-place concrete core wall into a whole; a plurality of perforation holes are drilled from top to bottom corresponding to the gap between the expansion end of the impervious wall and the lower lock chamber, and water-soluble polyurethane is poured into the perforation holes.
The implementation method of the underwater throwing filling type isolation dam is characterized by comprising the following steps:
building a temporary cofferdam I close to the bank so as to form a dry land construction environment of a bank flood gate on the bank;
excavating a flood discharge gate foundation, and constructing a bank side flood discharge gate communicated with the upper and lower streams of the isolation dam according to the structural requirements;
a semicircular steel pipe protective cover is arranged on the side wall of the lower lock chamber in the bank flood discharge gate close to the isolation dam by taking the center line of a seepage-proof wall as a control line, and is fixed on the side wall of the lower lock chamber by temporary fixing measures, and the diameter of the steel pipe protective cover is slightly larger than the thickness of the seepage-proof wall;
backfilling the stone slag to the top elevation of the underwater cast-fill dam body in a layered manner in a foundation pit at one side of the lower gate chamber close to the isolation dam, fixing the steel pipe protective cover through the stone slag, and removing a temporary fixing measure along with the rising of the stone slag backfilling from bottom to top;
after the upstream and the downstream of the control section are plugged by a temporary cofferdam II in the flow passage of the bank flood discharge gate, the temporary cofferdam I is removed;
underwater filling is carried out from two banks to the middle part or from one bank to the opposite bank by adopting an encroachment method according to the design size of the dam body partition and the material requirements of each partition, so as to form an underwater filling dam body;
after the construction of the underwater cast-fill dam body is completed, a dynamic compaction method is adopted to carry out dynamic compaction reinforcement on a ballast cast-fill area and a fine stone mixed cast area of the underwater cast-fill dam body;
constructing a slotted hole of the impervious wall and pouring the impervious wall; after the outer side groove hole of the semicircular steel pipe protective cover is formed, replacing accumulated water of the semicircular steel pipe protective cover with wall fixing slurry constructed by the impervious wall, lifting the semicircular steel pipe protective cover by using lifting equipment, and protecting the stability of the groove wall of the expanded end of the impervious wall by the wall fixing slurry in the protective cover so as to ensure that the groove hole of the impervious wall extends to the side wall of the lower lock chamber;
after the impervious wall is formed, performing dam foundation curtain grouting construction from the top of the impervious wall;
performing water rolling construction on a dam body, removing a diaphragm wall construction platform at the top of a diaphragm wall after diaphragm wall construction is finished, chiseling out the mud-containing concrete at the top of the diaphragm wall, binding a reinforcing mesh sheet of an upper cast-in-place concrete core wall, overlapping the reinforcing mesh sheet with the diaphragm wall, and erecting a mold to pour the cast-in-place concrete core wall;
pouring a concrete core wall in situ, performing dam body rolling and filling construction on two sides to a dam crest elevation, drilling a plurality of crack holes downwards from the dam crest corresponding to a gap between the expanded end of the impervious wall and the lower gate chamber, and filling water-soluble polyurethane into the crack holes to form water stop plugs to form an 8-shaped water stop structure;
continuously pouring the wave wall part on the upper part of the cast-in-place concrete core wall;
performing foundation consolidation grouting and curtain grouting construction on the bottom plate of the lower lock chamber;
demolition after the lower lock chamber has water-retaining conditions
And (5) removing the temporary cofferdam II after the construction of the lower lock chamber is finished.
The invention has the beneficial effects that: the invention builds a new reservoir on the existing water area through the underwater throwing filling type isolation dam, has the advantages of simple construction flow guide and low investment, realizes the function division of the original reservoir under the condition of not influencing the operation of the existing reservoir, and further increases the service range, the service capacity or the service quality of the reservoir and the like.
The invention utilizes the underwater throwing and filling technology and the dynamic compaction treatment process to ensure that the underwater throwing and filling dam body meets the performance requirement of permanent operation; the efficient dam body seepage-proofing effect is provided through a vertical seepage-proofing structure formed by various combinations of the seepage-proofing wall, the cast-in-place concrete core wall and curtain grouting; the lateral seepage-proofing connection of the seepage-proofing wall, the cast-in-place concrete core wall and the lower lock chamber concrete structure is realized through the drilling water-stopping structure.
The invention utilizes the bank flood discharge gate to realize coordination and coordination of functions of the reservoir under special working conditions and flood control safety of the newly built reservoir.
Drawings
Fig. 1 is a floor plan of an embodiment.
FIG. 2 is a typical cross-sectional view of the dam body of the underwater throwing filling type isolation dam in the embodiment.
Fig. 3 is a transverse cross-sectional view of the embodiment.
FIG. 4 is a schematic view showing the connection between the diaphragm wall and the lower lock chamber in the embodiment.
In the figure: 1. shoreside; 2. a reservoir area; 3-1, a stone slag throwing and filling area; 3-2, a fine stone mixed polishing area; 3-3, collapse zone; 3-4, a rockfill filling area; 3-5, a transition material area; 3-6, curtain grouting; 3-7, impervious walls; 3-8, casting a concrete core wall in situ; 4. a control section; 4-1, a lock chamber; 4-2, superstructure; 5. a water inlet channel; 6. a water outlet channel; 7-1, a temporary cofferdam I; 7-2, a temporary cofferdam II; 8. a rock foundation; 9. a soil foundation; 10. a water stopping structure; 10-1, a semicircular steel pipe protective cover; 10-2, perforation; 10-3, a water stop plug; 12. backfilling concrete in the foundation pit; 13. a rockfill body; 14. a slot hole.
Detailed Description
The embodiment has an underwater jettisoning type isolation dam arranged on a reservoir area and used for water retaining and isolating, and a shoreside flood discharge gate arranged on the shoreside and communicated with the upstream and the downstream of the underwater jettisoning type isolation dam.
In the embodiment, the underwater throwing filling type isolation dam is located on a soil foundation and is divided into an underwater throwing filling dam body and an overwater rolling construction dam body according to the water level condition during construction. The underwater throwing filling type isolation dam is internally provided with a vertical seepage-proofing structure arranged along the axis of the underwater throwing filling type isolation dam, the vertical seepage-proofing structure comprises curtain grouting arranged in a rock foundation below an earthen foundation, seepage-proofing walls arranged in the earthen foundation and the underwater throwing filling dam and a cast-in-place concrete core wall arranged in an overwater rolling construction dam, and the seepage-proofing walls are arranged on one side of a higher water level (upstream) in the middle of the underwater throwing filling type isolation dam.
In the embodiment, the underwater dumping dam body is designed according to the underwater stable body type and the diaphragm wall construction requirement and by considering the slope collapse possibly existing in the operation period. The underwater cast-fill dam body sequentially comprises a collapse area, a stone slag cast-fill area, a fine stone material mixed-cast area, an impervious wall, a fine stone material mixed-cast area, a stone slag cast-fill area and a collapse area from upstream to downstream. The fine stone mixed-throwing area adopts clay materials and stone slag materials with the maximum particle size of 20cm and the soil-stone ratio of 2: 3-1: 1. And the ballast throwing filling area 3-1 and the upstream and downstream collapse areas 3-3 adopt ballast materials with the maximum particle size of not more than 80 cm. The rock slag material of the casting filler requires that the saturated uniaxial compressive strength is not less than 30MPa, the rock is weakly weathered to be fresh, and the grain composition is good.
The dam body for the water upper rolling construction in the embodiment is designed according to the layered rolling construction process, transition material areas are arranged on two sides of the cast-in-place concrete core wall, and rockfill filling areas are arranged outside the transition material areas. The cast-in-place concrete core wall extends to the position above the dam crest to form the wave wall.
In this embodiment, the bank side flood discharge gate is provided with an inlet channel, a control section and an outlet channel in sequence from upstream to downstream, and the control section comprises a lower gate chamber and an upper opening and closing machine room located above the lower gate chamber. The control section is located on a bank rock foundation, anti-seepage treatment is carried out in the rock foundation by curtain grouting, and the curtain grouting is connected with the curtain grouting below the underwater throwing filling type isolation dam. In the embodiment, the side wall surface of the lower lock chamber close to one side of the dam body is a vertical surface and is connected with the impervious wall and the cast-in-place concrete core wall in the dam body through the water stop structure.
The water stopping structure of the embodiment is provided with an anti-seepage wall expanded end, and the anti-seepage wall expanded end is tightly attached to the side wall of the lower lock chamber and is connected with the anti-seepage wall and the cast-in-place concrete core wall into a whole; 2 perforation holes with the diameter of 200mm are formed from top to bottom corresponding to the gap between the expanded end of the impervious wall and the lower lock chamber, and water-soluble polyurethane is poured into the perforation holes to form a water stop plug, so that an 8-shaped water stop structure is formed.
The specific construction method of the embodiment is as follows:
under the condition that the normal operation of the reservoir is not influenced, the reservoir water level is properly reduced, and a temporary cofferdam I is built close to the bank according to the relation between the water level and the excavation foundation of the bank side flood discharge gate, so that a dry land construction environment of the bank side flood discharge gate is formed on the bank;
excavating a foundation of the flood discharge gate, constructing the flood discharge gate according to the structural requirements, wherein the flood discharge gate comprises a water inlet channel, a control section and a water outlet channel, and concrete is backfilled in a foundation pit at one side of a lower gate chamber in the control section of the flood discharge gate, which is close to a reservoir bank;
on the wall of the lower gate chamber close to the dam body side in the flood discharge gate control section, a semi-circular steel pipe protective cover is mounted in close contact with the side wall of the lower gate chamber by taking a seepage-proof wall central line as a control line, the center of the semi-circular steel pipe protective cover is positioned on the seepage-proof wall central line, and temporary fixation is carried out by adopting measures such as bolts and the like; the diameter of the steel pipe protective cover is slightly larger than the wall thickness of the impervious wall;
the method comprises the following steps that backfill rock ballast is rolled and backfilled in a foundation pit on one side, close to a dam body, of a lower gate chamber in a layered mode to the top elevation of the dam body poured and filled underwater, a semicircular steel pipe protective cover on the side wall of the lower gate chamber is fixed through the rock ballast, and temporary fixing measures are continuously removed along with the rising of a rock ballast filling layer from bottom to top;
after the upstream and downstream of the control section are plugged by a temporary cofferdam II in the flow passage of the flood discharge gate, the temporary cofferdam I is removed;
underwater throwing and filling are carried out from two banks to the middle part or from one bank to the opposite bank by adopting an encroachment method according to the designed size of the dam body partition and the material requirements of each partition, wherein the underwater throwing and filling comprises a collapse area, a rock ballast throwing and filling area and a fine rock mixed throwing area close to a core wall;
after the underwater partial filling construction is completed, a stone ballast throwing and filling area and a fine stone mixed and throwing area are subjected to dynamic compaction reinforcement by adopting a dynamic compaction method;
constructing a slotted hole of the impervious wall and pouring the impervious wall; the construction boundary of the slotted hole close to one side of the lower lock chamber is away from the semicircular steel pipe protection cover by a certain safety distance, so that mutual damage caused by mutual collision of drilling equipment and the semicircular steel pipe protection cover is avoided; after the outer side slot hole of the semicircular steel pipe protective cover is formed, the accumulated water of the semicircular steel pipe protective cover is replaced by wall fixing slurry constructed by the impervious wall, the semicircular steel pipe protective cover is lifted by a lifting device, and the wall fixing slurry in the protective cover protects the stability of the slot wall of the expanded end of the impervious wall, so that the slot hole of the impervious wall extends to the side wall of the lower lock chamber;
after the impervious wall is formed, performing dam foundation curtain grouting construction from the top of the impervious wall;
performing dam body construction of water rolling construction; after the construction of the impervious wall is finished, removing a top impervious wall construction platform, chiseling out the concrete containing the mud at the top of the impervious wall, binding a reinforcing mesh sheet of the upper cast-in-place concrete core wall, overlapping the reinforcing mesh sheet with the impervious wall, erecting a mould along with a rockfill filling area and a transition material area which are rolled and filled at the upper part, and pouring the cast-in-place concrete core wall, and ascending layer by layer;
after the dam body for the over-water rolling construction and the cast-in-place concrete core wall are constructed to the dam crest elevation, 2 crack-bridging holes with the diameter of 200mm are drilled from the dam crest corresponding to the gap between the expanded end of the impervious wall and the lower gate chamber, water-soluble polyurethane is poured into the holes to form water stop plugs, an 8-shaped water stop structure is combined, and hole sealing treatment is carried out on the top;
continuously pouring the wave wall part on the upper part of the cast-in-place concrete core wall;
performing foundation consolidation grouting and curtain grouting construction on the bottom plate of the lower lock chamber;
constructing an internal structure of the lower lock chamber and a traffic bridge, a working bridge, a gate slot, a gate, a hoist, a bent or an upper machine room and the like on the upper part, and dismantling a temporary cofferdam II on the upper and lower streams of the lock chamber;
construction of pavement structures and revetments, etc.