Foundation pit fringe truss combined steel supporting system and construction method thereof

Abstract

The foundation pit fringe truss combined steel supporting system is used for being installed in a foundation pit and comprises an outer side truss, an inner side truss, a combined profile steel angle brace, a combined profile steel diagonal brace, a main supporting steel structure and a fixed-point stress detecting and adjusting mechanism. Each fixed-point stress detection and adjustment mechanism comprises a pressure sensor, a top seat, a base, a pushing block, a screw, a fixing rod, a hexagonal threaded sleeve, a first locking piece, a second locking piece, an elastic anti-skid gasket and a follow-up force transmission mechanism. Through the arrangement of the fixed-point stress detection and adjustment mechanism, shear stress applied to the inner wall of the foundation pit can be monitored in real time, corresponding supporting force is applied to the outer side truss, deformation of the outer side truss can be prevented, the supporting force of the outer side truss can be improved, and deformation or collapse of the inner wall of the foundation pit can be prevented.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering, and in particular to a foundation pit side truss combined steel support system and a construction method thereof. Background Art

[0002] The general trend of urban underground space development is deep excavation and large space. At present, the foundation pit support is to set a circle of side trusses and steel support structures inside the foundation pit, and fix the steel support structure inside the side trusses so that the side trusses support the inner wall of the foundation pit. However, since the outer periphery of the upper side of the foundation pit is often subjected to a large load, when the load increases to a certain extent, the shear stress in a certain direction of a certain area inside the foundation pit increases, causing the inner wall of the foundation pit to squeeze the side trusses in a certain area, causing the side trusses to deform, which will not only affect the normal use of the side trusses next time, but also easily cause landslides in some areas of the foundation pit. Summary of the invention

[0003] The object of the present invention is to provide a foundation pit side truss combined steel support system and a construction method thereof, so as to solve the above-mentioned technical problems.

[0004] The technical solution adopted by the present invention is as follows:

[0005] A foundation pit side truss combined steel support system, used for installation in a foundation pit, comprises an outer truss, an inner truss, a combined steel angle brace, a combined steel brace, a main brace steel structure and a fixed-point stress detection and adjustment mechanism, wherein the outer truss and the inner truss are both arranged in a ring shape, the inner truss is arranged on the inner side of the outer truss, a plurality of the combined steel angle braces are arranged at the angle position on the inner side of the inner truss, the combined steel brace and the main brace steel structure are arranged at the middle part of the inner side of the inner truss, and a plurality of the fixed-point stress detection and adjustment mechanisms are arranged between the inner truss and the outer truss;

[0006] Each of the fixed-point stress detection and adjustment mechanisms includes a pressure sensor, a top seat, a base, a pushing block, a screw, a fixed rod, a hexagonal threaded sleeve, a first locking piece, a second locking piece, an elastic anti-slip pad and a follow-up force transmission mechanism, one end of the top seat is connected to the inner wall of the outer truss, the base is connected to the outer wall of the inner truss, one end of the screw is detachably connected to the other end of the top seat, one end of the fixed rod is connected to the base, the other end of the fixed rod is rotatably provided with the hexagonal threaded sleeve, the other end of the screw is movably arranged in the hexagonal threaded sleeve and the fixed rod, an installation groove is opened on the other end surface of the top seat, the pressure sensor is arranged in the installation groove, and the pressure sensor is arranged in the installation groove. The sensor is connected to the controller, the pushing block is provided on the outer edge of one end of the screw, the pushing block is in contact with the other end surface of the top seat and the pressure sensor, planes are provided on the outer walls on both sides of the screw, the elastic anti-slip gasket is fixed on the planes, the first locking piece is detachably provided on the hexagonal threaded sleeve, the second locking piece is detachably provided on the fixed rod, the first locking piece and the second locking piece can both be against the elastic anti-slip gasket, a plurality of follow-up force transmission mechanisms are provided on the periphery of the fixed rod, one end of each of the follow-up force transmission mechanisms is respectively hinged to the pushing block, and the other end of each of the follow-up force transmission mechanisms is respectively connected to the outer wall of the inner truss.

[0007] Preferably, each of the fixed-point stress detection and adjustment mechanisms also includes a fixing plate and a first bolt, a positioning hole and a limiting hole that are interconnected are opened in the middle of the top seat, the limiting hole is close to one end of the top seat, and the positioning hole is close to the other end of the top seat, one end of the screw rod is inserted into the positioning hole and extends into the limiting hole, the fixing plate is arranged in the limiting hole, and the fixing plate is connected to one end of the screw rod through the first bolt.

[0008] Preferably, an external thread is provided on the outer wall of the screw, and the plane is arranged along the axial direction of the screw and divides the external thread into two sections.

[0009] Preferably, a first connecting hole is provided on each side surface of the hexagonal threaded sleeve, and the first locking member can be arranged in any one of the first connecting holes.

[0010] Preferably, each of the follow-up force transmission mechanisms includes a fixed seat, a block, a spring, a transmission mechanism, a limit block and a force transmission rod. A slide groove is arranged inside the base, and a plurality of positioning grooves are opened on the inner walls on both sides of the slide groove. A limit block is rotatably arranged in each of the positioning grooves, one end of the spring is connected to one side of the limit block, and the other end of the spring is connected to the inner wall of the positioning groove. The transmission mechanism is arranged on the fixed seat, and the transmission mechanism is connected to the plurality of limit blocks for controlling the limit block to rotate into the positioning groove. One end of the force transmission rod is hinged to the pushing block, and the other end of the force transmission rod is hinged to the block, and the block is movably arranged in the slide groove.

[0011] As a further preference, the transmission mechanism includes a rotating shaft, a gear, a rack and an adjusting rod, one end of the rotating shaft is rotatably connected to the lower inner wall of the positioning groove, the other end of the rotating shaft passes through the upper side wall of the positioning groove and extends to the outside of the fixed seat, the gear is installed at the other end of the rotating shaft, the limit block is fixed on the rotating shaft, a strip groove is provided on one side of the positioning groove, the strip groove is provided along the length direction of the fixed seat, one end of the strip groove is opened to one end surface of the fixed seat, the rack is provided in the strip groove, the rack is meshed with the gear, and the adjusting rod is provided at the other end of the fixed seat, one end of the adjusting rod extends into the strip groove and is rotatably connected to one end of the rack.

[0012] As a further preference, the rack comprises a strip rod, the longitudinal section of the strip rod is convex-shaped, the upper end of the strip rod extends out of the strip groove, and a plurality of tooth blocks are arranged on one side of the upper end of the strip rod.

[0013] As a further preference, the other side surface of the limit block is a slope, an arc surface is provided on one side of one end of the limit block, a positioning block is provided on the other side of one end of the limit block, a protrusion matching the positioning block is provided on one side of the positioning groove, and the rotating shaft is provided close to one end of the limit block.

[0014] Preferably, two ends of the combined steel angle brace are connected to two inner side walls adjacent to the inner truss, and two ends of the combined steel brace and the main brace steel structure are connected to two inner side walls directly opposite to the inner truss.

[0015] A construction method for a foundation pit side truss combined steel support system, comprising the foundation pit side truss combined steel support system, the construction method comprising:

[0016] S1. Establish a foundation pit and measure the strength of the shear stress generated on the inner wall of the foundation pit in advance. Then locate and measure the installation positions of the outer truss and the inner truss inside the foundation pit, and install the outer truss and the inner truss, with the outer truss against the inner wall of the foundation pit.

[0017] S2. Install composite steel angle braces, composite steel braces and main brace steel structures;

[0018] S3. Install the fixed-point stress detection and adjustment mechanism, install the top seat on the outer truss, install the base on the inner truss, hinge one end of the force transmission rod with the push block, and then install the fixed seat on the inner truss;

[0019] S4, driving the screw to move by rotating the hexagonal threaded sleeve, so that the push block squeezes the top seat and the pressure sensor, and monitoring the value of the pressure sensor in real time through the controller, when the value detected by the pressure sensor is equal to or greater than the value of the shear stress, stopping the rotation of the hexagonal threaded sleeve, and recording the value of the pressure sensor at this time as the first value;

[0020] S5. When the shear stress applied to the inner wall of the foundation pit increases, the value detected by the pressure sensor will be greater than the first value, and the pressure sensor will transmit the signal to the controller, which will automatically alarm. At this time, the construction personnel can adjust the fixed-point stress detection and adjustment mechanism in the area where the shear stress increases, so as to apply stronger support force to a certain area of ​​the outer truss.

[0021] The above technical solution has the following advantages or beneficial effects:

[0022] The arrangement of the outer truss, inner truss, combined steel angle brace, combined steel brace and main brace steel structure in the present invention enables the side truss to have a higher supporting strength and can support the inner wall of the foundation pit; through the arrangement of the fixed-point stress detection and adjustment mechanism, the shear stress applied to the inner wall of the foundation pit can be monitored in real time, and a corresponding supporting force can be applied to the outer truss, which can prevent the outer truss from deforming, improve the supporting force of the outer truss, and prevent the inner wall of the foundation pit from deforming or collapsing. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the foundation pit side truss combined steel support system of the present invention;

[0024] Figure 2 It is a side view of the fixed-point stress detection and adjustment mechanism of the present invention;

[0025] Figure 3 is a three-dimensional diagram of the fixed-point stress detection and adjustment mechanism of the present invention;

[0026] Figure 4 yes Figure 3 The enlarged view of point A in the middle;

[0027] Figure 5 It is a structural schematic diagram of the fixing seat in the present invention;

[0028] Figure 6 It is a partial exploded schematic diagram of the fixing seat in the present invention;

[0029] Figure 7 yes Figure 6 The enlarged view of point B in the middle;

[0030] Figure 8 It is a schematic diagram of the structure of the limit block in the present invention;

[0031] Fig. 9 It is a schematic diagram of the screw rod in the present invention cooperating with the top seat and the base;

[0032] Fig.10 yes Fig. 9 Sectional view along CC direction;

[0033] Fig.11 yes Fig.10 The enlarged view of point D in the middle;

[0034] Fig.12 yes Fig.10 Enlarged view of point E in the middle;

[0035] Fig.13 It is a structural schematic diagram of the hexagonal threaded sleeve in the present invention.

[0036] In the figure: 1, outer truss; 2, inner truss; 3, composite steel angle brace; 4, composite steel brace; 5, main brace steel structure; 6, fixed-point stress detection and adjustment mechanism; 601, pressure sensor; 602, top seat; 603, base; 604, push block; 605, screw; 606, fixing rod; 607, hexagonal threaded sleeve; 608, first locking piece; 609, second locking piece; 610, elastic anti-skid pad; 611, follower Force transmission mechanism; 612, fixed plate; 613, first bolt; 614, fixed seat; 615, stopper; 616, spring; 617, limit block; 618, force transmission rod; 619, slide groove; 620, positioning groove; 621, rotating shaft; 622, gear; 623, rack; 624, adjusting rod; 625, strip groove; 626, inclined surface; 627, arc surface; 628, positioning block; 629, protrusion; 630, limit ring. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that, if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, if the terms "first", "second", "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0039] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] Figure 1 It is a structural schematic diagram of the foundation pit side truss combined steel support system of the present invention; Figure 2 It is a side view of the fixed-point stress detection and adjustment mechanism of the present invention; Figure 3 is a three-dimensional diagram of the fixed-point stress detection and adjustment mechanism of the present invention; Figure 4 yes Figure 3 The enlarged view of point A in the middle; Figure 5 It is a schematic diagram of the structure of the fixing seat in the present invention; Figure 6 It is a partial exploded schematic diagram of the fixing seat in the present invention; Figure 7 yes Figure 6 The enlarged view of point B in the middle; Figure 8 It is a schematic diagram of the structure of the limit block in the present invention; Fig. 9 It is a schematic diagram of the screw rod in the present invention cooperating with the top seat and the base; Fig.10 yes Fig. 9 Sectional view along CC direction; Fig.11 yes Fig.10 The enlarged view of point D in the middle; Fig.12 yes Fig.10 Enlarged view of point E in the middle; Fig.13It is a schematic diagram of the structure of the hexagonal threaded sleeve in the present invention. Figures 1 to 13 As shown, a preferred embodiment is shown, which shows a foundation pit side truss combined steel support system for installation in the foundation pit, including an outer truss 1, an inner truss 2, a combined steel angle brace 3, a combined steel brace 4, a main support steel structure 5 and a fixed-point stress detection and adjustment mechanism 6. The outer truss 1 and the inner truss 2 are both arranged in a ring shape, the inner side of the outer truss 1 is arranged with the inner truss 2, a plurality of combined steel angle braces 3 are arranged at the angle position of the inner side of the inner truss 2, a combined steel brace 4 and a main support steel structure 5 are arranged in the middle of the inner side of the inner truss 2, and a plurality of fixed-point stress detection and adjustment mechanisms 6 are arranged between the inner truss 2 and the outer truss 1. In this embodiment, see Figure 1 As shown, guard piles can also be arranged on the outside of the outer truss 1, and the guard piles and the outer truss 1 are connected by a T-shaped force transmission piece. The soil pressure borne by the guard piles can be transmitted to the outer truss 1 through the T-shaped force transmission piece, which serves as the first line of force defense.

[0041] In this embodiment, the outer truss 1 and the inner truss 2 are both rectangular structures, and the composite steel angle braces 3, the composite steel braces 4, and the main support steel structure 5 are arranged in the inner truss 2 to improve the supporting strength of the inner truss 2, so that the inner truss 2 can withstand greater pressure, and the fixed-point stress detection and adjustment mechanism 6 can detect the soil pressure (shear stress) on the local area of ​​the outer truss 1, and can adjust the local supporting force of the outer truss 1, so as to avoid the outer truss 1 from being deformed due to excessive stress for a long time, avoid affecting the normal use next time, and avoid deformation or collapse of the inner wall of the foundation pit.

[0042] Due to the different softness of the soil or the different depths of the foundation pit, the pressure applied to the inner wall of the foundation pit is also different. Therefore, the fixed-point stress detection and adjustment mechanism 6 set in this embodiment can enable the outer truss 1 to adapt to foundation pits of different depths or soil softness. The fixed-point stress detection and adjustment mechanism 6 in this embodiment can be set in several layers according to the depth of the foundation pit.

[0043] Each fixed-point stress detection and adjustment mechanism 6 includes a pressure sensor 601, a top seat 602, a base 603, a pushing block 604, a screw 605, a fixed rod 606, a hexagonal threaded sleeve 607, a first locking member 608, a second locking member 609, an elastic anti-skid pad 610 and a follow-up force transmission mechanism 611. One end of the top seat 602 is connected to the inner wall of the outer truss 1, the base 603 is connected to the outer wall of the inner truss 2, one end of the screw 605 is detachably connected to the other end of the top seat 602, one end of the fixed rod 606 is connected to the base 603, the other end of the fixed rod 606 is rotatably provided with a hexagonal threaded sleeve 607, the other end of the screw 605 is movably provided in the hexagonal threaded sleeve 607 and the fixed rod 606, the other end surface of the top seat 602 is provided with a mounting groove, and the pressure sensor 60 1 is arranged in the installation groove, the pressure sensor 601 is connected to the controller, a push block 604 is arranged on the outer edge of one end of the screw rod 605, the push block 604 contacts the other end surface of the top seat 602 and the pressure sensor 601, planes are arranged on the outer walls of both sides of the screw rod 605, and the elastic anti-skid pad 610 is fixed on the plane, a first locking piece 608 is detachably arranged on the hexagonal threaded sleeve 607, and a second locking piece 609 is detachably arranged on the fixed rod 606, the first locking piece 608 and the second locking piece 609 can both be against the elastic anti-skid pad 610, and a plurality of follow-up force transmission mechanisms 611 are arranged on the periphery of the fixed rod 606, one end of each follow-up force transmission mechanism 611 is respectively hinged to the push block 604, and the other end of each follow-up force transmission mechanism 611 is respectively connected to the outer wall of the inner side truss 2. In this embodiment, the top seat 602 and the outer truss 1 can be connected by bolts, the base 603 and the inner truss 2 can be connected by bolts, and one end of the fixing rod 606 is fixedly connected to the base 603, the pressure sensor 601 is embedded in the installation groove on the base 603, and the hexagonal threaded sleeve 607 and the screw rod 605 are threadedly matched, and the screw rod 605 is moved linearly by rotating the hexagonal threaded sleeve 607. The push block 604 is integrally connected with the screw rod 605, and when the screw rod 605 moves, it can drive the push block 604 to move, so that the push block 604 is pressed on the top seat 602 and the pressure sensor 601, and can apply a supporting force to the top seat 602, and the pressure sensor 601 can detect the pressure applied by the push block 604. The elastic anti-skid gasket 610 is fixed on the screw 605. When the position of the screw 605 is adjusted into place, the elastic anti-skid gasket 610 can be supported by the first locking member 608 and the second locking member 609, thereby fixing the position of the screw 605. This can prevent the threaded matching position between the screw 605 and the hexagonal threaded sleeve 607 from loosening, thereby improving the stability of the support.When the pressure applied locally in the foundation pit increases, the pressure can be transmitted to the top seat 602. At this time, the top seat 602 transmits the pressure to the push block 604, causing the pressure value detected by the pressure sensor 601 to change. Then the pressure sensor 601 transmits the signal to the controller, and the controller issues an alarm to facilitate construction personnel to adjust the fixed-point stress detection and adjustment mechanism 6 in the local area in time, thereby achieving adjustment of the local supporting force and avoiding deformation of the outer truss 1.

[0044] In this embodiment, a rotation groove is formed on the other end surface of the fixing rod 606, and an annular groove is formed on the inner wall of the rotation groove. The structure of the hexagonal threaded sleeve 607 can be seen in Fig.13 As shown, a limit ring 630 is provided at one end of the hexagonal threaded sleeve 607, and one end of the hexagonal threaded sleeve 607 is rotatably disposed in a rotating groove. The limit ring 630 is rotatably disposed in the annular groove to prevent the hexagonal threaded sleeve 607 from being separated from the fixing rod 606.

[0045] In this embodiment, an elastic gasket is arranged between the pushing block 604 and the top seat 602. When the pushing block 604 squeezes the top seat 602, the elastic gasket can be deformed to achieve a buffering effect. When the pressure applied by the foundation pit is transmitted to the top seat 602, the top seat 602 will also squeeze the elastic gasket, causing the elastic gasket to deform.

[0046] The controller in this embodiment is an existing one, which has an alarm and a display screen. The alarm is used to issue an alarm prompt, and the display screen is used to display pressure data.

[0047] When the pushing block 604 is subjected to the pressure exerted by the soil, the pushing block 604 will transfer part of the pressure to the follow-up force transmission mechanism 611 to prevent the screw rod 605 and the fixing rod 606 from being deformed due to excessive pressure.

[0048] Further, as a preferred embodiment, each fixed-point stress detection and adjustment mechanism 6 further includes a fixing plate 612 and a first bolt 613. A positioning hole and a limiting hole that are interconnected are provided in the middle of the top seat 602. The limiting hole is close to one end of the top seat 602, and the positioning hole is close to the other end of the top seat 602. One end of the screw rod 605 is inserted into the positioning hole and extends into the limiting hole. A fixing plate 612 is provided in the limiting hole, and the fixing plate 612 is connected to one end of the screw rod 605 through the first bolt 613. Through the provision of the first bolt 613 and the fixing plate 612, a detachable connection can be achieved between the screw rod 605 and the top seat 602, which is convenient for transportation and replacement.

[0049] Further, as a preferred embodiment, an external thread is provided on the outer wall of the screw 605, and a plane is provided along the axial direction of the screw 605 and divides the external thread into two sections. A plane is provided on the outer wall of the screw 605 to facilitate the installation of the elastic anti-skid pad 610.

[0050] Further, as a preferred embodiment, a first connection hole is provided on each side of the hexagonal threaded sleeve 607, and the first locking member 608 can be disposed in any of the first connection holes, so that the first locking member 608 can always abut against the elastic anti-slip pad 610. The first locking member 608 and the second locking member 609 are both bolts.

[0051] Further, as a preferred embodiment, each follower force transmission mechanism 611 includes a fixed seat 614, a block 615, a spring 616, a transmission mechanism, a limit block 617 and a force transmission rod 618. A slide groove 619 is arranged inside the base 603, and a plurality of positioning grooves 620 are opened on the inner walls on both sides of the slide groove 619. A limit block 617 is rotatably arranged in each positioning groove 620. One end of the spring 616 is connected to one side of the limit block 617, and the other end of the spring 616 is connected to the inner wall of the positioning groove 620. A transmission mechanism is arranged on the fixed seat 614, and the transmission mechanism is connected to the plurality of limit blocks 617 for controlling the limit block 617 to rotate into the positioning groove 620. One end of the force transmission rod 618 is hinged to the pushing block 604, and the other end of the force transmission rod 618 is hinged to the stop block 615. The stop block 615 is movably arranged in the slide groove 619. The limit block 617 can be rotatably arranged in the positioning groove 620, and the spring 616 can make the limit block 617 extend out of the positioning groove 620, thereby blocking the stop block 615 and preventing the stop block 615 from sliding in the slide groove 619. When the screw rod 605 is extended, the push block 604 will drive the force transmission rod 618 to move. At this time, the force transmission rod 618 will drive the stop block 615 to slide in the slide groove 619, and the stop block 615 will squeeze the limit block 617, so that the limit block 617 rotates, and the stopper 617 squeezes the spring 616 and enters the positioning groove 620, which is convenient for the stopper 615 to pass. When the stopper 615 passes, the stopper 617 automatically extends out of the positioning groove 620 under the action of the spring 616, thereby blocking the stopper 615 and preventing the stopper 615 from moving in the opposite direction. After the pusher block 604 is subjected to the pressure of the soil, part of the pressure will be transmitted to the force transmission rod 618, and then transmitted to the fixing seat 614 by the force transmission rod 618. The fixing seat 614 is connected to the inner truss 2 by bolts.

[0052] The position of the fixed-point stress detection and adjustment mechanism 6 between the inner truss 2 and the outer truss 1 in this embodiment can be adjusted as needed, and the number of the fixed-point stress detection and adjustment mechanism 6 can be set as needed.

[0053] Further, as a preferred embodiment, the transmission mechanism includes a rotating shaft 621, a gear 622, a rack 623 and an adjusting rod 624, one end of the rotating shaft 621 is rotatably connected to the lower inner wall of the positioning groove 620, the other end of the rotating shaft 621 passes through the upper side wall of the positioning groove 620 and extends to the outside of the fixed seat 614, the gear 622 is installed on the other end of the rotating shaft 621, the limit block 617 is fixed on the rotating shaft 621, a strip groove 625 is provided on one side of the positioning groove 620, the strip groove 625 is provided along the length direction of the fixed seat 614, one end of the strip groove 625 is opened to one end surface of the fixed seat 614, a rack 623 is provided in the strip groove 625, the rack 623 is meshed with the gear 622, and an adjusting rod 624 is provided at the other end of the fixed seat 614, one end of the adjusting rod 624 extends into the strip groove 625 and is rotatably connected to one end of the rack 623. In this embodiment, the adjusting rod 624 is threadedly connected to the fixing seat 614, one end of the adjusting rod 624 can be connected to the rack 623 through a fixing sleeve, the fixing sleeve and the rack 623 are fixedly connected, and one end of the adjusting rod 624 can rotate in the fixing sleeve and will not be separated from the fixing sleeve. By rotating the adjusting rod 624, the adjusting rod 624 drives the rack 623 to move in the strip groove 625, thereby driving the gear 622 to rotate, and the gear 622 drives the rotating shaft 621 to rotate, and the rotating shaft 621 drives the limit block 617 to rotate and enter the positioning groove 620, so that when the screw rod 605 is retracted, the stop block 615 can slide in the slide groove 619, and when the position of the stop block 615 is adjusted to the right position, the adjusting rod 624 can be rotated, so that the rack 623 drives the gear 622 to rotate, and drives the limit block 617 on the rotating shaft 621 to extend out of the positioning groove 620.

[0054] Further, as a preferred embodiment, the rack 623 includes a bar, the longitudinal section of which is convex, the upper end of the bar extends out of the bar groove 625, and a plurality of tooth blocks are arranged on one side of the upper end of the bar. Figure 6 As shown, the other end of the rack 623 can extend out of the strip groove 625.

[0055] Further, as a preferred embodiment, the other side surface of the limit block 617 is an inclined surface 626, one side of one end of the limit block 617 is provided with an arc surface 627, the other side of one end of the limit block 617 is provided with a positioning block 628, one side of the positioning groove 620 is provided with a protrusion 629 matched with the positioning block 628, and the rotating shaft 621 is provided near one end of the limit block 617. The setting of the inclined surface 626 facilitates the stopper 615 to push the limit block 617 to rotate. When the limit block 617 enters the positioning groove 620, the positioning block 628 and the protrusion 629 are not in contact at this time. When the other end of the limit block 617 extends out of the positioning groove 620 under the action of the spring 616, the positioning block 628 and the protrusion 629 are against each other, which can prevent the stopper 615 from pushing the limit block 617 to rotate in the opposite direction, and at this time, the stopper 615 will always be against the limit block 617 under the action of the force transmission rod 618.

[0056] Further, as a preferred embodiment, the two ends of the composite steel angle brace 3 are connected to the two adjacent inner walls of the inner truss 2, and the two ends of the composite steel brace 4 and the main brace steel structure 5 are connected to the two opposite inner walls of the inner truss 2.

[0057] The above are only preferred embodiments of the present invention, and do not limit the protection scope and implementation methods of the present invention. The present invention also discloses a construction method of a foundation pit side truss combined steel support system on the basis of the above embodiments. The construction method of the foundation pit side truss combined steel support system includes:

[0058] S1. Establish a foundation pit and measure the strength of the shear stress generated on the inner wall of the foundation pit in advance. Then, locate and measure the installation positions of the outer truss 1 and the inner truss 2 inside the foundation pit, and install the outer truss 1 and the inner truss 2, with the outer truss 1 pressed against the inner wall of the foundation pit. The foundation pit side truss combined steel support system in this embodiment can adapt to foundation pits of different depths and foundation pits with different soil hardness. In the case of no retaining piles, the outer truss 1 can be directly in contact with the inner wall of the foundation pit. If retaining piles are set, the retaining piles can be in contact with the inner wall of the foundation pit.

[0059] S2. Install the composite steel angle brace 3, the composite steel brace 4 and the main support steel structure 5. After the inner truss 2 and the outer truss 1 are installed, install the composite steel angle brace 3, the composite steel brace 4 and the main support steel structure 5, and bolt the composite steel angle brace 3, the composite steel brace 4 and the main support steel structure 5 to the inner truss 2 to provide support for the inner truss 2.

[0060] S3, install the fixed-point stress detection and adjustment mechanism 6, install the top seat 602 on the outer truss 1, install the base 603 on the inner truss 2, and hinge one end of the force transmission rod 618 with the push block 604, and then install the fixed seat 614 on the inner truss 2;

[0061] S4. The screw 605 is driven to move by rotating the hexagonal threaded sleeve 607, so that the push block 604 squeezes the top seat 602 and the pressure sensor 601, and the value of the pressure sensor 601 is monitored in real time through the controller. When the value detected by the pressure sensor 601 is equal to or greater than the value of the shear stress, the hexagonal threaded sleeve 607 is stopped from rotating, and the value of the pressure sensor 601 at this time is recorded as the first value; when the shear stress applied by the inner wall of the foundation pit increases, the pressure intensity applied by the inner wall of the foundation pit is the second value. At this time, the value of the second value detected by the pressure sensor 601 will be greater than the first value, and the pressure sensor 601 will transmit a signal to the controller, and the controller will automatically alarm. At this time, the construction personnel can adjust the fixed-point stress detection and adjustment mechanism 6 in the area where the shear stress increases, and apply a stronger supporting force to a certain area of ​​the outer truss 1 to prevent the outer truss 1 from deforming inward.

[0062] The above description is only a preferred embodiment of the present invention, and does not limit the implementation mode and protection scope of the present invention. For those skilled in the art, it should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the description and illustrations of the present invention should be included in the protection scope of the present invention.

Claims

1. A foundation pit side truss combined steel support system, used for installation in a foundation pit, characterized in that: It includes an outer truss, an inner truss, a combined steel angle brace, a combined steel brace, a main brace steel structure and a fixed-point stress detection and adjustment mechanism. The outer truss and the inner truss are both arranged in a ring shape. The inner truss is arranged on the inner side of the outer truss. A plurality of the combined steel angle braces are arranged at the angle position on the inner side of the inner truss. The combined steel brace and the main brace steel structure are arranged at the middle part of the inner side of the inner truss. A plurality of the fixed-point stress detection and adjustment mechanisms are arranged between the inner truss and the outer truss. Each of the fixed-point stress detection and adjustment mechanisms includes a pressure sensor, a top seat, a base, a pushing block, a screw, a fixed rod, a hexagonal threaded sleeve, a first locking piece, a second locking piece, an elastic anti-slip pad and a follow-up force transmission mechanism, one end of the top seat is connected to the inner wall of the outer truss, the base is connected to the outer wall of the inner truss, one end of the screw is detachably connected to the other end of the top seat, one end of the fixed rod is connected to the base, the other end of the fixed rod is rotatably provided with the hexagonal threaded sleeve, the other end of the screw is movably arranged in the hexagonal threaded sleeve and the fixed rod, an installation groove is opened on the other end surface of the top seat, the pressure sensor is arranged in the installation groove, and the pressure sensor is arranged in the installation groove. The sensor is connected to the controller, the pushing block is provided on the outer edge of one end of the screw, the pushing block is in contact with the other end surface of the top seat and the pressure sensor, planes are provided on the outer walls on both sides of the screw, the elastic anti-slip gasket is fixed on the planes, the first locking piece is detachably provided on the hexagonal threaded sleeve, the second locking piece is detachably provided on the fixed rod, the first locking piece and the second locking piece can both be against the elastic anti-slip gasket, a plurality of follow-up force transmission mechanisms are provided on the periphery of the fixed rod, one end of each of the follow-up force transmission mechanisms is respectively hinged to the pushing block, and the other end of each of the follow-up force transmission mechanisms is respectively connected to the outer wall of the inner truss.

2. The foundation pit side truss combined steel support system according to claim 1, characterized in that: Each of the fixed-point stress detection and adjustment mechanisms also includes a fixing plate and a first bolt. A positioning hole and a limiting hole that are interconnected are opened in the middle of the top seat. The limiting hole is close to one end of the top seat, and the positioning hole is close to the other end of the top seat. One end of the screw rod is inserted into the positioning hole and extends into the limiting hole. The fixing plate is arranged in the limiting hole, and the fixing plate is connected to one end of the screw rod through the first bolt.

3. The foundation pit side truss combined steel support system according to claim 1, characterized in that: An external thread is arranged on the outer wall of the screw rod, and the plane is arranged along the axial direction of the screw rod and divides the external thread into two sections.

4. The foundation pit side truss combined steel support system according to claim 1, characterized in that: A first connecting hole is provided on each side surface of the hexagonal threaded sleeve, and the first locking member can be arranged in any one of the first connecting holes.

5. The foundation pit side truss combined steel support system according to claim 1, characterized in that: Each of the follow-up force transmission mechanisms includes a fixed seat, a block, a spring, a transmission mechanism, a limit block and a force transmission rod. A slide groove is arranged inside the base, and a plurality of positioning grooves are opened on the inner walls on both sides of the slide groove. A limit block is rotatably arranged in each of the positioning grooves, one end of the spring is connected to one side of the limit block, and the other end of the spring is connected to the inner wall of the positioning groove. The transmission mechanism is arranged on the fixed seat, and the transmission mechanism is connected to the plurality of limit blocks for controlling the limit block to rotate into the positioning groove. One end of the force transmission rod is hinged to the pushing block, and the other end of the force transmission rod is hinged to the block, and the block is movably arranged in the slide groove.

6. The foundation pit side truss combined steel support system according to claim 5, characterized in that: The transmission mechanism includes a rotating shaft, a gear, a rack and an adjusting rod, one end of the rotating shaft is rotatably connected to the lower inner wall of the positioning groove, the other end of the rotating shaft passes through the upper side wall of the positioning groove and extends to the outside of the fixed seat, the gear is installed at the other end of the rotating shaft, the limit block is fixed on the rotating shaft, a strip groove is provided on one side of the positioning groove, the strip groove is provided along the length direction of the fixed seat, one end of the strip groove is opened to one end surface of the fixed seat, the rack is provided in the strip groove, the rack is meshed with the gear, and the adjusting rod is provided at the other end of the fixed seat, one end of the adjusting rod extends into the strip groove and is rotatably connected to one end of the rack.

7. The foundation pit side truss combined steel support system according to claim 6, characterized in that: The rack comprises a strip bar, the longitudinal section of which is in a convex shape, the upper end of the strip bar extends out of the strip groove, and a plurality of tooth blocks are arranged on one side of the upper end of the strip bar.

8. The foundation pit side truss combined steel support system according to claim 5, characterized in that: The other side surface of the limit block is a slope, an arc surface is provided on one side of one end of the limit block, a positioning block is provided on the other side of one end of the limit block, a protrusion matching with the positioning block is provided on one side of the positioning groove, and the rotating shaft is provided near one end of the limit block.

9. The foundation pit side truss combined steel support system according to claim 1, characterized in that: The two ends of the combined steel angle brace are connected to the two inner side walls adjacent to the inner truss, and the two ends of the combined steel brace and the main brace steel structure are connected to the two inner side walls facing the inner truss.

10. A construction method for a foundation pit side truss combined steel support system, comprising the foundation pit side truss combined steel support system according to any one of claims 1 to 8, characterized in that: The construction method comprises: S1. Establish a foundation pit and measure the strength of the shear stress generated on the inner wall of the foundation pit in advance. Then locate and measure the installation positions of the outer truss and the inner truss inside the foundation pit, and install the outer truss and the inner truss, with the outer truss against the inner wall of the foundation pit. S2. Install composite steel angle braces, composite steel braces and main brace steel structures; S3. Install the fixed-point stress detection and adjustment mechanism, install the top seat on the outer truss, install the base on the inner truss, hinge one end of the force transmission rod with the push block, and then install the fixed seat on the inner truss; S4, driving the screw to move by rotating the hexagonal threaded sleeve, so that the push block squeezes the top seat and the pressure sensor, and monitoring the value of the pressure sensor in real time through the controller, when the value detected by the pressure sensor is equal to or greater than the value of the shear stress, stopping the rotation of the hexagonal threaded sleeve, and recording the value of the pressure sensor at this time as the first value; S5. When the shear stress applied to the inner wall of the foundation pit increases, the value detected by the pressure sensor will be greater than the first value, and the pressure sensor will transmit the signal to the controller, which will automatically alarm. At this time, the construction personnel can adjust the fixed-point stress detection and adjustment mechanism in the area where the shear stress increases, so as to apply stronger support force to a certain area of ​​the outer truss.

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