Steel pipe pile supporting structure with pre-stressed anchor cables

Abstract

A steel pipe pile supporting structure with pre-stressed anchor cables comprises steel pipe piles, gravel mortar outside the piles, mortar inside the piles and a net hanging concrete layer. The steel pipe piles are arranged in the side wall of the foundation pit at intervals along the sideline of the foundation pit. Isolation frames are arranged on the steel pipe piles at intervals in the vertical direction; the isolation frame comprises a sleeve and an isolation rod; the sleeve sleeves the steel pipe pile; the isolation rods are connected to the sleeve at intervals in the circumferential direction. A steel strand is arranged between every two adjacent isolation rods; the lower end of the steel strand is anchored in gravel mortar outside the pile, and the upper end of the steel strand is anchored on an anchorage device at the top of the steel pipe pile; the net hanging concrete layer comprises a reinforcing mesh and a concrete layer; waist beams are arranged between the group of steel pipe piles in the vertical direction at intervals. Pre-stressed anchor cables are arranged on the waist beams; and the pre-stressed anchor cables are obliquely buried in a soil body around the foundation pit. The steel pipe pile supporting structure solves the technical problems that in order to achieve a good water retaining effect, a traditional steel pipe pile supporting structure provided with a pre-stressed anchor cable needs to adopt additional waterproof measures, so that construction cost is increased, and the construction period is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of building engineering construction, especially a steel pipe pile support structure with prestressed anchor cable. BACKGROUND

[0002] The site is divided into five engineering geological layers; according to the drilling conditions, the layers buried in the site are described as follows from top to bottom: ① layer, plain fill: miscellaneous color, loose, slightly wet-saturated, mainly composed of cohesive soil, sand, bricks, gravel, and a small amount of household garbage, newly accumulated, undercompacted, and uneven in soil quality. ② layer, silty clay: gray, white, and gray-brown, plastic, and soft plastic in some sections due to long-term soaking, mainly composed of clay and fine sand, with general toughness, no shaking response, medium dry strength, uneven soil quality, easy to soften after long-term immersion, and interlayer contains gravel and sand, and some sections contain boulders. According to regional experience and the results of this survey, the bearing capacity characteristic value f ak = 130 kPa. ③ layer, gravelly cohesive soil: gray-brown and gray-yellow, plastic-hard, granite weathering residual soil, mainly composed of clay and coarse gravel sand, with general toughness, no shaking response, medium dry strength, uneven soil quality, strong sand feeling when kneaded by hand, easy to disintegrate and soften after long-term immersion, and interlayer contains more sand particles and weathered debris, and some sections contain boulders. According to regional experience and the results of this survey, the bearing capacity characteristic value f ak = 170 kPa. ④ layer, strongly weathered granite: gray and gray-brown, medium-fine grained structure, blocky structure, main rock-forming minerals are quartz, feldspar, and mica, etc., the rock is strongly weathered, with extremely developed joints and fractures, the rock mass is broken, and the core is soil-included debris and debris. According to regional experience and the results of this survey, the bearing capacity characteristic value f ak = 300 kPa. ⑤ layer, moderately weathered granite: gray and gray-white, medium-fine grained structure, blocky structure, main rock-forming minerals are quartz, feldspar, and mica, etc., the rock mass is relatively complete, with slightly developed joints and fractures, the rock quality is hard-hard, the core is columnar, RQD = 50-80, and some sections contain strongly weathered debris. The stratum bearing capacity characteristic value f ak = 3000 kPa. In the drilling depth range, the groundwater is mainly pore-fracture phreatic water distributed in the ② silty clay, ③ gravelly cohesive soil, ④ strongly weathered granite, and ⑤ moderately weathered granite layers, the rock layer has weak water permeability, and the groundwater has little effect on the excavation of the foundation pit, therefore, no waterproof curtain is arranged around the foundation pit, and pipe well dewatering and water collection and drainage measures are adopted to assist construction.

[0003] Since the water stop curtain is not set around the foundation pit, the foundation pit support needs to have a certain water retaining function when designing the foundation pit support. The traditional steel pipe pile support structure with prestressed anchor cable is usually composed of the following parts: steel pipe pile: the steel pipe pile is the main part of the support structure, which is usually a tubular structure made of steel. The steel pipe pile bears the horizontal and vertical load of the soil and transmits it to the deep foundation, playing a supporting and stabilizing role. Pile foundation: the pile foundation is the bottom part of the steel pipe pile, which is usually fixed in the foundation by piling or bored pile, etc. The pile foundation can provide sufficient bearing capacity so that the steel pipe pile can stably bear the load of the soil. Connecting piece: the connecting piece is used to connect the steel pipe pile with other support structure components, such as beams, supports, etc. The connecting piece is usually welded or bolted to ensure the stability and integrity of the structure. Beam: the beam is located between the steel pipe piles and plays a connecting and supporting role. The beam can be made of steel, concrete, etc. to share the load of the soil and make the entire support structure form a stable whole. Support: the support is usually located above the beam to support and fix other structural components, such as retaining walls, revetments, etc. The support can be in different forms and materials according to the specific situation, such as steel support, concrete support, etc. These components together constitute the traditional steel pipe pile support structure with prestressed anchor cable, which is used to support and stabilize the soil in geotechnical engineering.

[0004] From the above structure, the traditional steel pipe pile support structure with prestressed anchor cable is usually not specially designed for water retaining, but mainly for soil support and stabilization. To achieve better water retaining effect, additional waterproof measures need to be taken, which will increase the construction cost and period. Practical new content

[0005] The purpose of the present application is to provide a steel pipe pile support structure with prestressed anchor cable, which solves the technical problem that the traditional steel pipe pile support structure with prestressed anchor cable needs to achieve better water retaining effect by taking additional waterproof measures, which increases the construction cost and period.

[0006] To achieve the above purpose, the present application adopts the following technical solutions.

[0007] The utility model provides a kind of steel pipe pile supporting structure with prestressed anchor cable, support on the side wall of the around of foundation pit, including steel pipe pile, pile outside gravel mortar poured in the periphery of steel pipe pile, pipe inside mortar poured in steel pipe pile and net concrete layer;The steel pipe pile has a group, interval is arranged in the side wall of foundation pit along the boundary of foundation pit;Crown beam is arranged on the top of a group of steel pipe pile lengthways;The steel pipe pile is vertically spaced apart and provided with spacer frame;The spacer frame includes sleeve and spacer rod;The sleeve is sleeved on the steel pipe pile, and is fixedly connected with the steel pipe pile;The spacer rod has a group, and is connected on the sleeve along the ring direction;Steel strand is arranged between adjacent spacer rods;The lower end of the steel strand is anchored in the pile outside gravel mortar, and the upper end of the steel strand is anchored on the anchor device on the top of steel pipe pile;The steel strand is prestressed steel strand;The net concrete layer includes steel mesh and concrete layer;The steel mesh is hung on the inner side of a group of steel pipe pile;The concrete layer is arranged between a group of steel pipe pile, and is wrapped on the steel mesh;Waist beam is vertically spaced apart and provided between a group of steel pipe pile;The prestressed anchor cable is inclinedly buried in the soil around foundation pit, and the upper end of the prestressed anchor cable is anchored on the waist beam.

[0008] Preferably, the spacing between vertically adjacent spacer frames is 1.3-1.7 m; The spacer rod is wavy, and is vertically connected to the sleeve.

[0009] Preferably, the lower end of the steel pipe pile is conical, and a guide cap is mounted on the lower end of the steel pipe pile.

[0010] Preferably, the steel strand includes an anchoring segment and a free segment; The anchoring segment is anchored in the pile outside gravel mortar; The outer side of the free segment is sleeved with a sleeve; The sleeve is poured in.

[0011] Preferably, the steel pipe pile is provided with two rows, and the spacing between the two rows of steel pipe piles is 500 mm; The waist beam is provided with a group, and is vertically spaced apart; A group of prestressed anchor cables is spaced apart on each waist beam.

[0012] Preferably, the lower part of the side wall of the foundation pit is sloped towards the foundation pit; The lower edge of the net concrete layer extends to the bottom of the slope surface; Anchor nails and drainage holes are spaced apart on the net concrete layer at the position of the slope surface; The anchor nails are buried in the slope body, and fix the net concrete layer with the slope body; The drainage holes are spaced apart in the horizontal direction, and a drainage pipe is mounted in the drainage hole; The drainage pipe is buried in the soil of the slope body, and the drainage pipe is inclinedly arranged; The lower end of the drainage pipe extends into the foundation pit, and the upper end of the drainage pipe is blocked with a fine stone filter bag; Drainage holes are spaced apart on the pipe wall of the drainage pipe.

[0013] Compared with the prior art, the utility model has the following characteristics and beneficial effects.

[0014] 1. The utility model discloses a steel pipe pile + anchor cable + slope + shotcrete support form is adopted according to the surrounding condition of site, can be cross from top to bottom, stratified and segmented when supporting structure construction, and construction personnel can arrange construction order reasonably, which avoids the influence of side slope stability.

[0015] 2. The utility model discloses the steel pipe pile's outside fills pile outer broken stone mortar, pours the mortar in the steel pipe pile inside, and simultaneously interval sets up the prestressed steel strand around the steel pipe pile, and the structure forms the whole prestressed steel pipe pile structure, and the design of the structure effectively improves the stress performance of steel pipe pile support structure.

[0016] 3. The utility model discloses the inside of a group of steel pipe piles is hung and set reinforced net, and the reinforced concrete layer is connected to each steel pipe pile by the reinforced net concrete layer, forms a whole, improves the overall rigidity and stability of support system. Meanwhile, the reinforced net concrete layer can effectively prevent groundwater from seeping into the soil body behind the support structure, plays good waterproof effect, prevents the soil from losing from the gap between the support structure, thereby maintaining the stability of soil body. In addition, the reinforced net concrete layer and steel pipe pile are synchronous construction in the utility model, do not need to set waterproof measure again, reduce construction cost and construction period. BRIEF DESCRIPTION OF DRAWINGS

[0017] The utility model will be further explained in detail in combination with the drawings.

[0018] Figure 1 It is the schematic diagram of steel pipe pile support structure with prestressed anchor cable when the steel pipe pile of the utility model is provided with two rows.

[0019] Figure 2 It is the schematic diagram of steel pipe pile support structure with prestressed anchor cable when the lower part of the side wall of foundation pit is graded to the inside of foundation pit in the utility model.

[0020] Figure 3 It is the structural schematic diagram of the soil body of slope body is buried drainage pipe in the utility model.

[0021] Figure 4 It is the structural schematic diagram of the steel pipe pile in the utility model.

[0022] Figure 5 It is the horizontal section structure schematic diagram of the isolation frame in the utility model.

[0023] Figure 6 It is the vertical section structure schematic diagram of the isolation frame in the utility model.

[0024] Figure 7 It is the horizontal section structure schematic diagram of the steel pipe pile in the utility model.

[0025] Figure 8It is the structure schematic view of the guide cap in the utility model.

[0026] Figure 9 It is the structure schematic view of the steel strand in the utility model.

[0027] Figure 10 It is the structure schematic view of the drainage ditch setting the water collecting well in the utility model.

[0028] Reference signs: 1 - foundation pit, 2 - steel pipe pile, 3 - pile outside gravel mortar, 4 - pipe inside mortar, 5 - netted concrete layer, 5.1 - steel mesh, 5.2 - concrete layer, 6 - crown beam, 7 - isolation frame, 7.1 - sleeve, 7.2 - isolation rod, 8 - steel strand, 8.1 - anchoring section, 8.2 - free section, 9 - anchorage device, 10 - waist beam, 11 - prestressed anchor cable, 12 - sleeve pipe, 13 - guide cap, 13.1 - pipe section, 13.2 - sharp head, 14 - anchoring nail, 15 - water outlet hole, 16 - water outlet pipe, 17 - fine stone filter bag, 18 - water retaining wall, 19 - drainage pipe, 20 - safety fence, 21 - drainage ditch, 22 - water collecting well, 23 - anchor plate. DETAILED DESCRIPTION

[0029] The steel pipe pile supporting structure with prestressed anchor cable is supported on the peripheral sidewall of the foundation pit 1, which comprises the steel pipe pile 2, the pile outside gravel mortar 3 filled around the steel pipe pile 2, the pipe inside mortar 4 filled in the steel pipe pile 2 and the netted concrete layer 5; the steel pipe pile 2 is a group, which is arranged in the sidewall of the foundation pit 1 along the boundary line of the foundation pit 1 at intervals; the crown beam 6 is arranged on the top of the group of steel pipe piles 2; characterized in that: the isolation frame 7 is arranged on the steel pipe pile 2 at intervals along the vertical direction; the isolation frame 7 comprises the sleeve 7.1 and the isolation rod 7.2; the sleeve 7.1 is sleeved on the steel pipe pile 2 and is fixedly connected with the steel pipe pile 2; the isolation rod 7.2 is a group, which is connected on the sleeve 7.1 at intervals along the circumferential direction; the steel strand 8 is arranged at the position between the adjacent isolation rods 7.2; the lower end of the steel strand 8 is anchored in the pile outside gravel mortar 3, and the upper end of the steel strand 8 is anchored on the anchorage device 9 on the top of the steel pipe pile 2; the steel strand 8 is the prestressed steel strand; the netted concrete layer 5 comprises the steel mesh 5.1 and the concrete layer 5.2; the steel mesh 5.1 is hung on the inner side of the group of steel pipe piles 2; the concrete layer 5.2 is arranged on the inner side between the group of steel pipe piles 2 and is wrapped on the steel mesh 5.1; the waist beam 10 is arranged at intervals along the vertical direction between the group of steel pipe piles 2; the prestressed anchor cable 11 is arranged on the waist beam 10 at intervals along the long axis of the waist beam 10; the prestressed anchor cable 11 is obliquely buried in the soil body around the foundation pit 1, and the upper end of the prestressed anchor cable 11 is anchored on the waist beam 10; the end of the prestressed anchor cable 11 is fixed by the anchorage device; the anchorage device adopts the clamping piece type anchorage device.

[0030] In this embodiment, the spacing between vertically adjacent isolation frames 7 is 1.3 to 1.7 m; the isolation rod 7.2 is wavy and is vertically connected to the sleeve 7.1.

[0031] In this embodiment, the lower end of the steel pipe pile 2 is conical, and a guide cap 13 is installed at the lower end of the steel pipe pile 2.

[0032] In this embodiment, the steel strand 8 includes an anchoring section 8.1 and a free section 8.2; the anchoring section 8.1 is anchored in the crushed stone mortar 3 outside the pile; a sleeve 12 is sleeved on the outside of the free section 8.2; the sleeve 12 is cast in the middle.

[0033] In this embodiment, the steel pipe piles 2 are arranged in double rows, with a spacing of 500mm between the two rows of steel pipe piles 2; the waist beams 10 are arranged in a set and are arranged at intervals along the vertical direction; a set of prestressed anchor cables 11 are arranged at intervals on each waist beam 10.

[0034] In this embodiment, the lower part of the sidewall of the foundation pit 1 slopes into the foundation pit 1; the lower edge of the wire mesh concrete layer 5 extends to the bottom of the slope; anchor nails 14 and drainage holes 15 are arranged at intervals on the wire mesh concrete layer 5 at the slope position; the anchor nails 14 are embedded in the slope body and fix the wire mesh concrete layer 5 to the slope body; the drainage holes 15 are arranged at intervals in the horizontal direction, and drainage pipes 16 are installed in the drainage holes 15; the drainage pipes 16 are buried in the soil of the slope body and are inclined; the lower end of the drainage pipe 16 extends into the foundation pit, and the upper end of the drainage pipe 16 is sealed with a fine stone filter bag 17; drainage holes 15 are spaced apart on the pipe wall of the drainage pipe 16.

[0035] In this embodiment, the interval between adjacent steel pipe piles 2 is 800mm, and the length of the steel pipe pile 2 is 10m.

[0036] In this embodiment, a retaining wall 18 is provided along the top of the capping beam 6 and the edge of the foundation pit; a drainage pipe 19 is installed on the outside of the retaining wall 18; a safety railing 20 is provided on the top of the capping beam 6 and inside the retaining wall; a drainage ditch 21 is provided along the bottom of the foundation pit 1 near the bottom edge; the slope of the bottom of the drainage ditch 21 is 0.2%.

[0037] ~0.5%; water collection wells 22 are set at intervals at drainage ditch 21.

[0038] In this embodiment, the length of the sleeve 7.1 is 100mm.

[0039] In the embodiment, the guide cap 13 comprises a pipe segment 13.1 and a pointed head 13.2; the pipe segment 13.1 is sleeved on the lower end of the steel pipe pile 2; the pointed head 13.2 is conically arranged at the bottom of the pipe segment 13.1; the length of the pipe segment 13.1 is 120 mm, and the length of the pointed head 13.2 is 70 mm.

[0040] In the embodiment, the fine stone filter bag 17 is composed of a filter cloth and gravel, and the filter cloth is wrapped outside the gravel. In the embodiment, an anchor plate 23 is installed on the steel pipe pile 2 near the top position; the anchor device 9 of the steel strand 8 is a clamping piece type anchor device, and the anchor device 9 is installed in the anchor plate 23.

[0041] The construction of the steel pipe pile is as follows.

[0042] (1) φ165x4.0 electric welded steel pipe is selected, the steel pipe pile is implanted by a drilling machine, the formed hole diameter is not less than 200 mm, and the formed hole depth is the design pile bottom elevation; when the steel pipe pile is difficult to implant, a heavy hammer is used to hammer to the design depth; the steel pipe is Q235B steel.

[0043] (2) The steel pipe is provided with a set of symmetrical slurry outlet holes every 0.5 m from the pile bottom, and no slurry outlet hole is provided within a 3 m long range from the pile top, the upper and lower positions of the slurry outlet holes are staggered, and the hole size is about 8 mm.

[0044] (3) The connection of the steel pipe of the grouting steel pipe pile adopts sleeve welding, the sleeve length is greater than twice the pile diameter, and the welding strength and quality should meet the current national standard.

[0045] (4) Ordinary Portland cement 42.5 grade is used for grouting, the water-cement ratio is 0.5, and the grouting pressure is 1.5 MPa.

[0046] (5) The strength of the cement slurry filled with gravel (particle size ≤40 mm) to form a consolidated body reaches 15 MPa.

[0047] (6) The construction sequence is: measurement and line laying → steel pipe manufacturing → hole forming by a drilling machine → hole cleaning → steel pipe installation → cleaning the inside of the steel pipe with water → installing a grouting pipe → injecting cement slurry → slurry overflow at the steel pipe opening → sealing the steel pipe opening → intermittent grouting for multiple times → slurry overflow around the steel pipe → removing the grouting pipe → filling gravel → completion.

[0048] (7) The cement slurry should be uniformly stirred, a storage tank should be arranged between the stirring tank and the grouting pump, and the slurry should be stirred before grouting to prevent segregation.

[0049] (8) The distance between the grouting pump and the hole opening is ≤30 m.

[0050] (9) The time interval between hole forming and cement slurry pouring should be as short as possible.

[0051] The construction of the steel pipe pile is as follows.

[0052] (1) The concrete strength grade of the pile top cap beam is C30 (ordinary). During construction, the laitance, low-strength concrete and broken parts at the top of the pile should be removed.

[0053] (2) The joints of the reinforcing bars should be staggered and located in areas of lower stress. The number of joints in the same cross section should not exceed 50% of the total number of main bars. All intersections of reinforcing bars and stirrups should be tied.

[0054] (3) The length of the pile body anchored into the crown beam shall not be less than 300mm.

[0055] The above embodiments are not exhaustive examples of specific implementation methods, and other embodiments may also exist. The purpose of the above embodiments is to illustrate the present utility model, rather than to limit the protection scope of the present utility model. All applications derived from simple variations of the present utility model fall within the protection scope of the present utility model.

Claims

1. A steel pipe pile supporting structure provided with prestressed anchor cables, which is supported on the peripheral sidewall of a foundation pit (1) and comprises steel pipe piles (2), pile outer gravel mortar (3) poured around the steel pipe piles (2), in-pipe mortar (4) poured in the steel pipe piles (2), and a layer of net-reinforced concrete (5); the steel pipe piles (2) are arranged in the sidewall of the foundation pit (1) in a group along the boundary line of the foundation pit (1) at intervals; a corbel (6) is arranged on the top of the steel pipe piles (2) in the group; characterized in that: The steel pipe pile (2) is vertically and spacedly provided with isolation frames (7); the isolation frame (7) comprises a sleeve (7.1) and an isolation rod (7.2); the sleeve (7.1) is sleeved on the steel pipe pile (2) and is fixedly connected with the steel pipe pile (2); the isolation rod (7.2) is one group and is connected on the sleeve (7.1) in a ring direction; a steel strand (8) is arranged at a position between adjacent isolation rods (7.2); a lower end of the steel strand (8) is anchored in the pile outside gravel mortar (3), and an upper end of the steel strand (8) is anchored on an anchor (9) at a top of the steel pipe pile (2); the steel strand (8) is a prestressed steel strand; the net hanging concrete layer (5) comprises a steel mesh (5.1) and a concrete layer (5.2); the steel mesh (5.1) is hung between a group of steel pipe piles (2); the concrete layer (5.2) is arranged on an inner side of the group of steel pipe piles (2) and is wrapped on the steel mesh (5.1); a waist beam (10) is vertically and spacedly arranged between the group of steel pipe piles (2); the waist beam (10) is vertically and spacedly provided with a prestressed anchor cable (11) along a long axis of the waist beam (10); the prestressed anchor cable (11) is obliquely buried in a soil body around the foundation pit (1), and an upper end of the prestressed anchor cable (11) is anchored on the waist beam (10).

2. The steel pipe pile supporting structure provided with a pre-stressed anchor cable according to claim 1, characterized in that: A spacing between vertically adjacent isolation frames (7) is 1.3-1.7 m; the isolation rod (7.2) is in a wave shape and is vertically connected on the sleeve (7.1).

3. The steel pipe pile supporting structure provided with a pre-stressed anchor cable according to claim 1, characterized in that: A lower end of the steel pipe pile (2) is in a conical shape, and a guide cap (13) is installed at the lower end of the steel pipe pile (2).

4. The steel pipe pile supporting structure provided with a pre-stressed anchor cable according to claim 1, characterized in that: The steel strand (8) comprises an anchoring section (8.1) and a free section (8.2); the anchoring section (8.1) is anchored in the pile outside gravel mortar (3); a sleeve (12) is sleeved on an outer side of the free section (8.2); the sleeve (12) is poured in.

5. The steel pipe pile supporting structure provided with a pre-stressed anchor cable according to claim 1, characterized in that: The steel pipe pile (2) is provided with double rows, and a spacing between the two rows of steel pipe piles (2) is 500 mm; the waist beam (10) is provided with one group and is vertically and spacedly arranged; one group of prestressed anchor cables (11) is spacedly arranged on each waist beam (10).

6. The steel pipe pile supported structure with prestressed anchor cables according to claim 1, characterized in that: A lower part of a side wall of the foundation pit (1) is graded into the foundation pit (1); a lower edge of the net hanging concrete layer (5) extends to a bottom of a slope surface; anchor nails (14) and drainage holes (15) are spacedly arranged on the net hanging concrete layer (5) at the slope surface position; the anchor nail (14) is buried in a slope body and fixes the net hanging concrete layer (5) and the slope body; the drainage holes (15) are horizontally and spacedly arranged, and a drainage pipe (16) is installed in the drainage hole (15); the drainage pipe (16) is buried in a soil body of the slope body and is obliquely arranged; a lower end of the drainage pipe (16) extends into the foundation pit, and a fine stone filter bag (17) is sealed at an upper end of the drainage pipe (16); drainage holes (15) are spacedly arranged on a pipe wall of the drainage pipe (16).

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