CN211395715U - Dewatering and dewatering structure for horizontal sand well of annular foundation pit - Google Patents

Abstract

The utility model relates to a ring foundation ditch horizontal sand well precipitation unwatering structure, encircle the vertical sand well that foundation ditch interval set up and at least one horizontal sand well that encircles the foundation ditch setting including a plurality of, horizontal sand well is arranged in the aquifer at foundation ditch place, and horizontal sand well links to each other with vertical sand well, and horizontal sand well still is connected with the vertical tube well of a plurality of, a plurality of vertical tube well sets up around the foundation ditch interval, and vertical tube well includes water filtering section and water storage section, and the boundary line of water filtering section and water storage section is located the bottom boundary face of the horizontal sand well of below or is less than the bottom boundary face of the horizontal sand well of below, be provided with pumping equipment in the water storage section. The utility model discloses when reaching foundation ditch dewatering and dredged the purpose, the position of the horizontal sand well structure end interface of adoption is very shallow, and it is far less than perpendicular well point degree of depth to avoid extracting more irrelevant groundwater, make because of extracting more groundwater, extracting a series of problems that deep groundwater causes more and alleviate, obtain better solution even.

Description

Dewatering and dewatering structure for horizontal sand well of annular foundation pit

Technical Field

The utility model relates to a construction field, concretely relates to ring foundation ditch horizontal sand well dewatering and drainage structure.

Background

The foundation pit dewatering mainly adopts a vertical well point pumping method surrounding the foundation pit surrounding edge to reduce the water level of the foundation pit, however, the depth of the well point is often very large due to the depth of a funnel of the vertical well point dewatering, for example, the depth of the foundation pit dewatering well point in a certain area is usually set to be 20-25 m. At such deep well sites, the aquifers traversed tend to be multi-layered, while the lower aquifers have negligible impact on the pit, but still require pumping of their groundwater. In many areas, the phenomenon that a shallow aquifer is rich in water and weak, and deep aquifers are rich in water is common. The method in the industry at present for dewatering the foundation pit has the following problems: the well point depth is large, and the pumping cost is high; underground water which is not required to be pumped is pumped, and underground water resources are wasted, so that lower water resources are easily polluted; causing excessive settlement of the ground, especially uneven settlement, and causing serious adverse effects on the surrounding environment of the engineering.

For example, utility model patent with publication number CN201110224948 discloses a well point location water pumping pipe well and well point location water pumping method, through adopting the downcomer well that no sand pipe well section, standpipe well section are constituteed, the water source in the aquifer in the foundation ditch precipitation depth range has been gathered effectively, utilize pumping equipment water level extraction standpipe well section to store the water source, can solve not draw water, draw water and not pollute "dredge not dry" difficult problem under the "dredge not dry" condition when independent aquifer in underground water source and the aquifer groundwater is not abundant below the foundation ditch precipitation depth. However, the underground water drainage method still belongs to the range of a vertical well point dewatering structure, the effective water collection surface is small, the drainage and pumping time is long, the pumped underground water is still too much, and the difficult problem of 'drainage and drainage' cannot be solved when the underground water of the aquifer under the 'drainage and drainage' condition is rich because the underground water has no function of cutting off the hydraulic connection inside and outside the foundation pit.

Disclosure of Invention

The utility model discloses an overcome and adopt perpendicular well point water pumping method to carry out foundation ditch precipitation among the prior art and the total precipitation that produces is big, precipitation infiltration line is steep, easily has the problem of drenching not dry, piping, the inhomogeneous settlement in ground, provides a ring foundation ditch horizontal sand well precipitation structure of drenching.

In order to realize the purpose, the technical scheme of the utility model is that:

the utility model provides a horizontal sand well dewatering structure of ring foundation ditch, includes that a plurality of encircles the vertical sand well that foundation ditch interval set up and at least one encircles the horizontal sand well that the foundation ditch set up, horizontal sand well is arranged in the aquifer at foundation ditch place, and horizontal sand well links to each other with vertical sand well, and horizontal sand well still is connected with the vertical tube well of a plurality of, a plurality of vertical tube well sets up around the foundation ditch interval, and vertical tube well includes water filtering section and water storage section, water filtering section and water storage section set gradually from top to bottom, and the boundary line of water filtering section and water storage section is located on the bottom boundary face of the horizontal sand well of below or is less than the bottom boundary face of the horizontal sand well of below, be provided with pumping equipment in the water storage section.

Furthermore, horizontal sand well includes that a plurality of end to end links to each other in proper order the columniform sand column and the dado circle that is located the sand column top, and is adjacent there is partial intersection between the sand column, and sand column and vertical sand well set up with one heart.

Furthermore, the number of the horizontal sand wells in the lower aquifer where the foundation pit is located is one, and a precipitation infiltration line formed by the horizontal sand wells is 0.5m lower than the bottom of the foundation pit.

And further, the horizontal sand wells of the lower aquifer where the foundation pit is located are all located in the lower aquifer.

Furthermore, the horizontal sand well part in the lower aquifer where the foundation pit is located in the lower aquifer, and the bottom interface of the horizontal sand well is lower than the bottom interface of the lower aquifer and is located in the water-resisting layer below the lower aquifer.

Furthermore, one or more horizontal sand wells are arranged in one or more aquifers above the lower aquifer where the foundation pit is located, the bottom interface of the horizontal sand well in the non-lower aquifer is located in the water-resisting layer below the aquifer where the foundation pit is located, and the plurality of horizontal sand wells in the aquifer where the foundation pit is located correspond to each other.

Furthermore, horizontal sand well is the cylindric structure that is filled by high water permeability material and forms, vertical sand well is two segmentation structures, and the hypomere of vertical sand well is the columnar structure that is filled by high water permeability material and forms, and the upper segment of vertical sand well is located the above-mentioned aquifer water level line, and the upper segment of vertical sand well is the columnar structure that is filled by impervious water material and forms.

Through the technical scheme, the beneficial effects of the utility model are that:

the utility model discloses the horizontal sand well that is arranged in the aquifer is filled by high permeability material and forms, the permeability of the horizontal sand well structure of the ring foundation ditch of formation is greater than the permeability of the aquifer around it, water in the aquifer is to vertical sand well, permeate in the horizontal sand well, and flow to in the vertical tube well, so when drawing water in a large amount in vertical tube well, water level descends in the vertical tube well, and then the rivers that cause in the horizontal sand well structure of high permeability flow into vertical tube well, water level in the horizontal sand well structure reduces fast, thereby make the water pressure reduction in the horizontal sand well structure, horizontal sand well water pressure reduction arouses again that groundwater around the horizontal sand well flows to horizontal sand well in.

The horizontal sand well in the horizontal sand well dewatering and drying structure can be regarded as a continuous sand wall of a ring of foundation pit, when the bottom interface of the horizontal sand well is arranged in a water-resisting layer below the aquifer, the horizontal sand well dewatering and drying structure has the function of cutting off the hydraulic connection inside and outside the foundation pit, so that the inside and outside of the foundation pit are referred to, the part surrounded by the horizontal sand well dewatering and drying structure is the inside, and the outside is the outside, and the hydraulic connection inside and outside the foundation pit is cut off, so that the difficult problem of 'non-dewatering' can be thoroughly solved. The vertical sand well in the horizontal sand well structure can lead the underground water in the aquifer where the vertical sand well is located into the horizontal sand well without any limiting condition, plays the role of a water seepage well and can drain the underground water of the aquifer through which the vertical sand well passes. Therefore, the utility model discloses a design of horizontal sand well dewatering structure for its each part fully cooperates, cooperates closely, can realize the purpose of foundation ditch dewatering well.

When the water amount of one or more layers of aquifers on the lower aquifer of the foundation pit engineering is rich, and the single horizontal sand well dewatering structure cannot dewater the aquifer and can seriously affect the foundation pit engineering construction, one or more layers of horizontal sand well structures can be additionally arranged at the bottom interface of one or more layers of aquifers, and the bottom interface of the additionally arranged horizontal sand well structure is positioned in a water barrier below the aquifer, so that the purpose of quickly dewatering and dewatering the foundation pit is realized. For the situation of the multilayer water-rich aquifer of the foundation pit engineering, the dewatering effect of the widely used vertical well point dewatering method is unsatisfactory, and even if the effect is improved by greatly reducing the well point distance, the defect of the vertical well point dewatering still exists, and the problem of 'dewatering without dryness' is still difficult to avoid.

The horizontal sand well structure around the foundation pit makes the infiltration line of underground water in the foundation pit slower than that when a single water channel is arranged, so that when the aim of dewatering the foundation pit is fulfilled, the position of the bottom interface of the adopted horizontal sand well structure is also shallow and far smaller than the depth of a vertical well point, thereby avoiding extracting more irrelevant underground water, relieving a series of problems caused by extracting more underground water and extracting more deep underground water, and even better solving the problems.

Drawings

Fig. 1 is one of the top view structural schematic diagrams of the vertical sand well, the vertical pipe well, the horizontal sand well and the foundation pit of the utility model;

FIG. 2 is a schematic structural diagram according to a first embodiment;

fig. 3 is a second schematic view of the top-view structure of the vertical sand well, the vertical pipe well, the horizontal sand well and the foundation pit of the present invention;

FIG. 4 is a schematic view of the cross-sectional structure A-A of FIG. 3 according to the present invention;

fig. 5 is a schematic view of the cross-sectional structure B-B of fig. 3 according to the present invention;

fig. 6 is a second schematic sectional view of the cross-section a-a of fig. 3 according to the present invention;

FIG. 7 is one of the schematic structural views of the underwater soil body agitator of the present invention;

fig. 8 is a second schematic structural view of the underwater soil body agitator of the present invention;

fig. 9 is a third schematic structural view of the underwater soil body agitator of the present invention;

fig. 10 is a fourth schematic structural view of the underwater soil body spreading and stirring device of the present invention;

FIG. 11 is a longitudinal cross-sectional view of the underwater soil body agitator of the present invention;

FIG. 12 is a transverse cross-sectional view of the underwater soil body agitator of the present invention;

fig. 13 is a cross-sectional view of the cutting agitator of the present invention;

FIG. 14 is one of the construction process diagrams of the underwater soil body agitator of the present invention;

fig. 15 is a second construction process diagram of the underwater soil body stirring device of the present invention;

FIG. 16 is a third drawing of the construction process of the underwater soil body agitator of the present invention;

FIG. 17 is a fourth drawing of the construction process of the underwater soil body agitator of the present invention;

fig. 18 is a third schematic view of the cross-sectional structure a-a of fig. 3 according to the fourth embodiment of the present invention;

fig. 19 is a fourth schematic view of the cross-sectional structure a-a of fig. 3 according to the fifth embodiment of the present invention;

fig. 20 is a fifth schematic view of the sectional structure a-a of fig. 3 according to the sixth embodiment of the present invention.

The reference numbers in the drawings are as follows: 20 is a vertical sand well, 30 is a vertical pipe well, 40 is a foundation pit, 50 is a wetting line, 60 is a retaining ring, 70 is a horizontal sand well, and 80 is a sand column;

101 is a first water-resisting layer, 100 is a first aquifer, 201 is a second water-resisting layer, 200 is a second aquifer, 301 is a third water-resisting layer, 300 is a third aquifer, 401 is a fourth water-resisting layer;

the cutting tool comprises an outer pipe 1, an inner pipe 2, a cutting stirring frame 3, an upper cutting plate 301, a lower cutting plate 302, a drill bit 4, a partition plate 5, a connecting core pipe 6, an upper slurry outlet 7, a lower slurry outlet 8, an inverted T-shaped hole 9, a side through hole 10, a low-pass pipe 11, an upper through pipe 12, a lower through pipe 13 and a positioning hoop 14.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

For convenience of description, the underground aquifers are referred to as a first aquifer 100, a second aquifer 200, a third aquifer 300, and the like in this order from top to bottom, and the water barriers between the ground and the first aquifer 100 and between the aquifers are referred to as a first water barrier 101, a second water barrier 201, a third water barrier 301, a fourth water barrier 401, and the like in this order.

Example one

As shown in fig. 1, a ring foundation pit horizontal sand well dewatering and draining structure includes a plurality of vertical sand wells 20 arranged around foundation pit 40 at intervals and at least one horizontal sand well 70 arranged around foundation pit 40, the horizontal sand well 70 is located in the aquifer where foundation pit 40 is located, the horizontal sand well 70 is connected with the vertical sand well 20, the horizontal sand well 70 is further connected with a plurality of vertical pipe wells 30, a plurality of the vertical pipe wells 30 are arranged around foundation pit 40 at intervals, the vertical pipe well 30 includes a water filtering section and a water storage section, the water filtering section and the water storage section are sequentially arranged from top to bottom, the boundary of the water filtering section and the water storage section is located on the bottom interface of the lowest horizontal sand well 70 or is lower than the bottom interface of the lowest horizontal sand well 70, and a water pumping device is arranged in the water storage section.

In this embodiment, the number of the horizontal sand wells 70 disposed around the foundation pit 40 is one, and as a preferred embodiment, as shown in fig. 2, the horizontal sand wells 70 are located in a lower aquifer where the foundation pit 40 is located, and the lower aquifer is the deepest aquifer that has a detrimental effect on the foundation pit construction.

The horizontal sand wells 70 and the vertical sand wells 20 may be filled with a highly permeable material having a permeability greater than the permeability of the aquifer surrounding them. The horizontal sand well 70 is arranged around the foundation pit 40, a sand wall for draining the foundation pit 40 is formed in a lower aquifer where the horizontal sand well 70 is located, the vertical sand well 20 is communicated with the upper aquifer and the lower aquifer, water in each aquifer where the vertical sand well 20 is located enters the horizontal sand well 70 through the vertical sand well 20, when a large amount of water is pumped in the vertical pipe well 30, the water level in the vertical pipe well 30 is lowered, water in the high-permeability horizontal sand well 70 flows into the vertical pipe well 30, the water level in the structure of the horizontal sand well 70 is rapidly lowered, so that the water pressure in the structure of the horizontal sand well 70 is lowered, the water pressure in the horizontal sand well 70 is lowered, groundwater around the horizontal sand well 70 and the vertical sand well 20 and the water in the vertical sand well 20 flow into the horizontal sand well 70, rapid water drainage is achieved, and the drainage amount is large.

The dynamics theory of underground water shows that the water channel catchments water quickly, the infiltration lines in the aquifers at two sides are slow, and the water surface of the water channel and the underground water surfaces at two sides have the same butterfly shape and are gentler than the infiltration line of the landing funnel shape of the vertical well point. The underground water in the foundation pit is influenced by the drainage of the annular horizontal sand well formed around, and the infiltration line is slower than that of a single water channel. That is, the bottom interface of the horizontal sand well 70 can be shallow and far less than the depth of the vertical well point, so that more irrelevant groundwater is prevented from being pumped, a series of problems caused by more pumping of groundwater and more pumping of deep groundwater are relieved, and even better solved.

As a preferred embodiment, the cross section of the horizontal sand well 70 is rectangular, as shown in fig. 2, which further increases the water inflow per unit area, and realizes a large displacement and quick drainage.

Example two

Based on the first embodiment, because the horizontal sand well 70 with a rectangular cross section has a high difficulty and a high cost in actual construction, in this embodiment, as shown in fig. 3 to 5, the horizontal sand well 70 includes a plurality of cylindrical sand columns 80 connected end to end in sequence and a retaining wall ring 60 located above the sand columns 80, a partial intersection exists between adjacent sand columns 80, and the sand columns 80 and the vertical sand well 20 are concentrically arranged. Specifically, horizontal sand well 70 is for filling the cylindric structure that forms by high water permeability material, vertical sand well 20 is two segmentation structures, and the column structure that forms is filled for by high water permeability material to the hypomere of vertical sand well 20, and the upper segment of vertical sand well 20 is located more than the superiors' aquifer water level line, and the column structure that forms is filled for by water impermeability material to the upper segment of vertical sand well 20, and is more specific, and high water permeability material can adopt the gravel sand material, and water impermeability material can adopt the clay. In this embodiment, the sand column 80 is concentric with the vertical sand well 20, when a straight hole is drilled in the vertical sand well 20 to be close to the horizontal sand well 70, an underwater soil mass stirrer is used to stir and harden the soil mass at the top of the horizontal sand well 70, a retaining wall ring 60 is formed, the formed retaining wall ring 60 is umbrella-shaped, and then the soil mass at the sand column is taken out under the actions of the retaining wall ring 60, the top and the mud retaining wall, so that the sand column 80 is formed, and the retaining wall ring 60 is supported by the sand soil on the outer wall of the lower hole-expanding space to prevent falling and collapsing, so that the diameter of the lower part of the retaining wall ring 60 is larger than that of the sand column 80, and the top of the sand column 80 is prevented from collapsing due to the scattering of the sand soil on the outer wall of the hole-expanding space during hole expanding. The intersections between the adjacent sand columns 80 are formed to communicate with the enlarged hole portions to form a water flow path in the horizontal sand well 70 communicating with each other similarly to the first embodiment, and further, the cross-section of the intersecting portions is still rectangular due to the intersections between the adjacent sand columns 80.

EXAMPLE III

On the basis of the above embodiment, as shown in fig. 3 to 5, a dewatering and dewatering method for a dewatering and dewatering structure of a horizontal sand well of an annular foundation pit includes the following steps:

step A, according to the construction position of the foundation pit engineering, determining a water-bearing layer system, determining the thickness and the depth of each water-bearing layer, and the position of the lower water-bearing layer, and judging the water content of each water-bearing layer, wherein in the embodiment, two water-bearing layers, namely a first water-bearing layer 100 and a second water-bearing layer 200, are arranged in the construction range of the foundation pit, and according to the condition that the deepest water-bearing layer which has a hazardous influence on the foundation pit construction is the lower water-bearing layer, the second water-bearing layer 200 is judged to be the lower water-bearing layer;

b, calculating the position and the size of the horizontal sand well 70 in the lower aquifer under the condition that the precipitation infiltration line in the foundation pit is positioned below 0.5m of the bottom of the foundation pit according to a theoretical formula of the dynamics of the groundwater in the ditch; if the bottom interface of the horizontal sand well 70 is calculated to be higher than the bottom interface of the lower aquifer and the aquifer is not easy to form a 'dry-out' condition, a schematic diagram as shown in fig. 4 is formed, and the horizontal sand well 70 of the lower aquifer where the foundation pit 40 is located in the lower aquifer completely, that is, the horizontal sand well 70 is located in the second aquifer 200 completely; if it is calculated that the bottom interface of the horizontal sand well 70 is located at or near the bottom interface position of the lower aquifer, the aquifer in this state is likely to become an "unwatered" aquifer, and to avoid such an "unwatered" condition, the bottom interface of the horizontal sand well 70 should be moved down to a water barrier below the aquifer, as shown in fig. 6, where the horizontal sand well 70 located in the lower aquifer where the foundation pit 40 is located is partially located in the lower aquifer, and the bottom interface of the horizontal sand well 70 is lower than the bottom interface of the lower aquifer and is located in the water barrier below the lower aquifer, that is, the horizontal sand well 70 is partially located in the second aquifer 200 and partially located in the third water barrier 301;

step C, determining the diameter of the vertical sand well 20, the position, the size and the interval of the sand columns 80 according to the position and the size of the horizontal sand well 70 in the step B, and constructing vertical straight holes around the foundation pit 40 by taking the diameter of the vertical sand well 20 and the interval of the sand columns 80 as construction data to form a hole pattern of the vertical sand well 20;

d, determining the hole expanding size of the bottom of the vertical straight hole according to the position and size of the sand column 80, adopting an underwater soil body expanding stirrer to expand and stir and harden the bottom of the vertical straight hole in the step C, manufacturing a wall protection ring 60 at the top of the sand column 80, forming the wall protection ring 60 into an umbrella shape, and taking out the soil body at the sand column 80 under the action of the top protection of the wall protection ring 60 and the slurry side protection wall, so that the bottom expanding space, namely the space of the sand column 80 is formed, because the wall protection ring 60 is supported by the sand soil on the outer walls around the hole expanding space at the lower part of the wall protection ring to prevent falling and collapsing, the diameter of the lower part of the wall protection ring 60 is larger than that of the sand column 80, and simultaneously, the scattering of the sand soil on the outer walls of the hole expanding space and collapsing of the top of the hole expanding space can;

e, filling high-permeability materials, such as gravel sand, in the reamed holes and the vertical straight holes formed in the step D to form the sand columns 80 and the vertical sand wells 20, and filling the vertical sand wells 20 above the water level line of the aquifer at the uppermost layer with water-resisting materials, such as clay, so as to prevent the ground from being filled underwater;

step F, calculating the water inflow of the foundation pit, determining the number, the position and the size of the vertical tube wells 30, drilling holes, filling a water-resisting material such as clay on the periphery of the water storage section, filling a material with high water permeability such as gravel sand on the periphery of the water filtering section, and filling a water-resisting material such as clay on the periphery of the water filtering section of the vertical tube well 30 above the water level line of the uppermost aquifer;

step G, arranging a water pumping device such as a submersible pump in the water storage section of the vertical pipe well 30, setting the start-stop control water level of the pump, and performing automatic positioning water pumping for pumping out water permeating into the vertical pipe well 30;

and H, when the foundation pit dewatering task is completed, plugging and sealing the vertical pipe well.

In step B, as shown in fig. 6, the bottom interface of the horizontal sand well 70 is moved down to the water barrier below the aquifer, and at this time, the function of cutting off the hydraulic connection between the inside and the outside of the foundation pit is provided, so-called inside and outside of the foundation pit refers to that the space between the horizontal sand well dewatering and dewatering structure and the foundation pit is the inside, the side of the horizontal sand well dewatering and dewatering structure far from the foundation pit is the outside, and the problem of "dewatering and non-dewatering" can be thoroughly solved by cutting off the hydraulic connection between the inside and the outside of. The vertical sand well in the horizontal sand well structure can lead the underground water in the aquifer where the vertical sand well is located into the horizontal sand well without any limiting condition, plays the role of a water seepage well and can drain the underground water of the aquifer through which the vertical sand well passes. Therefore, the design of the whole horizontal sand well structure ensures that all parts of the horizontal sand well structure are fully cooperated and closely matched, and the aim of dewatering and draining the foundation pit can be well realized.

As shown in fig. 7 to 17, in the construction of manufacturing the retaining wall ring 60 by expanding and stirring the sand column 80 in step D, the underwater soil mass expanding and stirring device is fixedly arranged at the lower end of the drill rod, the drill rod is a dual-pipe drill rod with a core pipe, the underwater soil mass expanding and stirring device comprises an outer pipe 1, an inner pipe 2, a cutting and stirring frame 3, a drill bit 4 and a slurry conveying system, the upper end of the outer pipe 1 is fixedly connected with the drill rod, the inner pipe 2 is vertically and slidably sleeved at the inner lower part of the outer pipe 1, the cutting and stirring frame 3 is circumferentially arranged between the outer pipe 1 and the inner pipe 2 in an array manner, and the drill bit 4 is fixedly arranged at the lower end of; a partition plate 5 is arranged at the upper part in the outer tube 1, a connecting core tube 6 is communicated above the partition plate 5, and the connecting core tube 6 and the outer tube 1 are coaxially and fixedly arranged; the cutting stirring frame 3 consists of an upper cutting plate 301 and a lower cutting plate 302, the upper end of the upper cutting plate 301 is hinged with the outer wall of the lower end of the outer pipe 1, the upper end of the lower cutting plate 302 is hinged with the lower end of the upper cutting plate 301, and the lower end of the lower cutting plate 302 is hinged with the outer wall of the lower end of the inner pipe 2; the slurry conveying system comprises an upper slurry outlet 7, a lower slurry outlet 8, an inverted T-shaped hole 9, a side through hole 10, a low-pass pipe 11, an upper through pipe 12 and a lower through pipe 13, wherein the upper slurry outlet 7, the lower slurry outlet 8, the inverted T-shaped hole 9 and the side through hole 10 are respectively arranged in an upper cutting plate 301, a lower cutting plate 302, a drill bit 4 and an inner pipe 2, one end of the upper slurry outlet 7 is positioned in the middle of the upper end of the upper cutting plate 301, the other end of the upper slurry outlet is positioned on the side surface of the lower end of the upper cutting plate 301, one end of the lower slurry outlet 8 is positioned in the middle of the lower end of the lower cutting plate 302, the other end of the lower slurry outlet is positioned on the side surface of the lower cutting plate 302, the cross section of the inverted T-shaped hole 9 is inverted T-shaped, the upper end of the inverted T-shaped hole 9 is positioned in the center of the top surface of the drill bit 4, the lower end of the circumferential side wall of the drill bit 4, the upper through pipe 12 and the lower through pipe 11 are both positioned in the outer pipe 1, one end of the upper through pipe 12 is communicated to the partition plate 5, the other end of the upper through pipe penetrates through the lower part of the outer pipe 1 and is communicated to the upper pulp outlet hole 7, the upper end of the lower through pipe 11 is communicated to the connecting core pipe 6, and the lower end of the lower through pipe is communicated to the upper end of the inverted T-shaped hole 9.

The inner diameter of the outer tube 1 is equal to the outer diameter of the inner tube 2.

The inner wall circumference array of outer tube 1 lower part is provided with the vertical guide slot of a plurality of, the outer wall circumference array of inner tube 2 upper portion is provided with the vertical conducting bar of a plurality of, conducting bar and guide slot one-to-one, and the cross sectional shape of conducting bar corresponds with the cross sectional shape of guide slot.

The outer tube 1 inside wall circumference array is provided with the vertical recess of a plurality of, the quantity of recess equals the quantity of last siphunculus 12, it is located the recess to go up siphunculus 12.

The lower part of the inner pipe 2 is sleeved with a plurality of positioning hoops 14, and the outer diameter of the positioning hoops 14 is equal to that of the outer pipe 1.

The side of the upper cutting plate 301 far away from the upper slurry outlet 7 and the side of the lower cutting plate 302 far away from the lower slurry outlet 8 are both provided with cutting edges, and the cutting edges of the upper cutting plate 301 and the lower cutting plate 302 are arranged in the same direction.

The specific construction steps of the underwater soil body spreading and stirring device are as follows:

a. determining the stirring expansion range: determining the shape, the size and the top-bottom elevation of the expanded stirring area according to the expanded bottom elevation, the expanded bottom space size and the thickness of the soil-slurry retaining wall ring to be set;

b. determining the size of the underwater soil body spreading and stirring device: determining the heights of the outer pipe 1 and the inner pipe 2 and the size of the cutting stirring frame 3 according to the maximum stirring expansion range;

c. selecting a drill rod: when the stirring height is equal to the height of the outer pipe 1, selecting a conventional drill rod; when the expansion stirring height is greater than the height of the outer pipe 1, the drill rod connected with the outer pipe 1 is preferably a helical blade drill rod, the sum of the total length of the helical blade drill rod and the height of the outer pipe 1 is not less than the height of the expansion stirring range, and the drill rods of other sections can be conventional drill rods or helical blade drill rods;

d. preparing slurry: comprehensively determining the curing strength and thickness of the soil-slurry retaining wall ring according to geological conditions and engineering requirements, and preparing slurry with matched initial setting time;

e. drilling a straight hole: drilling a straight hole to an upper height position in a stirring expanding range according to the standard requirement;

f. carrying out expanding and stirring: d, expanding and stirring the straight hole drilled in the step e through an underwater soil body expanding and stirring device;

g. taking soil: after the expansion and the agitation of the adjacent holes in the forward direction of the construction are finished, the soil in the expansion and agitation range is taken out by adopting a conventional soil taking and expanding device, and an outer ring formed by slurry is reserved in the expansion and agitation range, which is called a retaining ring 2001.

The two slurries prepared in step d should be determined for each individual slurry and for a reasonable initial setting time after mixing of the two slurries.

Step f, an underwater soil body spreading stirrer is conveyed to the bottom of the straight hole drilled in the step e through a drill rod, a cutting stirring frame 3 is opened to be in contact with the wall of the straight hole, two kinds of slurry prepared in the step d are conveyed to an upper through pipe 12 and a lower through pipe 11 through gaps between a core pipe of the drill rod and the inner wall of the drill rod respectively, the underwater soil body spreading stirrer is spun through the drill rod, an outer pipe 1 slides downwards along an inner pipe 2, the cutting stirring frame 3 is used for rotatably cutting the wall of the hole, the two kinds of slurry flow out from an upper slurry outlet hole 7 and a lower slurry outlet hole 8 respectively under pressure, enter a rotatably cut loose soil body, are further mixed with the soil body along with the stirring of the cutting stirring frame 3 and are gradually initially solidified to form a slurry-soil body, and meanwhile, the cutting stirring frame 3 is further; therefore, when the cutting stirring frame 3 is gradually opened to the maximum, namely when the cutting stirring frame 3 is gradually opened to the maximum, the pressure of a drill rod is increased, the drill bit 4 drills downwards, meanwhile, the cutting stirring frame 3 rotationally cuts soil around the hole with the maximum opening degree, slurry is continuously discharged to mix with the rotationally cut loose soil, and therefore the bottom elevation of the designed stirring range is reached; after the expansion stirring is finished, slowly lifting the underwater soil body expansion stirrer, stopping preparing slurry in the step d, conveying filling slurry with low strength, stirring and drawing back the cutting stirring frame 3 in the rotating process along with the slow lifting of the underwater soil body expansion stirrer, and reinforcing the bottom of the expansion stirring range by the slurry remained in the underwater soil body expansion stirrer; along with the arrival of the filling slurry, the filling slurry fills the space left by the underwater soil body agitator moving away, thereby maintaining the stability of the agitation expanding area.

When the agitator is arranged at the bottom of the hole, the drill bit 4 stops moving downwards due to the blockage of soil at the bottom of the hole, and the cutting agitator frame 3 is opened and touches the wall of the hole. Slurry conveying is started, a drill rod is spun, an outer pipe 1 of the expansion stirrer descends along a nesting surface between the outer pipe and an inner pipe 2, soil on the wall of a hole is cut and stirred by a cutting stirring frame 3, and slurry flows out from a slurry outlet hole along respective pipelines and paths under pressure and enters the soil loosened by rotary cutting. During the stirring immediately following the cutting plate, the slurry and the soil mass are further mixed and rapidly initially set and solidified, while the cutting stirring frame 3 is further opened. At this stage, due to the resistance of the soil body at the bottom of the hole, the downward resistance of the drill bit 4 is greater than the cutting and stirring resistance, and the spinning effect of the drill rod on the expansion stirrer mainly ensures that the cutting and stirring frame 3 is gradually opened to the designed opening degree, and the drill bit 4 rotates due to the compression, so that a certain amount of downward drilling can be generated. The larger the cone angle of the drill bit 4, the more dense the soil at the bottom of the hole, and the smaller this downward drilling amount. When the cutting and stirring frame 3 is gradually opened to the maximum, the pressure of a drill rod is increased, the drill bit 4 drills downwards, simultaneously the cutting and stirring frame 3 rotationally cuts soil around the hole with the maximum opening degree, slurry is continuously discharged from the slurry outlet hole to mix with the rotationally cut loose soil, and then the designed bottom elevation for stirring is reached, and then the underwater soil body stirrer is lifted out of the hole.

Since the slurry outlet hole is positioned near the hinge joint of the upper cutting plate 301 and the lower cutting plate 302, the slurry is best solidified at the position, namely, a hard ring layer with relatively high strength is formed at the periphery of the stirring expanding range, while the slurry is infiltrated into the stirring expanding range, the strength is relatively weak, but the integrity is enhanced to a certain extent, which just provides a very convenient condition for next-step bottom expanding soil extraction.

When the agitator is lifted after the agitation is finished, the agitator still needs to rotate in the original direction, and the original slurry conveying is stopped, and the agitator is changed into the agitator for conveying the filling slurry with low strength after solidification. At this time, as the stirring expander is slowly lifted up, the cutting stirring frame 3 is stirred and gathered in the rotating process, and the original slurry remained in the pipe just reinforces the bottom of the stirring expanding range. The subsequent filling slurry will fill the space left by the agitator, thus maintaining the stability of the agitator-extended area, especially the high-strength ring layer on the periphery. When the stirrer is lifted up, the lifting speed is required to be noticed, and too high lifting speed can cause the bottom of the stirrer to form too large vacuum suction force, so that the formation of the mortar wall protecting ring 2001 is adversely affected.

In the construction process of the horizontal sand well 70 around the foundation pit 40, the vertical sand well 20 and the drilling holes of the sand column 80 below the vertical sand well are constructed one by one in advance, the gravel filling operation in the holes is carried out later, and no less than 2 hole sites need to be spaced between the vertical sand well 20 and the holes of the sand column 80 which are filling gravel and the holes of the space of the sand column 80 which is reaming.

In step F, the vertical tube well 30 is composed of a water filtration section and a water storage section. The reaming of the drilling of water filtering section is with the pore-forming of vertical sand well 20 and the reaming of 80 sections of sand column, and the pore-forming of water storage section is with the pore-forming of vertical sand well 20, and its concrete construction step is as follows:

i, forming a space with the vertical sand well 20 and the sand column 80 on the hole site of the vertical tube well 30 according to the previous description steps, wherein the space of the sand column 80 is preferably extended downwards by 30-50 cm on the original design scheme;

ii, after the spaces of the vertical sand wells 20 and the sand columns 80 on the two sides of the vertical pipe well 30 are formed, adopting a conventional soil taking and drilling method with the vertical sand wells 20 to take soil from the bottom surfaces of the spaces of the sand columns 80 downwards and drill the soil to the designed bottom elevation of the vertical pipe well 30;

iii, descending the water storage pipe section by section until the orifice of the water storage pipe is positioned at the bottom interface of the sand column 80 space or slightly lower than the bottom interface; then lowering the water filtering pipe to the orifice, wherein the bottom of the lowest water storage pipe is in a closed state and is impermeable;

and iv, gaps exist among the outer pipe walls of the water storage pipe and the water filtering pipe and the inner wall of the drill hole, and the gaps are filled by feeding. Because the water storage section is impermeable, the filling material of the gap can be impermeable material or the same filling material as the vertical sand well 20 or the sand column 80. When the water storage section is lowered into the aquifer below the lower aquifer, soft fluid impervious material such as thick mud or clay slurry doped with expanding agent and cement is used, and the filling can be conveyed directionally and quantitatively through the small-diameter PVC pipe which is arranged on the outer wall of the water storage pipe and is lowered to the bottom of the hole along with the water storage pipe until the upper end of the filling of the water storage section reaches the top of the water storage pipe or reaches a height which can cut off the hydraulic connection between the groundwater of the lower aquifer and the groundwater of the aquifer below the lower aquifer, so as to prevent multiple pumping and protect the groundwater resources from being polluted. The wall of the water filtering section and the drill hole are filled at intervals, the filling can be carried out before the sand columns 80 on the two sides are filled with the filling materials, and the filling materials correspond to the vertical sand well 20 and the sand columns 80. The part of the water filtering section above the water level of the uppermost aquifer is filled with water-proof materials such as clay to prevent ground water from filling;

and v, after the construction of most of the precipitation structures is finished, washing the vertical pipe well 30 according to the standard requirement, and submerging a pumping device such as a water pump for pumping and draining water.

Example four

On the basis of the third embodiment, as shown in fig. 18, in step a, if the aquifer determined by surveying the construction position of the foundation pit is one layer, the first aquifer 100 is the lower aquifer, and the horizontal sand wells 70 are all located in the lower aquifer.

EXAMPLE five

On the basis of the third embodiment, in the step a, if one or more aquifers are provided above the lower aquifer of the foundation pit engineering, and the single horizontal sand well dewatering and dewatering structure cannot dewater the aquifer and has a serious influence on the foundation pit engineering construction, one or more horizontal sand wells 70 need to be additionally provided in the one or more aquifers, the additionally provided horizontal sand wells 70 correspond to the horizontal sand wells 70 of the lower aquifer, and the bottom interface of the additionally provided horizontal sand wells 70 is arranged in the water barrier below the aquifer and is used for cutting off the hydraulic connection between the aquifers inside and outside the foundation pit. Thus, the multi-layer horizontal sand well structure forms a sand well structure in a horizontal and vertical grid shape, as shown in fig. 19.

In this embodiment, the lower aquifer is the third aquifer 300, the horizontal sand wells 70 are arranged in both the third aquifer 300 and the second aquifer 200, the two horizontal sand wells 70 correspond to each other, and the lower horizontal sand well 70 is entirely positioned in the lower aquifer. Compared with the above embodiment, the construction of the sand well structure is only different in that a single vertical sand well is constructed, at the moment, the hole drilling and expanding construction sequence is from top to bottom, namely, straight hole drilling-bottom expanding-straight hole drilling-bottom expanding, namely, the hole expanding of the upper horizontal sand well 70 can be completed firstly by adopting the stirring expanding device and the conventional soil taking and hole expanding device, then the hole expanding of the lower multi-section horizontal sand well 70 is constructed sequentially from bottom to top, and then the gravel sand material with high permeability is filled sequentially from bottom to top.

To the situation of this kind of multilayer aquifer rich water in the foundation ditch engineering, the dewatering effect of the perpendicular well point dewatering method of wide use among the prior art is unsatisfactory, even improve the effect through reducing the well point interval by a wide margin, but the shortcoming of perpendicular well point dewatering still exists, "dredge not do" problem and still be difficult to avoid, and the utility model discloses an adopt the form of multilayer horizontal sand well 70 can solve this problem betterly in this embodiment to realize the mesh that the quick dewatering of foundation ditch dredges.

EXAMPLE six

This embodiment is substantially the same as the fifth embodiment, and the same points are not repeated, except that in step B, when it is calculated that the bottom interface of the horizontal sand well 70 in the lower aquifer is located at or near the bottom interface of the third aquifer 300, the aquifer in this state is likely to become a "dry-sparse" aquifer, and in order to avoid this "dry-sparse" situation, the bottom interface of the horizontal sand well 70 is moved downward into the aquifer below the aquifer, that is, as shown in fig. 20, the lower horizontal sand well 70 is partially located in the lower aquifer, and the bottom interface of the horizontal sand well 70 is lower than the bottom interface of the lower aquifer and is located in the aquifer below the lower aquifer.

The above-mentioned embodiments are merely preferred embodiments of the present invention, and not intended to limit the scope of the present invention, so that equivalent changes or modifications made by the structure, features and principles of the present invention should be included in the claims of the present invention.

Claims (7)

1. The utility model provides a ring foundation ditch horizontal sand well precipitation unwatering structure, a serial communication port, include vertical sand well (20) that a plurality of encircleed foundation ditch (40) interval and at least one horizontal sand well (70) that encircle foundation ditch (40) and set up, horizontal sand well (70) are located the aquifer at foundation ditch (40) place, and horizontal sand well (70) link to each other with vertical sand well (20), and horizontal sand well (70) still are connected with a plurality of vertical tube well (30), a plurality of vertical tube well (30) set up around foundation ditch (40) interval, and vertical tube well (30) are including water filtering section and water storage section, water filtering section and water storage section set gradually from top to bottom, and the boundary line of water filtering section and water storage section is located on the bottom boundary of below horizontal sand well (70) or is less than the bottom boundary of below horizontal sand well (70), be provided with pumping equipment in the water storage section.

2. The dewatering and dewatering structure for the horizontal sand well of the ring foundation pit according to claim 1, wherein the horizontal sand well (70) comprises a plurality of cylindrical sand columns (80) which are sequentially connected end to end and a wall protecting ring (60) which is positioned above the sand columns (80), partial intersection exists between every two adjacent sand columns (80), and the sand columns (80) and the vertical sand well (20) are concentrically arranged.

3. The structure for dewatering and draining the horizontal sand well of the annular foundation pit according to claim 2, wherein the number of the horizontal sand wells (70) in the lower aquifer where the foundation pit (40) is located is one, and the horizontal sand well (70) forms a dewatering and wetting line which is 0.5m lower than the bottom of the foundation pit (40).

4. A horizontal sand well dewatering and dewatering structure for an annular foundation pit according to claim 3, wherein the horizontal sand well (70) located in the lower aquifer where the foundation pit (40) is located in the lower aquifer in its entirety.

5. A horizontal sand well dewatering and dewatering structure for an annular foundation pit according to claim 3, wherein the horizontal sand well (70) located in the lower aquifer where the foundation pit (40) is located is partially located in the lower aquifer, and the bottom interface of the horizontal sand well (70) is lower than the bottom interface of the lower aquifer and is located in the water barrier below the lower aquifer.

6. A horizontal sand well dewatering and draining structure for an annular foundation pit according to claim 3, wherein one or more horizontal sand wells (70) are arranged in one or more aquifers above a lower aquifer where the foundation pit (40) is located, the bottom interface of the horizontal sand well (70) in a non-lower aquifer is located in a water barrier below the aquifer where the foundation pit (40) is located, and the plurality of horizontal sand wells (70) in the aquifer where the foundation pit (40) is located correspond to each other.

7. The dewatering and dewatering structure of the horizontal sand well of the ring foundation pit according to claim 2, wherein the horizontal sand well (70) is a cylindrical structure filled with high water permeability material, the vertical sand well (20) is a two-section structure, the lower section of the vertical sand well (20) is a cylindrical structure filled with high water permeability material, the upper section of the vertical sand well (20) is located above the water level line of the aquifer at the uppermost layer, and the upper section of the vertical sand well (20) is a cylindrical structure filled with water impermeable material.

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