CN103967021B - A kind of prestressing force support system for elongated rectangular shape foundation ditch - Google Patents

Abstract

The invention discloses a prestressed support system for a long rectangular foundation pit. Angle braces are arranged at the apex of the foundation pit, and a group of fish-belly beam devices are arranged at the short side of the foundation pit. Partly set two or more fish-belly beam devices, and set up opposite braces between the two long sides at the position between two adjacent fish-belly beam devices to jointly support the foundation pit. Angle braces and opposite braces generate prestress by adjusting jacks, and the fish-belly beam device generates prestress by adjusting the tightness of steel strands. This kind of supporting structure occupies a small space as a whole, which is convenient for the excavation of the foundation pit and improves the efficiency. The reuse rate is high, and the cost of foundation pit support is reduced as a whole.

Description

A Prestressed Support System for Long Rectangular Foundation Pit

technical field

The invention belongs to the field of civil engineering, and in particular relates to a prestressed support structure for foundation pits.

Background technique

Most of the existing foundation pit support methods adopt the method of setting reinforced concrete purlins around the foundation pit, and then arranging mesh steel pipe supports on the inner periphery of the purlins. It takes up a lot of space, which is not conducive to the excavation of the earthwork in the foundation pit, and it cannot well apply prestress to the side wall of the foundation pit, and the support strength is low. Usually, the support force can only be increased by increasing the density of the steel pipe arrangement; and when different foundation pits are supported Steel pipes of different sizes need to be used, and the reuse rate of steel pipes is low, resulting in high costs for foundation pit support.

Contents of the invention

The technical problem to be solved by the present invention is to provide a foundation pit prestressed support structure that is easy to install and dismantle, takes up little space in the foundation pit, has high support strength and a high recovery rate of support profiles in view of the deficiencies in the prior art .

In order to realize the purpose of the present invention, the following technical schemes are adopted to achieve: a prestressed support system for a long rectangular foundation pit, including cement mixing piles driven downward along the outer periphery of the foundation pit, and the upper part of the cement mixing pile is poured The roof beam of the reinforced concrete structure is connected with the surrounding purlin profiled steel on the inner periphery of the roofing beam, and the surrounding purlin profile steel is fixedly connected with the roofing beam through the steel bar connector.

The purlin-shaped steel is H-shaped steel, and the flanges on both sides are equidistantly provided with connecting hole groups, each connecting hole group is composed of two connecting hole units, and each connecting hole unit has six connecting holes, six The connecting holes are distributed in two rows and three columns along the length direction of the purlin steel, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the longitudinal direction is 2a; The two ends of the section steel are fixedly welded with connecting plates, and there are four connecting holes distributed in two rows and two columns on the connecting plate, and the distance between the two adjacent connecting holes in the horizontal and vertical directions is 2a; The purlin steel is coaxially connected by four sets of bolts through the connecting plate.

The steel bar connector includes an L-shaped steel bar, the short side of the L-shaped steel bar is welded and fixed to the steel bar in the top beam, and the end of the long side of the L-shaped steel bar is coaxially welded with a steel bar that can be connected with an internal thread. The screw passing through the purlin-shaped steel is connected with the steel bar connector to fix the purlin-shaped steel and the roof beam; the short side of the L-shaped steel bar is welded to the steel bar in the roof beam and consolidated in the concrete of the roof beam, with high connection strength Not easy to come out.

The purlin-shaped steel located on both sides of the apex of the foundation pit is connected by two triangular connectors, one of which is connected between the connecting plates at the ends of the two purlin-shaped steel ends, and the other triangular connector is connected between the two Between the sides of the purlin-shaped steel close to the end; the two triangular connectors cooperate to make the two purlin-shaped steel at the corner position firmly connected and not easy to loosen or deform.

The triangular connecting piece includes two vertically welded connecting arms, six connecting holes are opened on each connecting arm, and an isosceles right triangle reinforcing plate is vertically welded between the two connecting arms.

There are 3 sets of angle braces near each vertex of the foundation pit, including 2 sets of single angle braces and 1 set of three angle braces.

The single-strand angle brace includes two first angle braces and a strut, the first angle brace is connected to the purlin profile steel by bolts, and the strut and the purlin profile steel on both sides of the apex of the foundation pit form an isosceles A right-angled triangle, one end of the strut is connected with a first angle brace through bolts, and a jack is connected between the other end of the brace and the other first angle brace.

Two channel steels are connected between the two single angle bracing struts, the two channel steels are perpendicular to each other, and an angle of 45 degrees is formed between the channel steels and the struts.

The first gusset seat is surrounded by three steel plates welded end to end to form an isosceles right triangle, a reinforcing plate is vertically welded in the middle of the three steel plates, six connecting holes are opened on the steel plate on the hypotenuse, and the six connecting The holes are distributed in two rows and three columns along the length direction of the hypotenuse, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; four connecting holes are opened on a steel plate located at a right angle side; The connecting holes are distributed in two rows and two columns, and the distance between two adjacent connecting holes in the horizontal and vertical directions is 2a; and the positions of the six connecting holes on the steel plate on the hypotenuse are biased towards the side of the steel plate without connecting holes; as shown in the figure As shown in 9, after the first angle brace is connected to the strut and the prestress is generated by the jack, the pressure is mainly concentrated on the steel plate on the right-angled side with the connection hole and the right part of the steel plate on the hypotenuse, so the It is most reasonable to set the connection holes of the steel plate on the right side. On the one hand, there is no need for too many connection holes, and on the other hand, the connection strength is guaranteed.

The three-strand angle brace includes two multi-strand angle braces and three struts; the multi-strand angle braces are connected between two adjacent purlin-shaped steels through bolts, and the multi-strand angle braces pass through The steel bar connector is connected to the top beam; each multi-strand angle brace is supported by a crossbeam, and the crossbeam is connected between two cement mixing piles, and the crossbeam and the purlin-shaped steel are arranged in parallel; the crossbeam and the purlin-shaped steel Parallel, this reduces the obstruction to the excavator when the foundation pit is excavated, which is conducive to improving efficiency.

The upper side wall of the cement mixing pile is connected with a bracket, and the bracket is connected with the H-shaped steel in the cement mixing pile through bolts; the crossbeam is erected on the bracket, and the crossbeam and the bracket are connected by bolts ;

4 connecting cover plates are evenly connected between the three struts, and the connecting cover plates and the struts are perpendicular to each other; 3 channel steels are also connected between the three struts, and each channel steel is at two Between two adjacent connection covers.

The multi-strand angle bracket is the second angle bracket or the third angle bracket.

The third angle brace is composed of three sections of H-shaped steel welded sequentially, the webs of the three sections of H-shaped steel are located on the same plane, and the three sections of H-shaped steel form an isosceles right-angled triangle; the two ends of the H-shaped steel e located on the hypotenuse It extends outward, and the end is fixedly welded with a connecting plate, and the end of an H-shaped steel f located at a right-angled side is also connected with a connecting plate; the outer flange of each H-shaped steel of the third angle bracket is provided with a connecting hole; the H-shaped steel There are six connecting hole units on the f flange, each connecting hole unit has four connecting holes, and the distance between the horizontal and vertical connecting holes in each connecting hole unit is 2a; There are five connecting hole units on the g-flange of the H-shaped steel; seven connecting hole units are opened on the middle section of the e-flange of the H-shaped steel; , the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; there are also multiple reinforcement ribs welded between the web and flange of each H-shaped steel, and the reinforcement ribs are located at each connection The horizontal center position of the hole unit; there is a reinforced H-shaped steel a parallel to H-shaped steel g welded between H-shaped steel f and H-shaped steel e, and two reinforced H-shaped steels are welded between reinforced H-shaped steel a, H-shaped steel e, and H-shaped steel g b; the webs of reinforced H-shaped steel a and reinforced H-shaped steel b are on the same plane as the web of H-shaped steel e, reinforced H-shaped steel a and reinforced H-shaped steel b are arranged vertically, and the reinforced H-shaped steel b is correspondingly reinforced between the two flanges of reinforced H-shaped steel a The position of the flange is welded with reinforcing ribs; between the adjacent H-shaped steels of the third angle bracket, as well as the joints between reinforced H-shaped steel a and H-shaped steel f, and the joints between reinforced H-shaped steel b and H-shaped steel g are welded with web The triangular reinforced steel plate on the same plane as the plate; the third angle brace has firm structure and high mechanical strength, and because the reinforced H-shaped steel a and the reinforced H-shaped steel b in the form of a cross are arranged, the H-shaped steel on each side can withstand large pressure.

More than two fish-belly beam devices are arranged on the long side of the foundation pit, and the fish-belly beam device includes 2 second corner braces, 5 web support between the two second corner braces, and A steel strand fixed between two second angle braces and prestressing each web support.

The second angle brace is composed of three sections of H-shaped steel welded sequentially, the webs of the three sections of H-shaped steel are located on the same plane, and the three sections of H-shaped steel form an isosceles right-angled triangle; the H-shaped steel i located on the hypotenuse faces outward There is an H-shaped steel h welded at the 1/3 position of the flange, and the two ends of H-shaped steel h and H-shaped steel i are welded and fixed with connecting plates; H-shaped steel i is located on the outer flange of H-shaped steel h and has two sets There are two rows and four rows of connecting holes, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; H-shaped steel i is located on the other side of H-shaped steel h facing outward, and a set of two rows Eleven columns and a set of two rows of six columns of connecting holes; multiple reinforcing ribs are welded between the web and flange inside the H-shaped steel i, and the reinforcing ribs are located at both ends of the H-shaped steel h, and adjacent two The position between the groups of connecting holes; the end of the H-shaped steel j located on the right-angled side is welded with a connecting plate, and the outward flange of the H-shaped steel j has six sets of connecting holes in two rows and two columns; the H-shaped steel located on the other right-angled side The end of k is vertically welded to the flange of H-shaped steel j close to the end, and the other end of H-shaped steel k is welded to the end of H-shaped steel i far away from H-shaped steel h; the outward flange of H-shaped steel k is provided with three sets of two rows and two columns The connection hole of H-shaped steel k near the end of H-shaped steel i is welded with a guide plate for steel strands to pass through, and the end of H-shaped steel i close to H-shaped steel k is welded with a steel strand fixing plate; H-shaped steel i, H-shaped steel A connecting steel plate is welded between j and H-shaped steel k, and two steel strand anchors are installed at the position of the connecting steel plate in the middle of the second angle bracket; the steel strand anchors apply tension to the steel strands, so that Each web support generates prestress on the cement mixing pile wall on the side wall of the foundation pit to ensure that the wall is stable and does not tilt or collapse. The ends of the steel strands pass through the guide plate and are divided into two strands, one strand is tightened by the anchorage, and the other strand is fixed on the steel strand fixing plate after the anchorage is tightened.

The web support includes a lower chord, a web vertically connected to the lower chord, an oblique strut connecting the web and the lower chord, an extension rod coaxially connected with the web to adjust the length of the web, and connecting The steel strand positioning head at the end of the extension rod; the ends of each lower string beam are connected in turn, and the lower string beam at the outermost end is connected to the end of the second angle bracket; the extension rod can adjust the effective length of the web as required , so that the steel strand has the required radian, that is, the angle between the steel strand and the web is appropriate.

The corbel brackets are also supported under each of the web bars, and the corbel brackets are fixedly welded to the H-shaped steel inserted in the cement mixing pile; the tension generated by the steel strands cooperating with the web bar supports is on the horizontal plane, Leg braces keep the ab brace from bouncing or loosening.

Among the five web supports, the web support located in the middle has the longest web and extension bars, and the web support located in the outermost has the shortest web bars and extension bars.

The steel strands are sequentially wound on the steel strand positioning heads at the ends of each web support, and the two ends of the steel strands pass through the guide plates on the second angle brackets and are fixed on the steel strand fixing plates and the steel strands. on the line anchor.

The steel strands form six left-right symmetrical parts between the two second angle braces and the five web supports, and from the middle to both sides are symmetrical line a, line b and line c, and line a An angle of 82 degrees is formed with the extension rod, an angle of 67 degrees is formed between line b and the extension rod, and an angle of 54 degrees is formed between line c and the extension rod; the steel strand matches the web support Setting it to the above-mentioned angle ensures sufficient prestress on the one hand, and on the other hand makes the web support occupy a smaller space as a whole, which is beneficial to the excavation of the excavator.

Below the two second angle braces and the five web supports, there are beams arranged parallel to the purlin-shaped steel, and the beams are connected to the cement mixing pile; the extension bars of the three web supports in the middle are also connected There is a reinforced beam; since the extension rods on both sides after the steel strand is erected to the steel strand positioning head will bend towards each other, the reinforced beam prevents the extension rod from being deformed and maintains a stable supporting force for a long time.

A fish-belly beam device is arranged on the short side of the foundation pit, and the fish-belly beam device includes 2 second corner braces, 3 web support between the two second corner braces, and fixed on the two Between the second angle braces and prestressed steel strands for each web support.

The steel strands form four left-right symmetrical parts between the two second angle braces and the three web brackets, and from the middle to both sides are symmetrical lines d and e, line d and the extension rod An included angle of 78 degrees is formed between them, and an included angle of 58 degrees is formed between the line e and the extension bar; since the length of the short side of the foundation pit is small, only 3 web supports are set and the steel strand is set to a larger angle to reduce the number of components and ensure the strength of the support.

Below the two second angle braces and the three web supports, there are crossbeams arranged parallel to the purlin-shaped steel, and the crossbeams are connected to the cement mixing piles.

Between the two long sides of the foundation pit, there is at least one set of supporting devices. The supporting devices are located between two adjacent groups of fish-belly beam devices. A set of struts between struts.

The eight-shaped brace includes two second angle braces, a triangle support and two sets of struts connecting the two second angle braces and the triangle support; the two second angle braces are connected by bolts It is connected between the purlin-shaped steel at the installation position, and the second angle brace is connected to the top beam through the steel connector; the two second angle braces are also the components of the two fish-belly beam devices on the left and right sides, The brace device makes the connection structure of the second angle brace at the end of the fish-belly beam device on both sides more stable, ensuring that the steel strand can exert a sufficient prestress.

The triangular support seat is an isosceles right-angled triangle, and each right-angled side of the triangular support seat is respectively connected with three struts, and the other end of the three struts is connected with a reinforced H-shaped steel, and the other side of the reinforced H-shaped steel corresponds to three braces There are three adjustable H-shaped steels connected to the position of the bar, and the other end of the adjusted H-shaped steel is connected to the H-shaped steel j on the right-angle side of the second angle bracket; three connecting cover plates are connected between the three braces of each group; the triangular support seat A strut perpendicular to the purlin-shaped steel is connected to the position of the right-angle vertex, and a jack is connected to the other end of the strut, and the jack is connected to the purlin-shaped steel between the two second angle braces.

The triangular support seats of the eight-shaped braces on both sides are connected by four struts; under the four struts, there are beams perpendicular to the struts, and the two ends of the beam are respectively connected to the upper part of the two cement mixing piles. There are scissors braces connected between them.

Compared with the prior art, the beneficial effect of the present invention is: by setting the corner braces at the apex of the foundation pit, a group of fish-belly beam devices are set at the short side of the foundation pit, and more than two girders are set at the long side of the foundation pit. fish-belly beam device, and a pair of braces is set between the two long sides between two adjacent fish-belly beam devices, which jointly play a role in supporting the foundation pit, and the corner braces and counter braces are generated by adjusting the jack Prestressing, the fish-belly beam device generates prestressing by adjusting the tightness of the steel strands. This kind of supporting structure occupies a small space as a whole, which is convenient for the excavation of the foundation pit and improves the efficiency. The reuse rate is high, and the cost of foundation pit support is reduced as a whole.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the present invention.

Figure 2 is a schematic diagram of the connection structure between the purlin shaped steel and the top beam.

Fig. 3 is a structural schematic diagram of a steel bar connector.

Fig. 4 is a schematic diagram of the connection structure between the triangular connector and the purlin-shaped steel.

Fig. 5 is a schematic structural diagram of a triangular connector.

FIG. 6 is a schematic view of the structure viewed from the bottom of FIG. 5 .

Fig. 7 is a schematic diagram of the angle brace structure at a vertex of the foundation pit.

Fig. 8 is a structural schematic diagram of a single angle brace.

Fig. 9 is a schematic structural view of the first angle brace.

FIG. 10 is a schematic structural view of FIG. 9 in a plan view direction.

Fig. 11 is a schematic structural view of the third angle brace.

Fig. 12 is a schematic diagram of the connection structure of the beam.

Fig. 13 is a schematic structural view of the fish-belly beam device arranged on the long side of the foundation pit.

Fig. 14 is a schematic structural view of the second angle brace.

Figure 15 is a schematic structural view of the web support.

Fig. 16 is a schematic diagram of the installation structure of the web support.

Fig. 17 is a structural schematic diagram of a fish-belly beam device arranged on the short side of the foundation pit.

Fig. 18 is a schematic structural view of the supporting device arranged between the two long sides of the foundation pit.

Fig. 19 is a schematic diagram of the structure of the eight-character brace.

Fig. 20 is a schematic diagram of the installation structure of the lower beam of the supporting device.

Detailed ways

A detailed description will be given below of specific embodiments of the present invention according to the accompanying drawings.

As shown in Figures 1 to 20, a prestressed support system for a long rectangular foundation pit described in this embodiment includes a cement mixing pile 40 driven downward along the outer periphery of the foundation pit, and the cement mixing pile The upper part is poured with a reinforced concrete structure top beam, and the inner periphery of the top beam is connected with a purlin profile steel 10, and the purlin profile steel is fixedly connected with the top pressure beam through a steel bar connector 70.

The purlin-shaped steel is H-shaped steel, and the flanges on both sides are equidistantly provided with connecting hole groups, each connecting hole group is composed of two connecting hole units, and each connecting hole unit has six connecting holes, six The connecting holes are distributed in two rows and three columns along the length direction of the purlin steel, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the longitudinal direction is 2a; The two ends of the section steel are fixedly welded with a connecting plate 01, and there are four connecting holes arranged in two rows and two columns on the connecting plate, and the distance between two adjacent connecting holes in the horizontal and vertical directions is 2a.

The steel bar connector includes an L-shaped steel bar 701, the short side of the L-shaped steel bar is welded and fixed to the steel bar in the top beam, and the end of the long side of the L-shaped steel bar is coaxially welded with a steel bar with an internal thread that can be connected to a screw The connector 702 is connected with the steel bar connector through the screw 703 passing through the purlin profile steel so as to fix the purlin profile steel and the top beam.

The purlin-shaped steel on both sides of the apex of the foundation pit is connected by two triangular connectors 20, one of which is connected between the connecting plates at the ends of the two purlin-shaped steel ends, and the other triangular connector is connected between the two ends of the purlin-shaped steel. between the sides of the purlin-shaped steel next to the end.

The triangular connector includes two vertically welded connecting arms 202, each of which is provided with six connecting holes, and an isosceles right triangle reinforcement plate 201 is vertically welded between the two connecting arms.

There are 3 sets of angle braces near each vertex of the foundation pit, including 2 sets of single angle braces and 1 set of three angle braces.

The single-strand angle brace includes two first angle braces 21 and a strut 11, the first angle brace is connected to the purlin-shaped steel by bolts, and the brace and the purlin-shaped steel on both sides of the apex of the foundation pit form a In an isosceles right triangle, one end of the strut is connected to a first angle brace by bolts, and a jack 30 is connected between the other end of the brace and the other first angle brace.

Two channel steels 14 are connected between the braces of the two single angle braces, the two channel steels are perpendicular to each other, and an angle of 45 degrees is formed between the channel steels and the braces 11 .

The first gusset seat is surrounded by three steel plates welded end to end to form an isosceles right triangle, a reinforcing plate is vertically welded in the middle of the three steel plates, six connecting holes are opened on the steel plate on the hypotenuse, and the six connecting The holes are distributed in two rows and three columns along the length direction of the hypotenuse, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; four connecting holes are opened on a steel plate located at a right angle side; The connecting holes are distributed in two rows and two columns, and the distance between two adjacent connecting holes in the horizontal and vertical directions is 2a; and the positions of the six connecting holes on the steel plate on the hypotenuse are biased towards the side of the steel plate without connecting holes.

The three-strand angle brace includes two multi-strand angle braces and three struts; the multi-strand angle braces are connected between two adjacent purlin-shaped steels through bolts, and the multi-strand angle braces pass through The steel bar connector is connected with the top beam; each multi-strand angle brace supports a crossbeam 13, which is connected between two cement mixing piles 40, and the crossbeam is arranged in parallel with the purlin-shaped steel.

The upper side wall of the cement mixing pile is connected with a bracket, and the bracket is connected with the H-shaped steel in the cement mixing pile through bolts; the crossbeam is erected on the bracket, and the crossbeam and the bracket are connected by bolts .

4 connecting cover plates are evenly connected between the three struts, and the connecting cover plates and the struts are perpendicular to each other; 3 channel steels are also connected between the three struts, and each channel steel is at two Between two adjacent connection covers.

The multi-strand angle bracket is the second angle bracket 22 or the third angle bracket 23 .

The third angle brace is composed of three sections of H-shaped steel welded sequentially, the web plates of the three sections of H-shaped steel are located on the same plane, and the three sections of H-shaped steel form an isosceles right triangle; the two ends of the H-shaped steel e234 located on the hypotenuse It extends outward, and the end is fixedly welded with a connecting plate, and the end of an H-shaped steel f235 located on the right-angled side is also connected with a connecting plate; the outer flange of each H-shaped steel of the third angle bracket is provided with a connecting hole; the H-shaped steel There are six connecting hole units on the f flange, each connecting hole unit has four connecting holes, and the distance between the horizontal and vertical connecting holes in each connecting hole unit is 2a; There are five connecting hole units on the g236 flange of the H-shaped steel; seven connecting hole units are opened in the middle section of the e-flange of the H-shaped steel, and two sets of connecting holes in two rows and eight rows are opened on the two ends of the e-flange of the H-shaped steel , the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; there are also multiple reinforcement ribs welded between the web and flange of each H-shaped steel, and the reinforcement ribs are located at each connection The horizontal center position of the hole unit; there is a reinforced H-shaped steel a231 parallel to H-shaped steel g welded between H-shaped steel f and H-shaped steel e, and two reinforced H-shaped steels are welded between reinforced H-shaped steel a, H-shaped steel e, and H-shaped steel g b232; the webs of reinforced H-shaped steel a and reinforced H-shaped steel b are on the same plane as the web of H-shaped steel e, the reinforced H-shaped steel a and the reinforced H-shaped steel b are arranged vertically, and the reinforced H-shaped steel b is correspondingly reinforced between the two flanges of reinforced H-shaped steel a The position of the flange is welded with reinforcing ribs; between the adjacent H-shaped steels of the third angle bracket, as well as the joints between reinforced H-shaped steel a and H-shaped steel f, and the joints between reinforced H-shaped steel b and H-shaped steel g are welded with web The triangular reinforced steel plate 233 of the same plane.

More than two fish-belly beam devices are arranged on the long side of the foundation pit. The fish-belly beam device includes 2 second angle braces 22, and 5 web support 17 between the two second angle braces. , and steel strands 50 fixed between the two second angle braces and applying prestress to each web support.

The second angle brace is composed of three sections of H-shaped steel welded sequentially, the webs of the three sections of H-shaped steel are located on the same plane, and the three sections of H-shaped steel form an isosceles right triangle; the H-shaped steel i221 on the hypotenuse faces outward There is an H-shaped steel h222 welded at the 1/3 position of the flange, and the two ends of H-shaped steel h and H-shaped steel i are welded and fixed with connecting plates; There are two rows and four rows of connecting holes, the distance between two adjacent connecting holes in the horizontal direction is a, and the distance between two adjacent connecting holes in the vertical direction is 2a; H-shaped steel i is located on the other side of H-shaped steel h facing outward, and a set of two rows Eleven columns and a set of two rows of six columns of connecting holes; multiple reinforcing ribs are welded between the web and flange inside the H-shaped steel i, and the reinforcing ribs are located at both ends of the H-shaped steel h, and adjacent two The position between the groups of connecting holes; the end of the H-shaped steel j223 located on the right-angled side is welded with a connecting plate, and the outward flange of the H-shaped steel j has six sets of connecting holes in two rows and two rows; the H-shaped steel located on the other right-angled side The end of k224 is vertically welded with the flange of H-shaped steel j close to the end, and the other end of H-shaped steel k is welded with the end of H-shaped steel i far away from H-shaped steel h; the outward flange of H-shaped steel k is provided with three sets of two rows and two rows The connecting hole of the connecting hole; H-shaped steel k is welded with a guide plate 225 for steel strands passing through near the end of H-shaped steel i, and a steel strand fixing plate 226 is welded near the end of H-shaped steel i near H-shaped steel k; H-shaped steel i, A connecting steel plate 227 is welded between the H-shaped steel j and the H-shaped steel k, and two steel strand anchors 228 are installed at the middle part of the second angle bracket.

The web support 17 includes a lower chord 171, a web 173 vertically connected to the lower chord, an oblique strut 172 connecting the web and the lower chord, and an extension for adjusting the length of the web coaxially connected with the web. The rod 174, and the steel strand positioning head 175 connected to the end of the extension rod; the ends of each lower string beam are connected in turn, and the lower string beam at the outermost end is connected to the end of the second angle brace.

The corbel bracket 170 is also supported under each of the web bars, and the corbel bracket is fixedly welded to the H-shaped steel inserted in the cement mixing pile 40 .

Among the five web supports, the web support located in the middle has the longest web and extension bars, and the web support located in the outermost has the shortest web bars and extension bars.

The steel strands are sequentially wound on the steel strand positioning heads at the ends of each web support, and the two ends of the steel strands pass through the guide plates on the second angle brackets and are fixed on the steel strand fixing plates and the steel strands. on the line anchor.

The steel strands form six symmetrical parts between the two second angle brackets and the five web supports. From the middle to both sides, there are symmetrical lines a501, b502 and c503, and line a An angle of 82 degrees is formed with the extension rod, an angle of 67 degrees is formed between line b and the extension rod, and an angle of 54 degrees is formed between line c and the extension rod.

Below the two second angle braces and the five web supports, there are beams arranged parallel to the purlin-shaped steel, and the beams are connected to the cement mixing pile; the extension bars of the three web supports in the middle are also connected There are reinforced beams.

A fish-belly beam device is arranged on the short side of the foundation pit, and the fish-belly beam device includes 2 second corner braces, 3 web support between the two second corner braces, and fixed on the two Between the second angle braces and prestressed steel strands for each web support.

The steel strands form four left-right symmetrical parts between the two second angle braces and the three web brackets. From the middle to both sides, there are symmetrical line d504 and line e505, line d and the extension rod An angle of 78 degrees is formed between them, and an angle of 58 degrees is formed between the line e and the extension rod.

Below the two second angle braces and the three web supports, there are crossbeams arranged parallel to the purlin-shaped steel, and the crossbeams are connected to the cement mixing piles.

Between the two long sides of the foundation pit, there is at least one set of supporting devices. The supporting devices are located between two adjacent groups of fish-belly beam devices. A set of struts between struts.

The eight-shaped brace includes two second angle braces 22, a triangle support 24 and two groups of struts connecting the two second angle braces and the triangle brace; the two second angle braces The purlin-shaped steel at the installation position is connected by bolts, and the second angle brace is connected to the top beam by a steel bar connector.

The triangular support seat is an isosceles right-angled triangle, and each right-angled side of the triangular support seat is respectively connected with three struts, and the other ends of the three struts are connected with a reinforced H-shaped steel 15, and the other side of the reinforced H-shaped steel corresponds to three There are three adjustable H-shaped steel 16 connected to the position of the strut, and the other end of the adjusted H-shaped steel is connected with the H-shaped steel j223 on the right-angle side of the second angle bracket; three connecting cover plates 12 are connected between the three struts of each group; A strut perpendicular to the purlin-shaped steel is connected to the right-angle vertex of the triangular support seat, and the other end of the strut is connected to a jack 30, and the jack is connected to the purlin-shaped steel between the two second angle braces.

The triangular support seats of the eight-shaped braces on both sides are connected by four struts; under the four struts, there are beams perpendicular to the struts, and the two ends of the beam are respectively connected to the upper part of the two cement mixing piles. There are scissors braces 42 connected between them.

During the construction, the cement mixing pile wall is formed by the SMW construction method, and the top beam is poured, and then the purlin steel, angle brace, opposite brace device and fish-belly beam device are installed. Then the foundation pit can be excavated. After the foundation pit construction is completed, the parts of the supporting structure can be removed and sorted for reuse.

Claims (1)

1. the prestressing force support system for elongated rectangular shape foundation ditch, it is characterized in that: include the cement mixing pile squeezed into along foundation ditch periphery downwards, the capping beam of cement mixing pile top pouring reinforcement concrete structure, capping beam inner circumferential is connected with encloses purlin shaped steel, encloses purlin shaped steel and is fixedly connected with capping beam by rebar connector;

The described purlin shaped steel that encloses is H profile steel, the edge of a wing of its both sides equidistantly offers connecting hole group, each connecting hole group is made up of two connecting hole unit, each connecting hole unit has six connecting holes, six connecting holes are along enclosing purlin shaped steel length direction with the formal distribution of two row three row, distance between two laterally adjacent connecting holes is a, and the distance between two longitudinally adjacent connecting holes is 2a; The two ends of enclosing purlin shaped steel are fixedly welded with junction plate, and junction plate offers with four connecting holes of two row's two row formal distributions, the distance between two horizontal, longitudinally adjacent connecting holes is 2a;

Described rebar connector includes L shape reinforcing bar, reinforcement welding in the minor face of L shape reinforcing bar and capping beam is fixed, end, the long limit coaxial welding of L shape reinforcing bar has that tool is female can the reinforcing bar connector of attachment screw, to be connected thus will to enclose purlin shaped steel and capping beam is fixed through the screw enclosing purlin shaped steel with reinforcing bar connector;

Connected by two triangle connection elements enclosing between purlin shaped steel of foundation ditch vertex position both sides, one of them triangle connection element is connected between two junction plates enclosing purlin shaped steel end, and another triangle connection element is connected between two sides of enclosing the adjacent end of purlin shaped steel;

Described triangle connection element includes the linking arm of two vertical weldings, each linking arm offers six connecting holes, is vertically welded with the gusset plate of an isosceles right triangle between two linking arms;

At foundation ditch, each summit place is provided with 3 groups of angle braces, includes 2 groups of sub-thread angle braces and 1 group of three strands of angle brace;

Described sub-thread angle brace includes two the first angle brace seats and a strut, first angle brace seat is bolted and is enclosing on purlin shaped steel, strut and foundation ditch summit two gusset purlin shaped steel form an isosceles right triangle, one end of strut and a first angle brace seat are bolted, and are connected with a jack between the other end of strut and another the first angle brace seat;

Be connected with two channel-section steels between the strut of two sub-thread angle braces, two channel-section steels are mutually vertical, and between channel-section steel and strut shape is in angle of 45 degrees;

The first described angle brace seat surrounds an isosceles right triangle by three block plate head and the tail successively welding, three block plate intermediate vertical are welded with one piece of stiffener, the steel plate being positioned at hypotenuse offers six connecting holes, six connecting holes arrange three column distributions along hypotenuse length direction with two, laterally the distance of adjacent two connecting holes is a, and longitudinally the distance of adjacent two connecting holes is 2a; The steel plate being positioned at a right-angle side offers four connecting holes; Four connecting holes are with two row's two column distributions, and distance that is horizontal, longitudinally adjacent two connecting holes is 2a; And the position deflection being positioned at six connecting holes on the steel plate of hypotenuse does not offer the steel plate side of connecting hole;

Three strands of described angle braces include two multiply angle brace seats and three struts; Described multiply angle brace seat is bolted and adjacently encloses between purlin shaped steel at two, and multiply angle brace seat is connected with capping beam by rebar connector; Each multiply angle brace seat supported underneath has crossbeam, and described crossbeam is connected between two cement mixing piles, and crossbeam with enclose purlin shaped steel and be arranged in parallel;

Described cement mixing pile upper portion side wall is connected with bracket part, and bracket part is connected with the H profile steel in cement mixing pile by bolt; Described beam erection is on bracket part, and crossbeam and bracket part are bolted;

Evenly be connected with 4 between three described struts and connect cover plate, connect cover plate mutually vertical with strut; Also be connected with 3 channel-section steels between three described struts, each channel-section steel is between two adjacent connection cover plates;

Described multiply angle brace seat is the second angle brace seat or trivet seat;

Described trivet seat is welded successively by three sections of H profile steel and forms, and the web of three sections of H profile steel is in the same plane, and three sections of H profile steel surround an isosceles right triangle; The H profile steel e two ends being positioned at hypotenuse stretch out, and end winding support is welded with junction plate, and the H profile steel f end being positioned at right-angle side is also connected with a junction plate; The edge of a wing of described each H profile steel periphery of trivet seat offers connecting hole; The H profile steel f edge of a wing offers six connecting hole unit, each connecting hole unit has four connecting holes, and the distance in each connecting hole unit laterally, longitudinally between two connecting holes is 2a; The H profile steel g edge of a wing being positioned at another right-angle side offers five connecting hole unit; The interlude on the H profile steel e edge of a wing offers seven connecting hole unit, and the two end portions on the H profile steel e edge of a wing offers the connecting hole that two group two is arranged eight row, and laterally the distance of two adjacent connecting holes is a, and longitudinally the distance of two adjacent connecting holes is 2a; Also be welded with multiple reinforcing gusset between the web of each H profile steel and the edge of a wing, reinforce the center that gusset is positioned at each connecting hole unit transverse; Be welded with a reinforcing H profile steel a parallel with H profile steel g between H profile steel f with H profile steel e, reinforcing is welded with two sections and reinforces H profile steel b between H profile steel a and H profile steel e, H profile steel g; Reinforce H profile steel a, reinforce the web of H profile steel b and the web isoplanar of H profile steel e, reinforce H profile steel a and reinforce that H profile steel b is vertical to be arranged, and the position reinforcing the correspondence reinforcing H profile steel b edge of a wing between H profile steel a two edge of a wing is welded with reinforcing gusset; Between each adjacent H profile steel of trivet seat, and reinforce H profile steel a and H profile steel f junction, reinforce H profile steel b and H profile steel g junction is all welded with the isoplanar triangular reinforced steel plate with web;

The long limit of foundation ditch is provided with plural fish belly sill device, fish belly sill device includes 2 the second angle brace seats, 5 web member supports between two the second angle brace seats, and to be fixed between two the second angle brace seats and steel strand to each web member support Shi Hanzhang;

The second described angle brace seat is welded successively by three sections of H profile steel and forms, and the web of three sections of H profile steel is in the same plane, and three sections of H profile steel surround an isosceles right triangle; 1/3 position on the H profile steel i the being positioned at hypotenuse edge of a wing is outwardly welded with a H profile steel h, and the both ends of H profile steel h and H profile steel i are all welded with junction plate; H profile steel i is positioned at H profile steel h side and the edge of a wing offers the connecting hole that 2 group two is arranged four row outwardly, and laterally the distance of two adjacent connecting holes is a, and longitudinally the distance of two adjacent connecting holes is 2a; H profile steel i is positioned at H profile steel h opposite side and the edge of a wing offers one group two outwardly and arrange the connecting hole that 11 row and a group two arrange six row; Web inside H profile steel i and be welded with multiple reinforcing gusset between the edge of a wing, reinforces the position that gusset is positioned at H profile steel h two ends, and the position between two adjacent groups connecting hole; The H profile steel j welding edges being positioned at right-angle side has junction plate, and the H profile steel j edge of a wing outwardly offers the connecting hole that six group two is arranged two row; Be positioned at the edge of a wing vertical welding that the end of the H profile steel k of another right-angle side and H profile steel j are close to end, the other end of H profile steel k welds away from one end of H profile steel h with H profile steel i; The H profile steel k edge of a wing outwardly offers the connecting hole that three group two is arranged two row; H profile steel k is welded with a guide plate passed for steel strand near the end position of H profile steel i, and H profile steel i is welded with a steel strand fixed head near one end of H profile steel k; H profile steel i, be welded with a junction steel plate between H profile steel j and H profile steel k, the junction steel plate position be positioned in the middle part of the second angle brace seat is provided with two steel strand anchorages; Described steel strand end is divided into two strands through after guide plate, and one is strained by ground tackle, and another stock is fixed on steel strand fixed head after ground tackle tension;

Described web member support include lower-cord beam, with lower-cord beam web member connected vertically, the oblique fulcrum bar being connected web member and lower-cord beam, also comprise the extension rod of the adjustment web member length be coaxially connected with web member, and be connected to the steel strand positioning head of extension rod end; Each lower-cord beam end connects successively, and the lower-cord beam being positioned at outermost end is connected with the second angle brace seat end;

The below of each web member described is also supported with angle-table bracket, and angle-table bracket fixedly welds with the H profile steel be inserted in cement mixing pile;

In 5 described web member supports, be positioned at middle web member support and there is the longest web member and extension rod, be positioned at outermost web member support and there is the shortest web member and extension rod;

Described steel strand are successively around on the steel strand positioning head of each web member bracket end, and the two ends of steel strand are passed the guide plate on the second angle brace seat and are fixed on steel strand fixed head and steel strand anchorage;

Described steel strand form symmetrical six parts between two the second angle brace seats and 5 web member supports, symmetrical line a, line b and line c is followed successively by toward both sides from middle, the angle of 82 degree is formed between line a and extension rod, form the angle of 67 degree between line b and extension rod, between line c and extension rod, form the angle of 54 degree;

Two the second angle brace seats and 5 web member support supported underneath have and the crossbeam enclosing purlin shaped steel and be arranged in parallel, and described crossbeam is connected on cement mixing pile; Also reinforcement is connected with between the extension rod of three web member supports at middle part;

The minor face of foundation ditch is provided with a fish belly sill device, fish belly sill device includes 2 the second angle brace seats, 3 web member supports between two the second angle brace seats, and to be fixed between two the second angle brace seats and steel strand to each web member support Shi Hanzhang;

Described steel strand form symmetrical four parts between two the second angle brace seats and 3 web member supports, symmetrical line d and line e is followed successively by toward both sides from middle, form the angle of 78 degree between line d and extension rod, between line e and extension rod, form the angle of 58 degree;

Two the second angle brace seats and 3 web member support supported underneath have and the crossbeam enclosing purlin shaped steel and be arranged in parallel, and described crossbeam is connected on cement mixing pile;

At least one group is provided with to support arrangement between two long limits of foundation ditch, to support arrangement between two adjacent groups fish belly sill device, often group one group of strut that support arrangement is included the support of two Eight characters and is connected between two Eight characters supports;

Described Eight characters support includes two the second angle brace seats, a gusseted seat and connects two groups of struts of two the second angle brace seats and gusseted seat; Two described the second angle brace seats are bolted enclosing between purlin shaped steel in installation site, and the second angle brace seat is connected with capping beam by rebar connector;

Described gusseted seat is isosceles right triangle, each right-angle side of gusseted seat is connected to three struts, three strut other ends are connected with a reinforcement H profile steel, the position of corresponding three struts of reinforcement H profile steel opposite side is connected with three and regulates H profile steel, regulates the H profile steel other end to be connected with the H profile steel j of the second angle brace seat right-angle side; Be connected with three between three struts often organized and connect cover plate; Described gusseted seat right-angled apices position is connected with one perpendicular to the strut enclosing purlin shaped steel, and the strut other end connects a jack, and the purlin shaped steel that encloses between jack with two the second angle brace seats is connected;

Connected by four struts between the gusseted seat of both sides Eight characters support; Four strut supported underneath have the crossbeam vertical with strut, and crossbeam two ends are connected to two cement mixing pile tops, are connected with bridging between two cement mixing piles.