Prestress-adjustable web member for supporting foundation pit string truss

Abstract

The utility model provides a prestress-adjustable web member for supporting a foundation pit string truss, the bottom of the web member is provided with a movable head, and the left side and the right side between a movable end and a fixed end of the movable head are respectively provided with a jack; the bottom of the jack is fixed to the base of the fixed end, and a piston rod of the jack abuts against the surface of the bottom plate of the movable end. The jack is installed on the adjustable head at the bottom of the web member, the elongation of the adjustable head is adjusted through the jack, and therefore adjustment of prestress can be achieved in the installation stage or the use stage, and effective supporting is provided for the foundation pit enclosing purlin. Furthermore, the base and the bottom plate are connected through a locking mechanism. After the jack is pressurized, locking and pressure maintaining are conducted through the locking mechanism, the jack can be removed after pressure maintaining, operation is convenient and accurate, and the pressure is controllable.

Description

Technical Field

[0001] This utility model relates to the field of tensioned truss support technology for foundation pits, and in particular to a web member for tensioned truss support for foundation pits. Background Technology

[0002] In underground structural engineering, to meet construction excavation conditions and control deformation of the surrounding environment, plate support systems are typically used for foundation pit protection. Traditional plate support systems involve constructing diaphragm walls around the foundation pit to retain the soil, with a support system in the center of the pit serving as a reaction point against the soil walls. Among existing support systems, steel structure support systems, in particular, are widely used due to their advantages such as factory prefabrication of components, convenient on-site construction, and reusability.

[0003] In existing steel structure support systems, walers, chord beams, corner braces, and steel beams are typically the components of the system. Among them, chord beams play a role in increasing the span of the foundation pit, balancing foundation pit deformation, reducing the number of columns, and minimizing the impact on the basement floor slab. Web members are axially compressed members in the chord beams that connect the walers and tie rods / cables, and are used to provide prestress to the walers.

[0004] However, most existing web members are directly connected to the walers via flexible ends, which makes it difficult to provide effective prestress during the web member installation stage. Under long-term support systems, if the web members have insufficient prestress, it is also difficult to adjust and provide effective support for the walers. Utility Model Content

[0005] The purpose of this utility model is to propose a web member for supporting a tensioned truss foundation pit with adjustable end prestress.

[0006] To achieve the above objectives, this utility model proposes a web member for supporting a tensioned truss in a foundation pit with adjustable prestress. The bottom of the web member is equipped with a hinged head, and a jack is installed on each of the left and right sides between the hinged end and the fixed end of the hinged head.

[0007] The bottom of the jack is fixed to the base of the fixed end, and the piston rod of the jack touches the surface of the base plate of the movable end;

[0008] The base and the base plate are connected by a locking mechanism; the locking mechanism includes a screw located in the middle of the base plate and a nut sleeved on the outside of the screw, with one end of the screw inserted into the middle of the fixed end.

[0009] Furthermore, a first flange is welded to the bottom of the web member, and the first flange is connected to the second flange at the fixed end head by high-strength bolts.

[0010] Furthermore, multiple triangular reinforcing ribs are provided between the surface of the first flange and the end of the web member, and these triangular reinforcing ribs are arranged at equal intervals around the web member.

[0011] Furthermore, the bottom plate at the movable end is fixed to the waler of the foundation pit by anchor bars.

[0012] Furthermore, the anchor bar is an L-shaped anchor bar, with one end fixed to the base plate by a nut, and the bent end of the anchor bar pre-embedded in the waler.

[0013] Compared with the prior art, the advantages of this utility model are:

[0014] 1. The bottom of the web member of this utility model is equipped with a jack. The extension of the jack is adjusted by adjusting the extension of the jack, so that the prestress can be adjusted during both the installation and use stages, thereby providing effective support for the foundation pit waler. Furthermore, a locking structure is set up. When the jack is pressurized, it is locked by rotating the nut to maintain the pressure. After maintaining the pressure, the jack can be removed.

[0015] 2. The bottom of the web member is connected to the movable end via a flange and high-strength bolts, ensuring high connection strength and precision. At the same time, the design of the reinforcing ribs effectively strengthens the end strength, ensuring that the end connection does not deform during long-term use, thus ensuring that the web member is always subjected to axial force. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the foundation pit chord beam in an embodiment of this utility model;

[0017] Figure 2 This is a schematic diagram of the overall structure of the web member in an embodiment of this utility model;

[0018] Figure 3 This is an enlarged structural schematic diagram of the hinge head at the end of the web member in an embodiment of this utility model. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be further described below.

[0020] like Figure 2 As shown, this invention proposes a web member for adjustable prestressed tensioned truss support in foundation pits. A movable head 2 is installed at the bottom of the web member 1. A jack 3 is installed on each of the left and right sides between the movable end and the fixed end of the movable head 2. The bottom of the jack 3 is fixed to the base of the fixed end, and the piston rod of the jack 3 contacts the surface of the base plate of the movable end. Figure 1As shown, the adjustable prestressed web member 1 for the tensioned truss support of the foundation pit is mainly used in the chord beam of the steel structure support system of the foundation pit. It is used for the lap support between the arched tie edge of the chord beam and the waler 8, providing a reaction force towards the foundation pit wall and supporting the foundation pit waler 8. The design of the bottom movable head 2 of the web member 1 of this utility model is equipped with a jack 3. The extension of the movable head 2 is adjusted by the jack 3, so that the prestress of the waler 8 can be adjusted during both the installation and use stages, ensuring that the web member 1 provides effective support for the foundation pit waler 8. Furthermore, the base and the bottom plate are connected by a locking mechanism; the locking mechanism includes a screw 9 located in the middle of the bottom plate and a nut 10 sleeved on the screw 9, with one end of the screw 9 inserted into the middle of the fixed end. When the jack is pressurized, the nut 10 is rotated so that it touches the surface of the base to lock and maintain pressure. After maintaining pressure, the jack can be removed. The operation is convenient, precise and the pressure is controllable.

[0021] In this embodiment, to ensure the strength of the web member 1, a first flange 4 is welded to the bottom of the web member 1. The first flange 4 is connected to the second flange 5 at the fixed end by high-strength bolts. Multiple triangular reinforcing ribs 6 are provided between the surface of the first flange 4 and the end of the web member 1, and the multiple triangular reinforcing ribs 6 are arranged at equal intervals around the circumference of the web member 1. The design of the reinforcing ribs 6 and the high-strength bolts effectively strengthens the end of the web member 1, ensuring that the connection of the web member 1 does not deform during long-term use, and further ensuring that the web member 1 is always subjected to axial force.

[0022] In this embodiment, to ensure the connection strength between the web member 1 and the waler 8, such as... Figure 3 As shown, the bottom plate of the movable end is fixed to the waler 8 of the foundation pit by anchor bars 7. The anchor bars 7 are L-shaped anchor bars 7, one end of the anchor bar 7 is fixed to the bottom plate by a nut 10, and the bent end of the anchor bar 7 is pre-embedded in the waler 8.

[0023] The above are merely preferred embodiments of this utility model and do not constitute any limitation on this utility model. Any equivalent substitutions or modifications made by those skilled in the art to the technical solutions and contents disclosed in this utility model without departing from the scope of the technical solutions of this utility model shall still fall within the protection scope of this utility model.

Claims

1. A web member for adjustable prestressed tensioned truss support in foundation pits, characterized in that, A hinged head is installed at the bottom of the brace, and a jack is installed on each of the left and right sides between the hinged end and the fixed end of the hinged head; The bottom of the jack is fixed to the base of the fixed end, and the piston rod of the jack touches the surface of the bottom plate of the movable end. The base and the bottom plate are connected by a locking mechanism; the locking mechanism includes a screw located in the middle of the bottom plate and a nut sleeved on the screw, with one end of the screw inserted into the middle of the fixed end.

2. The adjustable prestressed web member for a tensioned truss support in a foundation pit according to claim 1, characterized in that, A first flange is welded to the bottom of the web member, and the first flange is connected to the second flange at the fixed end head by high-strength bolts.

3. The adjustable prestressed web member for a tensioned truss support in a foundation pit according to claim 2, characterized in that, Multiple triangular reinforcing ribs are provided between the surface of the first flange and the end of the web member, and the multiple triangular reinforcing ribs are arranged at equal intervals around the web member.

4. The adjustable prestressed web member for a tensioned truss support in a foundation pit according to claim 1, characterized in that, The bottom plate of the movable end is fixed to the waler of the foundation pit by anchor bars.

5. The adjustable prestressed web member for a tensioned truss support in a foundation pit according to claim 4, characterized in that, The anchor bar is an L-shaped anchor bar, one end of which is fixed to the base plate by a nut, and the bent end of the anchor bar is embedded in the waler.

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