CN209723033U - Pipe jacking working well applicable to desert waterless sand layer area - Google Patents

Abstract

The utility model provides a pipe jacking working well suitable for the desert anhydrous sand layer area. A plurality of bored cast-in-place piles are evenly arranged along the circumference of the working well, and the plurality of bored cast-in-place piles surround the center of the working well to form the main enclosure of the working well. There is a crown beam above the bored pile body. The circular crown beam and the working well are concentric structures. The inner lining is located inside the bored pile, and the inner lining is arranged vertically along the depth direction of the working well. The hidden beams are embedded in the lining and are arranged at intervals from top to bottom along the length of the lining. The bottom plate is located at the bottom of the working well. The bottom of the bottom plate is provided with a bottom-reinforcing rotary jetting pile. At the entrance and exit positions, there are reinforced rotary jet piles at the entrance. The bored pile of the utility model can ensure the stability of the soil body during the excavation process, and can bear the large reaction force required for the pipe jacking construction; the inner lining of the utility model can increase the stability of the sand between the piles, and reduce the horizontal load Evenly pass to bored piles.

Description

A kind of pipe jacking working well suitable for desert anhydrous sand area

technical field

The utility model belongs to the technical field of pipe jacking construction, and in particular relates to a pipe jacking working well suitable for an anhydrous sand layer in the desert.

Background technique

Pipe jacking construction is a pipeline facility construction technology with no or less excavation. Pipe jacking construction is an underground pipeline construction method developed after shield construction. It does not require excavation of the surface layer, and can cross roads, railways, rivers, ground buildings, underground structures and various underground pipelines. With the further acceleration of the urbanization process, the demand for underground pipelines in my country is also increasing year by year. Coupled with the enhancement of people's awareness of environmental protection, pipe jacking technology plays an increasingly important role in the construction of underground pipelines in my country.

In the process of pipe jacking construction, in order to reduce the construction jacking force of the pipe jacking, the method of segmented construction is mostly adopted, and vertical working wells and receiving wells need to be set up during the segmented construction process. In addition to providing the construction space required by machinery and personnel, the pipe jacking shaft should also provide the reaction force required for the jacking of the pipe, so the wall of the pipe jacking shaft often bears a large horizontal jacking force. When the pipe jacking construction is located in the desert anhydrous sand layer, the jacking force required for the pipe jacking is very large, which brings great difficulties to the design and construction of the shaft. However, the structure and construction method of the current working well cannot meet the requirements of pipe jacking in the desert anhydrous sand layer.

Therefore, it is necessary to provide an improved technical solution for the deficiencies of the above-mentioned prior art.

Utility model content

The purpose of this utility model is to overcome the need for large horizontal jacking force during the pipe jacking construction in the desert anhydrous sand layer area in the prior art, but the current working well structure and construction method cannot meet this requirement.

In order to achieve the above object, the utility model provides the following technical solutions:

A pipe-jacking working well suitable for desert anhydrous sand layer areas, the working well comprises:

A plurality of bored cast-in-place piles are evenly arranged along the circumference of the working well, and a plurality of the bored cast-in-place piles form a first well wall around the center of the working well, which is used for the main enclosure of the working well and force;

A crown beam, a crown beam is arranged above the first well wall body, and the circular crown beam and the working well are concentric circle structures;

an inner lining, the inner lining is located on the inner side of the bored cast-in-place pile, and the inner lining is vertically arranged along the depth direction of the working well to form a second well wall body, which is used for the auxiliary enclosure and stress of the working well;

Concealed beams, the concealed beams are embedded on the inner lining and are arranged at intervals from top to bottom along the depth direction of the inner lining;

a bottom plate, the bottom plate is located below the inner lining, and the periphery of the bottom plate is connected with the inner side wall of the bored pile;

The bottom reinforced rotary jet piles are arranged below the bottom plate, and the bottom reinforced rotary jet piles are arranged in a grid-like full house;

The hole-reinforced rotary jetting pile is provided with a hole-reinforced rotary jetting pile on the outer side of the bored cast-in-place pile, and the hole-reinforced rotary jetting pile is located at the entrance and exit of the pipe jacking pipe section of the working well.

As mentioned above, it is suitable for pipe jacking working wells in desert anhydrous sand areas. Preferably, the thickness of the lining is 0.5m-0.8m, and the interior of the lining is provided with dark beams at intervals of 4m-6m from top to bottom.

As mentioned above, it is suitable for pipe jacking working wells in desert anhydrous sand layers. Preferably, the thickness of the bottom reinforced rotary jetting pile is 2m-6m, and the overlap range is 0.2m-0.4m.

As mentioned above, it is applicable to the pipe jacking working well in the desert anhydrous sand layer. Preferably, the width of the concealed beam is the same as the thickness of the inner lining, and the height of the concealed beam is 0.5m-0.9m.

As mentioned above, it is suitable for pipe jacking working wells in desert anhydrous sand layers. Preferably, a first cushion layer is also provided at the connection between the inner lining and the crown beam, and the first cushion layer is a plain concrete cushion with a thickness of 100mm to 200mm. Floor.

As mentioned above, it is suitable for pipe jacking working wells in desert anhydrous sand layers. The second cushion layer is used to support the bottom plate formwork.

Any one of the above 1 to 6 is applicable to the construction method of the pipe jacking working well in the desert anhydrous sand layer area, preferably, the construction method comprises the following steps:

S1, carry out the construction of bored piles;

S2, the construction of the crown beam is carried out after the concrete strength of the bored pile reaches the design strength in step S1;

S3, in step S2, after the concrete strength of the crown beam reaches the design strength, the excavation of the soil body in the working well is carried out, and the construction of the concealed beam and the inner lining is carried out;

S4, carry out the construction of the bottom-reinforcing rotary jetting pile, the bottom plate, and the hole-hole reinforcing rotary jetting pile.

As mentioned above, it is applicable to the construction method of the pipe jacking working well in the desert anhydrous sand layer area. Preferably, the step S1 includes the following steps:

S101, using mud retaining wall or steel pipe retaining wall method to apply the pile hole of bored pile;

S102, hoist the pile foundation reinforcement cage into the pile hole of step S101;

S103, pour the pile foundation concrete into the pile foundation reinforcement cage of step S102.

As mentioned above, it is applicable to the construction method of the pipe jacking working well in the desert anhydrous sand layer area. Preferably, the step S2 specifically includes the following steps:

S201, excavating the soil at the crown beam;

S202, tie the crown beam reinforcement in the excavated crown beam foundation pit;

S203, construct the crown beam formwork on the crown beam reinforcement;

S204, pouring the crown beam concrete.

As mentioned above, it is applicable to the construction method of the pipe jacking working well in the desert anhydrous sand layer area. Preferably, the step S3 includes the following steps:

S301, excavating the soil in the working well;

S302, planting reinforcement on the shaft wall of the working well at the excavated soil body;

S303, erecting a lining template;

S304, the concrete construction of the inner lining and the concealed beam is carried out.

Compared with the closest prior art, the technical solution provided by the present utility model has the following excellent effects:

The new pipe jacking shaft of the utility model can not only meet the construction space required by machinery and personnel, but also provide a large horizontal reaction force for pipe jacking construction; the inner lining of the bored pile of the utility model can increase the sand between the piles The stability of the soil, the inner lining can increase the stability of the sand between the piles, and evenly transmit the horizontal load to the bored piles, and the hidden beams set inside the lining can connect the bored piles into a whole and bear the force together; The high-pressure rotary jet pile of the utility model can ensure that the construction personnel can realize the bottom sealing of the vertical shaft on the ground, thereby increasing the structural safety and the construction convenience. At the same time, the pile diameter and pile depth of the bored piles can be selected in a large range, there is no soil squeeze effect, and the vertical and horizontal bearing capacities are high. In addition, it can also provide a larger reaction force required for the pipe jacking of the starting working well.

Description of drawings

1 is a schematic structural diagram of a working well according to an embodiment of the present utility model;

Fig. 2 is the plan layout drawing of the foundation pit lining of the embodiment of the present utility model;

FIG. 3 is a schematic diagram of the positional relationship between the crown beam and the first cushion layer in FIG. 1 .

In the picture: 1. Crown beam; 2. Bored cast-in-place pile; 3. Concealed beam; 4. Reinforced jetting pile at the hole; 5. Inner lining; 6. Second cushion; 7. Reinforced jetting pile at the bottom of the well; 8 , bottom plate; 9, the first cushion; 10, pipe joints.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention belong to the protection scope of the present invention.

The present utility model will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments. It should be noted that the embodiments of the present invention and the features of the embodiments may be combined with each other under the condition of no conflict.

As shown in Figures 1-3, the utility model provides a pipe jacking working well suitable for desert anhydrous sand layer areas, and the working well includes:

Bored piles 2, a plurality of bored piles 2 are evenly arranged along the circumference of the working well, and a plurality of bored piles 2 form a first well wall around the center of the working well, which is used for the main enclosure and the working well. The first well wall body is used to bear the reaction force required by the pipe jacking construction and ensure the stability of the entire working well.

Crown beam 1, a crown beam 1 is arranged above the first well wall body, and the circular crown beam 1 is in a concentric structure with the working well.

The inner lining 5 is located on the inner side of the bored pile 2. The inner lining 5 is arranged vertically along the depth direction of the working well to form a second well wall, which is used for the auxiliary enclosure and stress of the working well. The thickness is 0.5m-0.8m, and the inner lining 5 is provided with dark beams 3 at intervals of 4m-6m from top to bottom. The annular dark beam 3 and the inner lining 5 form a stable force-bearing structure, which can greatly increase the overall rigidity and bearing capacity of the working well.

The hidden beam 3, the hidden beam 3 is embedded in the inner lining 5 and is arranged at intervals from top to bottom along the length direction of the inner lining 5, the width of the hidden beam 3 is the same as the thickness of the inner lining 5, and the height of the hidden beam 3 is 0.5m～ 0.9m, a first cushion layer 9 is also provided at the connection between the inner lining 5 and the crown beam 1, and the first cushion layer 9 is a plain concrete cushion layer with a thickness of 100mm-200mm.

The bottom plate 8 is located below the inner lining 5 , and the periphery of the bottom plate 8 is connected with the inner side wall of the bored pile 2 .

Bottom reinforced rotary jetting piles 7, bottom reinforced rotary jetting piles 7 are arranged below the bottom plate 8, and the bottom well reinforced rotary jetting piles 7 are arranged in a grid-like full house, that is, a grid-shaped bottom-well reinforced rotary jetting pile is arranged at the bottom of the well. The spray pile 8 is also provided with a second cushion layer 6 between the bottom plate 8 and the bottom reinforced rotary spray pile 7. 180mm, 190mm, 200mm), used to support the bottom plate 8 formwork.

The hole-reinforced rotary jetting pile 4 is provided on the outside of the bored cast-in-place pile 2, and the hole-reinforced rotary jetting pile 4 is located at the entrance and exit of the pipe jacking pipe section 10 of the work well; the thickness of the bottom-well reinforced rotary jetting pile 7 It is 2m to 6m, and the overlap range is 0.2m to 0.4m.

The utility model also provides a construction method suitable for a pipe jacking working well in an anhydrous sand layer area of the desert, and the construction method comprises the following steps:

S1, carry out the construction of the bored pile 2, and step S1 includes the following steps:

S101 , the pile holes of the bored cast-in-place pile 2 are formed by the method of mud retaining wall or steel pipe retaining wall.

S102, the pile foundation reinforcement cage is hoisted into the pile hole of step S101.

S103, pour the pile foundation concrete into the pile foundation reinforcement cage of step S102.

S2, the construction of the crown beam 1 is carried out after the concrete strength of the bored pile 2 reaches the design strength in step S1, and step S2 specifically includes the following steps:

S201, excavate the earthwork of crown beam 1, the depth of the foundation pit of crown beam 1 is 3m below the ground, there is no groundwater within the excavation range of the foundation pit, there are no other structures and buildings around the foundation pit, and the soil layer of the crown beam 1 foundation pit is loose, medium Dense sandy soil, no load on the top of the slope, the excavation depth is 3m, and the excavation is carried out with a grading ratio of 1:1.

S202, tie the crown beam 1 reinforcement in the excavated crown beam 1 foundation pit, chisel the cast-in-place pile to the design elevation, straighten the steel bar at the pile head, artificially level the sand and soil within 600mm of the periphery to 150mm below the pile top, and Pour 100mm thick C20 concrete cushion. The chiseled pile head is embedded in the crown beam 1 for 50mm, and the main reinforcement of the cast-in-place pile is anchored into the crown beam 1 for 770mm. Double rows of Φ18@100 steel bars are reserved at the connection between the inner side of the crown beam 1 and the lining 5 wall (the vertical bars on the inner side of the lining wall, the Φ16@150 steel bars are reserved for the receiving well, and the Φ18@100 steel bars are reserved for the working well) and inserted into the sand. Not less than 1m. The transverse main bars of crown beam 1 are connected by welding, and the stirrups are connected by binding, and the thickness of the protective layer is 40mm.

S203, construct the crown beam 1 template on the crown beam 1 reinforcement, and construct the crown beam 1 template on the crown beam 1 reinforcement: the template is erected on both sides of the wooden mold, the splicing place is nailed with wooden squares, and the beam wall is paired with Q235M14 The bolts (with 3 pieces of 3mm water-stop steel sheets) are reinforced by 400×400mm, the bolt caps cover the vertical corrugation of the steel pipe, and the horizontal corrugation of the steel pipe is connected in three circles, and the vertical spacing is 800mm and is set at the bolt reinforcement.

S204, the crown beam 1 concrete is poured, and the crown beam 1 scaffold needs to be erected before the crown beam 1 concrete is poured. The outside of the crown beam 1 adopts double-row floor-standing scaffolding, and the interior adopts the full-house type scaffolding construction, and the fastener type scaffolding is used for erection. Its erection size It is: the vertical distance of the vertical pole is 1.5m, the horizontal distance of the vertical pole is 1.5m, the step distance of the vertical pole is 1.8m, the height of the inner and outer scaffolding of the crown beam 1 is 3.6m; the length of the inner bent frame from the wall plate is 0.35m, the large crossbar is at the bottom, and the number of small crossbars lapped on the large crossbar is 2; the type of steel pipe used is Φ48.3×3.6; the connection method between the crossbar and the vertical rod is a single fastener; The sliding capacity factor is 0.8. The crown beam 1 is poured by using a truck pump to transport C35 commercial concrete. During the pouring, the vibrating rod is used to compact it, and the top of the crown beam 1 is smoothed and smoothed.

In the construction of crown beam 1, the following issues should be paid attention to:

①When the crown beam 1 is constructed, if the size of the working face in the foundation pit is not enough, the foundation pit needs to be enlarged and grading at a ratio of 1:1.2, and sand backfill cannot be used as a shielding surface.

② Reinforcement binding can only be carried out when the cushion concrete reaches the design strength.

③ Before pouring concrete, first check that the scaffolding is erected, the formwork support must be firm, the tie bolts must be tightened, and the sundries in the form must be cleaned up. The free fall height of concrete shall not exceed 2m.

④Before the scaffolding is erected, lay out the line strictly according to the construction plan, set the base, the backing plate and the position of the calibration pole, and set up from the middle part to both sides in a circle. Connecting wall rod; scissors braces and scaffolding are erected synchronously, set on the outer facade of the scaffolding, and continuously arranged along the height of the scaffolding, the angle between the inclined rods and the ground is 45° to 60°, and the two ends of the inclined rods of the scissors braces are connected with rotating fasteners. After the vertical pole or large horizontal bar of the scaffold is fastened, add 2 to 4 fastening points in the middle. The overlapping length of all scissor braces shall not be less than 1m, and shall be fixed by at least 3 sets of fasteners; the ends of the intersecting and protruding ends of the scaffolding rods shall be greater than 10cm to prevent the rods from slipping. Protective railings and safety nets are installed within each step distance.

⑤ Before using the vibrator, all parts must be carefully checked, and the operator must wear insulating gloves and insulating shoes; when using the vibrator, a trial run must be performed first, and it can be used formally after confirmation; the vibrator must sink into and pull out of the concrete naturally , can not force hard plug, hard pull. When vibrating, the vibrating rod must be twitched up and down to ensure uniform vibrating. The time of each vibrating must be appropriate. It is necessary to prevent the vibrating from being unrealistic, and to prevent the segregation of the stones in the lower layer and the cement mortar after over-vibration, which will affect the performance of the concrete. For quality, the vibrating time of each insertion point is guaranteed to be 20-30 seconds. When the concrete surface is level and there is a uniform grout and no air bubbles, it does not sink significantly, indicating that it has been vibrated, that is, stop vibrating.

S3, in step S2, after the concrete strength of the crown beam 1 reaches the design strength, the construction of the concealed beam 3 and the inner lining 5 is carried out, and the step S3 includes the following steps:

S301 , excavating the soil in the working well, the construction of the crown beam 1 is completed, and after the concrete strength reaches the design strength, the earthwork excavation of the lower lining 5 is carried out. There is no groundwater within the range of the inner lining 5 structure. According to the actual situation on site, the earth excavation of inner lining 5 is divided into two methods.

Method 1: The earthwork of the foundation pit within 15m below the ground is directly excavated with a long-arm excavator, and the excavated earthwork is pushed to the off-site with a bulldozer.

Method 32: The foundation pit with a depth of more than 15m below the ground is excavated by manual excavation with a small excavator, and a WY15 hydraulic backhoe (0.3m ³ ) is selected. The excavator is mainly used for the excavation of the foundation pit. Excavation, manual cooperation to excavate the places that cannot be excavated by machinery. The one-time excavation depth is controlled within 1.8m, and the height of each section in the loose sand layer area should not be greater than 1m. First excavate from the middle, and then excavate to the surrounding areas. The excavated earth is loaded into the steel earth bucket, hoisted out of the well by a truck, and pushed out of the site by a bulldozer.

In addition, the concealed beam 3 and the inner lining 5 are constructed at the same time: a ring-shaped concealed beam 3 with a height of 700 mm and a width of 500 mm is arranged every 4.5m of the inner lining 5 structure, and 8 Φ16 horizontally spaced 275 mm vertical For planting bars with a spacing of 500mm, the length of the bars anchored into the pile is 560mm, and the exposed 440mm. After the pull-out strength of the planted bars reaches the design requirements, the concealed beam 3 steel bars can be bound, and the concealed beam 3 steel bars are connected by welding, and the thickness of the protective layer is 40mm. The embedded iron of the hidden beam 3 and the embedded iron of the crown beam 1 are buried in the same way and on the same vertical line. The thickness of the concealed beam 3 is the same as that of the inner lining 5, and the vertical and horizontal stirrups of the reinforcing bars are increased compared with the inner lining 5. The installation method of the template is the same as that of the inner lining 5 structural template, and the concrete strength is C35.

S302, plant reinforcements on the well wall of the working well at the excavated soil body. When the inner lining 5 is constructed in the reverse method, the formwork is a single-sided formwork. When reinforcing, the screw can not be directly pulled in the same way as the general formwork support. Reinforcing bars are planted on the pile body as the in-wall fixed end of the pull rod.

After the completion of the erection of 5 scaffolds for each section of the lining in the well, clean the soil on the surface of the cast-in-place piles, and plant reinforcing bars according to the spacing between the tie bolts. The diameter of the reinforcing bars is 16mm. Carry out the pull-out test and proceed to the next process only after the test is qualified.

S303, set up lining 5 templates:

1) Steel bar processing: ① Steel bars are processed and batched in the steel bar shed, and then bound and formed after being transported to the construction site. ②Before the steel bar is processed, the surface of the steel bar should be cleaned of oil stains, rust, paint stains, ice cubes, snow and other sundries.

2) Steel bar connection: The steel bar connection is divided into vertical and horizontal steel bar joints, all of which are connected by single-sided welding, and the welding length is 10d.

3) Reinforcement installation: ①After the manual trimming of earthwork excavation is completed, the reinforcement reinforcement for wall protection shall be bound immediately. The construction method of pre-cutting and underground binding is adopted. When the steel bars of the first section of the inner lining 5 are made, the vertical steel bars of the second section of the inner lining 5 are reserved. When binding, first drive the vertical steel bar into the sand, and the depth of the sand is not less than twice the length of the vertical steel bar lap welding, and ensure that it is vertical. The spacing of the reinforcing bars is according to the design requirements, and then the horizontal horizontal reinforcing bars are bound. The horizontal reinforcing bars are outside, and the vertical 7 reinforcing bars are inside. Between the double rows of reinforcing bars, tie bars and reinforcing bar ladders are arranged to bind them in place, and the connections of the vertical reinforcing bars are all welded. ②When the reinforced concrete lining 5 is opened, the wall reinforcement should be cut off, and the reinforcement reinforcement should be set around the opening, the area of which is not less than the area of the cut steel reinforcement, and each side is not less than 4 main reinforcement, and exceeds the hole diameter by 800-1000mm on each side. ③ Use cement mortar pads to control the protective layer. ④ When making the steel bars of the bottom plate 8, reserve the steel bars of the last section of the shaft wall. ⑤ After repairing the formwork, trim the protruding wall steel bars, and tie a temporary positioning bar. When the displacement and deformation of the steel bars are found, they should be adjusted in time.

4) Formwork project: ①The lining 5 formwork system is composed of 13mm thick seven-layer plywood, square wood, steel pipe and tension bolts. ②The formwork reinforcement is composed of vertical wooden squares and horizontal steel pipes (Φ48.3×3.6), the distance between vertical corrugated squares is 250mm, and the distance between horizontal corrugated steel pipes is 500mm; On the planting bar, the other end is tied with the horizontal steel pipe to strengthen the section of the template. The horizontal spacing of the screws is 500mm and the vertical spacing is 500mm. ④ The structure of the inner lining 5 is constructed in the reverse way. When installing the lower section of the inner lining 5 formwork, the concrete of the upper section of the inner lining 5 has been poured, so special treatment should be done to the upper and lower joints. The upper mouth of the side mold at the joint is provided with a cup-shaped feeding port, which is 300mm higher than the joint of the upper and lower sections, and the width is 5250mm from the lining of the well. The concrete is fed from the feeding port. ⑤ Template installation process: template making → initial fixing of template with bolts → vertical corrugated installation → horizontal corrugated installation → mold adjustment and mold setting.

S304, carry out the concrete construction of the inner lining 5 and the concealed beam 3:

①Concrete transportation: In order to ensure the pouring quality of the lining 5 structure, commercial concrete is used for the lining 5 concrete, which is transported into the site by a concrete truck, and the lining 5 structure is poured by a concrete pump truck.

②Concrete pouring: The concrete grade of the lining 5 mechanism is C35, the wall thickness of the lining 5 is 500mm, and the thickness of the bottom plate 8 is 1000mm. Due to the reverse construction method, the structural wall is poured in multiple times. The construction joints shall be treated with oblique joints. The total time of concrete pouring and intermittent shall not exceed the initial setting time of concrete. The concrete of the lining 5 of the same section must be continuously poured, and the upper layer of concrete must be poured before the initial setting of the bottom concrete.

③ Vibration when pouring concrete: When vibrating, it should be inserted quickly and slowly pulled out; the wall panel should be vibrated in the direction, and the upper layer should be inserted into the lower layer ≥50mm when vibrating. The moving distance of the vibrating rod is less than or equal to 50cm. The vibrating time of each insertion point is 25 ± 5s, and the vibrating time is determined by observing (the concrete surface is swelled with slurry, no longer sinks significantly, and no air bubbles appear). The distance between the vibrator and the template is less than or equal to 20cm. When pouring concrete from the construction joint, do not directly approach the joint edge to unload the material. When vibrating, advance from far to near to the construction joint, stop vibrating at a distance of 900mm±100mm from the joint edge, and manually strengthen the concrete here. Vibrate to bind tightly.

④ Precautions when pouring concrete: In order to ensure that the formwork does not move or deform, the concrete pouring strength needs to be strictly controlled, and the pouring strength should be controlled at 1.5m/h. The free height of the concrete falling from the height shall not exceed 2m, and the vibrating chute shall be used when the vertical structure height of the pouring exceeds 3m. drop the concrete.

⑤Concrete curing: Concrete curing shall be carried out within 12 hours after the completion of concrete pouring, and it must be cured for 3 days after the completion of the pipe jacking construction. Cover with plastic wrap and water to keep it moist, keep the concrete wet and pour. Before the finished concrete strength is less than or equal to 1.2Mpa (determined by experiments under the same conditions), no climbing or other operations are allowed.

S4, carry out the construction of the bottom reinforced rotary jetting pile 7, the bottom plate 8, and the hole reinforced rotary jetting pile 4, the construction of the hidden beam 3 and the inner lining 5 wall is stopped until the top elevation of the pipeline is above, and the bottom plate 8 is constructed after the well cushion construction is completed. Reinforced with remaining lining 5 walls and openings. Cushion, bottom plate 8, and foundation pit shall be closed in time after excavation to the bottom to ensure construction safety.

(1) Cushion construction: The cushion is poured with C20 plain concrete with a thickness of 200mm. Before construction, level and clear the debris at the bottom of the pit. The height of concrete pouring is controlled within the design elevation. After the construction is completed, personnel cannot directly step on it.

(2) Bottom plate 8, remaining lining 5, hole reinforcement construction: ① Bottom plate 8 steel bar binding: Bottom plate 8 steel bars are bound in two layers, the horizontal and vertical spacing of the lower steel bars is Φ22@150 protective layer 40mm, and the two ends of the steel bar are 90° upward with 350mm hooks ;The horizontal and vertical spacing of the upper steel bars is Φ22@120 (the working well is Φ22@100), the protective layer is 35mm, the double-layer steel bars extend into the wall for ≥12d, and at least reach the center line of the wall, and the steel bars are connected in the form of binding and lap.

②The last section is lined with 5 walls and the openings are reinforced with steel bars: the last section of the lining 5 wall is anchored with vertical steel bars into the bottom plate 8, and the 90° hook of the inner layer of steel bars is anchored into the bottom plate 8. The length is 36d, and the connection with the bottom plate 8 is set. 4Φ25 reinforcing ribs are connected laterally. The inner lining 5 wall is widened by 800mm at the designed opening, and the reinforcement reinforcement is set at the opening. The remaining final lining 5 concrete is reinforced with prefabricated steel formwork. The pouring method is the same as the construction method of the upper lining 5 wall.

To sum up, the inner lining 5 and the concealed beam 3 of the working well in the present invention are located on the inner side wall of the bored pile 2 at intervals, and the inner lining 5 and the concealed beam 3 form a stable structure, which can strengthen the inner side of the working well. The compressive strength of the whole wall, and the lining 5 and the concealed beam 3 are constructed at the same time, which is convenient to improve the efficiency of construction. In addition, the overall construction efficiency of the construction method of the present invention is relatively high.

The above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention are all within the scope of the present invention. Within the scope of protection of the new type of pending claims.

Claims (6)

1. a pipe jacking working well suitable for desert anhydrous sand layer area, is characterized in that, described working well comprises: A bored cast-in-place pile, a plurality of the bored cast-in-place piles are evenly arranged along the circumference of the working well, and a plurality of the bored cast-in-place piles form a first well wall around the center of the working well; A crown beam, a crown beam is arranged above the first well wall body, and the circular crown beam and the working well are concentric circle structures; an inner lining, the inner lining is located on the inner side of the bored cast-in-place pile, and the inner lining is vertically arranged along the depth direction of the working well to form a second well wall body; Concealed beams, the concealed beams are embedded in the inner lining and are arranged at intervals from top to bottom along the depth direction of the inner lining; a bottom plate, the bottom plate is located below the inner lining, and the periphery of the bottom plate is connected with the inner side wall of the bored pile; The bottom reinforced rotary jet piles are arranged below the bottom plate, and the bottom reinforced rotary jet piles are arranged in a grid-like full house; The hole-reinforced rotary jetting pile is provided with a hole-reinforced rotary jetting pile on the outer side of the bored cast-in-place pile, and the hole-reinforced rotary jetting pile is located at the entrance and exit of the pipe jacking pipe section of the working well. 2 . The pipe jacking well according to claim 1 , wherein the thickness of the inner lining is 0.5 m to 0.8 m, and the thickness of the inner lining is 4 m to 6 m from top to bottom. Set up dark beams. 3 . The pipe jacking well according to claim 1 , which is suitable for use in desert anhydrous sand layer areas, is characterized in that, the thickness of the reinforced rotary jet pile at the bottom of the well is 2m to 6m, and the overlap range is 0.2m to 0.4m. 4 . The pipe jacking well according to claim 2 , wherein the width of the concealed beam is the same as the thickness of the inner lining, and the height of the concealed beam is 0.5m to 0.9m. 5 . 5. The pipe jacking working well suitable for the desert anhydrous sand layer area according to claim 1 is characterized in that, a first cushion layer is also provided at the joint between the inner lining and the crown beam, and the first cushion layer is 100mm thick ~200mm plain concrete cushion. 6. The pipe jacking well suitable for use in the desert anhydrous sand layer area according to claim 1, is characterized in that, a second cushion layer is also provided between the bottom plate and the bottom-hole reinforcement rotary jetting pile, and the second cushion layer is The thickness is 100mm-200mm, and the second cushion layer is used to support the bottom plate formwork.