A foundation pit side truss combined steel support system and construction method thereof

Abstract

The present invention discloses a foundation pit side truss combined steel support system and a construction method thereof, which is used to be installed in a foundation pit and includes an outer truss, an inner truss, a combined steel angle brace, a combined steel brace, a main support steel structure, and a fixed-point stress detection and adjustment mechanism. Each fixed-point stress detection and adjustment mechanism includes a pressure sensor, a top seat, a base, a push block, a screw, a fixed rod, a hexagonal threaded sleeve, a first locking member, a second locking member, an elastic anti-slip gasket, and a follow-up force transmission mechanism. By setting 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.

Description

Technical Field

[0001] The present 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 in the development of urban underground spaces is deeper excavation and larger spaces. Currently, foundation pit support is achieved by installing a circle of side trusses and steel support structures inside the pit. The steel support structures are fixed to the inside of the side trusses, allowing the side trusses to support the inner wall of the pit. However, since the upper periphery of the pit is often subjected to large loads, when the load increases to a certain level, the shear stress in a certain direction in a certain area inside the pit increases, causing the side trusses to be squeezed in a certain area of ​​the inner wall of the pit, causing the side trusses to deform. This not only affects the normal use of the side trusses at the next time, but can also easily lead to landslides in parts of the 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 in the present invention is as follows:

[0005] A foundation pit side truss combined steel support system, for installation in a foundation pit, comprising an outer truss, an inner truss, a combined steel angle brace, a combined steel brace, a main support 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 an angle position on the inner side of the inner truss. The combined steel brace and the main support steel structure are arranged in the middle 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.

[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 gasket 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 provided in the hexagonal threaded sleeve and the fixed rod, the other end surface of the top seat is provided with a mounting groove, the pressure sensor is provided in the mounting groove, the pressure sensor The sensor is connected to the controller, and the pushing block is provided on the outer edge of one end of the screw, and 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 of both sides of the screw, and the elastic anti-slip gasket is fixed on the plane. The first locking piece is detachably provided on the hexagonal threaded sleeve, and the second locking piece is detachably provided on the fixed rod. Both the first locking piece and the second locking piece can be against the elastic anti-slip gasket, and a plurality of follow-up force transmission mechanisms are provided on the periphery of the fixed rod, and one end of each follow-up force transmission mechanism is respectively hinged to the pushing block, and the other end of each follow-up force transmission mechanism 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, and 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 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 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 stop block, a spring, a transmission mechanism, a limit block and a force transmission rod, a slide groove is provided inside the base, and a plurality of positioning grooves are provided on the inner walls on both sides of the slide groove, and a limit block is rotatably provided 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 provided 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 push block, and the other end of the force transmission rod is hinged to the stop block, and the stop block is movably provided 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, one side of the positioning groove is provided with a strip groove, the strip groove is arranged 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 other end of the fixed seat is provided with the adjusting rod, 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 includes 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 provided 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 is provided on one side of the positioning groove to cooperate with the positioning block, and the rotating shaft is provided close to one end of the limit block.

[0014] Preferably, both ends of the composite steel angle brace are connected to the two adjacent inner side walls of the inner truss, and both ends of the composite steel brace and the main support steel structure are connected to the two opposite inner side walls of 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. Set up a foundation pit and pre-measure the shear stress intensity generated on the inner wall of the foundation pit. 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, placing the outer truss against the inner wall of the foundation pit.

[0017] S2. Install composite steel angle braces, composite steel braces and main support 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 to the push block, and then install the fixed seat on the inner truss;

[0019] S4. The screw is driven to move by rotating the hexagonal threaded sleeve so that the push block squeezes the top seat and the pressure sensor, and the value of the pressure sensor is monitored in real time by the controller. When the value detected by the pressure sensor is equal to or greater than the value of the shear stress, the rotation of the hexagonal threaded sleeve is stopped, and the value of the pressure sensor at this time is recorded 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. The pressure sensor will transmit the 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 in the area where the shear stress increases 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, composite steel angle brace, composite steel brace and main support steel structure in the present invention enables the side truss to have a higher supporting strength and to 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 diagram of the foundation pit side truss combined steel support system of the present invention;

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

[0025] Figure 3 1 is a perspective view of the fixed-point stress detection and adjustment mechanism of the present invention;

[0026] Figure 4 yes Figure 3 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 Enlarged view of point B in the middle;

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

[0031] Figure 9 It is a schematic diagram of the screw rod, the top seat and the base in the present invention;

[0032] Figure 10 yes Figure 9 Cross-sectional view in CC direction;

[0033] Figure 11 yes Figure 10 Enlarged view of point D in the middle;

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

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

[0036] Figure: 1, outer truss; 2, inner truss; 3, composite steel angle brace; 4, composite steel brace; 5, main support 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 member; 609, second locking member; 610, elastic anti-slip gasket; 611, follower Force transmission mechanism; 612, fixed plate; 613, first bolt; 614, fixed seat; 615, stop block; 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 clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0038] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not intended to indicate or imply relative importance.

[0039] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific contexts.

[0040] Figure 1 It is a structural diagram of the foundation pit side truss combined steel support system of the present invention; Figure 2 is a side view of the fixed-point stress detection and adjustment mechanism of the present invention; Figure 3 1 is a perspective view of the fixed-point stress detection and adjustment mechanism of the present invention; Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 It is a structural schematic diagram 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 Enlarged view of point B in the middle; Figure 8 It is a schematic structural diagram of the limit block in the present invention; Figure 9 It is a schematic diagram of the screw rod, the top seat and the base in the present invention; Figure 10 yes Figure 9 Cross-sectional view in CC direction; Figure 11 yes Figure 10 Enlarged view of point D in the middle; Figure 12 yes Figure 10 Enlarged view of point E in the middle; Figure 13This 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 provided with an inner truss 2, a plurality of combined steel angle braces 3 are provided at the inner angle position of the inner side of the inner truss 2, a combined steel brace 4 and a main support steel structure 5 are provided at the inner middle part of the inner truss 2, and a plurality of fixed-point stress detection and adjustment mechanisms 6 are provided between the inner truss 2 and the outer truss 1. In this embodiment, see Figure 1 As shown, guard piles can also be provided 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, acting as the first line of defense.

[0041] In this embodiment, the outer truss 1 and the inner truss 2 are both rectangular structures, and the composite steel angle brace 3, the composite steel brace 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, which can 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] Because the pressure exerted on the inner wall of a foundation pit varies depending on the softness of the soil or the depth of the foundation pit, the fixed-point stress detection and adjustment mechanism 6 provided in this embodiment enables the outer truss 1 to adapt to foundation pits of varying depths or soil softness. The fixed-point stress detection and adjustment mechanism 6 in this embodiment can be provided in multiple layers depending on 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-slip gasket 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, and 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, and 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. A mounting groove is provided on the surface of the other end of the top seat 602. 1 is arranged in the installation groove, the pressure sensor 601 is connected to the controller, a pushing block 604 is provided on the outer edge of one end of the screw rod 605, and the pushing block 604 contacts the other end surface of the top seat 602 and the pressure sensor 601. Flat surfaces are provided on the outer walls of both sides of the screw rod 605, and elastic anti-slip pads 610 are fixed on the flat surfaces. A first locking piece 608 is detachably provided on the hexagonal threaded sleeve 607, and a second locking piece 609 is detachably provided on the fixed rod 606. Both the first locking piece 608 and the second locking piece 609 can be abutted against the elastic anti-slip pad 610. A plurality of follow-up force transmission mechanisms 611 are provided on the periphery of the fixed rod 606, one end of each follow-up force transmission mechanism 611 is respectively hinged to the pushing block 604, and the other end of each follow-up force transmission mechanism 611 is respectively connected to the outer wall of the inner 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 mounting groove of the base 603, and the hexagonal threaded sleeve 607 is threadedly engaged with the screw 605. By rotating the hexagonal threaded sleeve 607, the screw 605 is linearly moved. The push block 604 is integrally connected to the screw 605. When the screw 605 moves, it can drive the push block 604 to move, so that the push block 604 is pressed against the top seat 602 and the pressure sensor 601, which can apply a supporting force to the top seat 602. The pressure sensor 601 can detect the pressure applied by the push block 604. The elastic anti-slip gasket 610 is fixed on the screw 605. When the position of the screw 605 is adjusted to the right position, the first locking member 608 and the second locking member 609 can be used to support the elastic anti-slip gasket 610, thereby fixing the position of the screw 605. This can prevent the threaded fitting 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 prompt, so that the construction personnel can adjust the fixed-point stress detection and adjustment mechanism 6 in the local area in time, thereby realizing the adjustment of the local support force and avoiding deformation of the outer truss 1.

[0044] In this embodiment, a rotation groove is provided on the other end surface of the fixing rod 606, and an annular groove is provided on the inner wall of the rotation groove. The structure of the hexagonal threaded sleeve 607 can be seen in FIG. Figure 13 As shown, a limiting ring 630 is provided at one end of the hexagonal threaded sleeve 607. One end of the hexagonal threaded sleeve 607 is rotatably disposed in the rotating groove. The limiting ring 630 is rotatably disposed in the annular groove to prevent the hexagonal threaded sleeve 607 from separating 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 have 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] Furthermore, 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 opened 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 via the first bolt 613. The provision of the first bolt 613 and the fixing plate 612 enables a detachable connection between the screw rod 605 and the top seat 602, facilitating transportation and replacement.

[0049] Furthermore, 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. The plane is provided on the outer wall of the screw 605 to facilitate the installation of the elastic anti-slip gasket 610.

[0050] Furthermore, as a preferred embodiment, a first connection hole is formed 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 gasket 610. The first locking member 608 and the second locking member 609 are both bolts.

[0051] Furthermore, as a preferred embodiment, each follower force transmission mechanism 611 includes a fixed seat 614, a stopper 615, a spring 616, a transmission mechanism, a limit block 617 and a force transmission rod 618. A slide groove 619 is provided inside the base 603, and a plurality of positioning grooves 620 are provided on the inner walls on both sides of the slide groove 619. A limit block 617 is rotatably provided 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 provided 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 push block 604, and the other end of the force transmission rod 618 is hinged to the stopper 615. The stopper 615 is movably provided 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 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 limit block 617 compresses the spring 616 and enters the positioning groove 620, facilitating the passage of the stop block 615. When the stop block 615 passes, the limit block 617 automatically extends out of the positioning groove 620 under the action of the spring 616, thereby blocking the stop block 615 and preventing the stop block 615 from moving in the opposite direction. When the push block 604 is subjected to the pressure of the soil, part of the pressure is transmitted to the force transmission rod 618, which is then transmitted to the fixed seat 614. The fixed 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 mechanisms 6 can be set as needed.

[0053] Furthermore, 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, and 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, and 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 meshes with the gear 622. 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 base 614. One end of the adjusting rod 624 can be connected to the rack 623 via a fixing sleeve. The fixing sleeve and the rack 623 are fixedly connected. One end of the adjusting rod 624 can rotate within the fixing sleeve without being separated from the fixing sleeve. By rotating the adjusting rod 624, the adjusting rod 624 drives the rack 623 to move within the strip groove 625, thereby driving the gear 622 to rotate. The gear 622 drives the rotating shaft 621 to rotate. The rotating shaft 621 drives the stopper 617 to rotate and enter the positioning groove 620. When the screw 605 is retracted, the stopper 615 can slide within the slide groove 619. When the position of the stopper 615 is adjusted to the correct position, the adjusting rod 624 can be rotated, causing the rack 623 to drive the gear 622 to rotate, driving the stopper 617 on the rotating shaft 621 to extend out of the positioning groove 620.

[0054] Furthermore, as a preferred embodiment, the rack 623 includes a bar, the longitudinal section of which is convex, the upper end of which extends out of the bar groove 625, and a plurality of tooth blocks are provided on one side of the upper end of the bar. The structure of the rack 623 can be seen in FIG. Figure 6 As shown, the other end of the rack 623 can extend out of the strip-shaped slot 625 .

[0055] Furthermore, as a preferred embodiment, the other side surface of the stop block 617 is formed as an inclined surface 626. A curved surface 627 is provided on one side of one end of the stop block 617. A positioning block 628 is provided on the other side of one end of the stop block 617. A protrusion 629 is provided on one side of the positioning slot 620 to cooperate with the positioning block 628. The rotation axis 621 is disposed near one end of the stop block 617. The provision of the inclined surface 626 facilitates the stop block 615 in pushing the stop block 617 for rotation. When the stop block 617 enters the positioning slot 620, the positioning block 628 and the protrusion 629 do not contact each other. When the other end of the stop block 617 extends out of the positioning slot 620 under the action of the spring 616, the positioning block 628 and the protrusion 629 abut against each other, preventing the stop block 615 from pushing the stop block 617 in the opposite direction. At this time, the stop block 615, under the action of the force transmission rod 618, always abuts against the stop block 617.

[0056] Furthermore, 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 support 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 scope of protection and implementation of the present invention. Based on the above embodiments, the present invention further discloses a construction method of a foundation pit side truss combined steel support system. 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, composite steel brace 4 and main support steel structure 5; after the inner truss 2 and the outer truss 1 are installed, install the composite steel angle brace 3, composite steel brace 4 and main support steel structure 5, and bolt the composite steel angle brace 3, composite steel brace 4 and 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, the base 603 on the inner truss 2, and hinge one end of the force transmission rod 618 to the push block 604. 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 rotation of the hexagonal threaded sleeve 607 is stopped, 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. 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 to 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 for installation in a foundation pit, characterized in that: It includes an outer truss, an inner truss, a composite steel angle brace, a composite steel brace, a main support 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 composite steel angle braces are arranged at the angle position on the inner side of the inner truss. The composite steel brace and the main support steel structure are arranged in the middle part of the inner side of the inner truss. A plurality of 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 gasket 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 provided in the hexagonal threaded sleeve and the fixed rod, the other end surface of the top seat is provided with a mounting groove, the pressure sensor is provided in the mounting groove, the pressure sensor 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, flat surfaces are provided on the outer walls of both sides of the screw, the elastic anti-slip gasket is fixed on the flat surfaces, the first locking piece is detachably provided on the hexagonal threaded sleeve, the second locking piece is detachably provided on the fixing rod, the first locking piece and the second locking piece are both capable of abutting against the elastic anti-slip gasket, a plurality of follow-up force transmission mechanisms are provided on the periphery of the fixing 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; Each of the follow-up force transmission mechanisms includes a fixed seat, a stop block, a spring, a transmission mechanism, a limit block and a force transmission rod. A slide groove is provided inside the base, and a plurality of positioning grooves are provided on the inner walls on both sides of the slide groove. A limit block is rotatably provided 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 provided 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 stop block, and the stop block is movably provided in the slide groove.

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 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 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 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.

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 disposed 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: 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, one side of the positioning groove is provided with a strip groove, the strip groove is arranged 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 other end of the fixed seat is provided with the adjusting rod, one end of the adjusting rod extends into the strip groove and is rotatably connected to one end of the rack.

6. The foundation pit side truss combined steel support system according to claim 5, characterized in that: The rack comprises a strip rod, the longitudinal section of which 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.

7. 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 that cooperates 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.

8. 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 adjacent inner side walls of the inner truss, and the two ends of the combined steel brace and the main support steel structure are connected to the two opposite inner side walls of the inner truss.

9. 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 7, characterized in that: The construction method comprises: S1. Set up a foundation pit and pre-measure the shear stress intensity generated on the inner wall of the foundation pit. 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, placing the outer truss against the inner wall of the foundation pit. S2. Install composite steel angle braces, composite steel braces and main support 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 to the push block, and then install the fixed seat on the inner truss; S4. The screw is driven to move by rotating the hexagonal threaded sleeve so that the push block squeezes the top seat and the pressure sensor, and the value of the pressure sensor is monitored in real time by the controller. When the value detected by the pressure sensor is equal to or greater than the value of the shear stress, the rotation of the hexagonal threaded sleeve is stopped, and the value of the pressure sensor at this time is recorded 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. The pressure sensor will transmit the 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 in the area where the shear stress increases to apply stronger support force to a certain area of ​​the outer truss.

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