A method for stabilizing the waist beam based on smooth supporting piles

Abstract

The present invention discloses a method for stabilizing the waist beam based on smooth supporting piles, the construction method comprising measurement and positioning, supporting piles, water stop pile construction and the first layer of earthwork excavation, crown beam, crown beam connecting tie steel bars and the first prestressed anchor cable construction, second layer of earthwork excavation, waist beam, waist beam connecting tie steel bars and the second prestressed anchor cable construction, and connecting tie steel bar fixing construction. The construction method provided by the present invention can change the traditional waist beam construction method, avoid the damage of the prestressed structure of the smooth supporting piles themselves, ensure the normal functioning of the foundation pit support system, and make the waist beam subject to gravity, the tension provided by the vertical tie steel bars, the prestress of the second prestressed anchor cable, and the reaction force of the supporting piles on the waist beam, forming a force balance, changing the unbalanced force state of the waist beam, and making the waist beam better play the role of the foundation pit support system.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit and slope support construction, and in particular to a waist beam stabilization construction method based on smooth support piles. Background Art

[0002] In the field of construction, support piles are usually used for deep foundation pit support. The existing support piles are usually cast-in-place concrete pipe piles, and waist beam concrete is often provided on the cast-in-place concrete pipe piles. The traditional construction process of cast-in-place concrete pipe piles and waist beams is usually that the waist beam is attached to the side wall of the cast-in-place concrete pile, and the waist beam is connected by the pile body chiseling and planting reinforcement. The traditional waist beam construction process is applied to the position of large-diameter prestressed concrete pipe piles as support piles, and there are the following shortcomings:

[0003] 1) Due to the high concrete strength of prestressed concrete pipe piles and the presence of prestress inside the pile body, the pile body of prestressed concrete pipe piles is not suitable for roughening and rebar planting, and the outer wall of prestressed concrete pipe piles is relatively smooth, resulting in the waist beam concrete itself cannot form a reliable connection with the pipe pile;

[0004] 2) The outer wall of the prestressed concrete pile is relatively smooth, which not only makes it difficult to drill holes for planting reinforcement, but also damages the prestressed concrete pile, reducing the internal prestress and local force-bearing capacity of the prestressed concrete pile;

[0005] 3) During the curing period, the waist beam concrete is subjected to gravity before the anchor cable is prestressed, which makes it very easy to slide downward, settle unevenly, and form vertical cracks. The existing construction waist beam slides downward, which will cause micro cracks in the waist beam and change the vertical stress surface angle of the anchor plate base, making it impossible to form an overall consistent stress angle. When the anchor cable is prestressed in the later stage, it will accelerate the sliding, cracking and deformation of the waist beam, which will have an adverse effect on the overall stress system of the foundation pit support, resulting in safety hazards in the foundation pit excavation stage and the main structure construction stage, which is not conducive to the progress of the foundation pit support construction. Summary of the invention

[0006] The technical problem to be solved by the present invention is to provide a construction method for the defects existing in the prior art, which can solve the problem that the smooth supporting pile body cannot be used as a reinforcement anchoring object by utilizing part of the foundation pit support system, optimizing the construction process, changing the traditional waist beam construction method, and avoiding the damage of the prestressed structure of the smooth supporting pile itself by utilizing the improved construction process of the present invention, thereby ensuring the normal functioning of the foundation pit support system.

[0007] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0008] A method for stabilizing a waist beam based on smooth supporting piles, the method comprising the following steps:

[0009] Step 1) measurement and positioning;

[0010] Step 2) Construction of support piles, water-stop piles and first-layer earthwork excavation: Use a large-diameter drill-and-drill rig to construct a number of vertically parallel smooth support piles around the foundation pit;

[0011] Step 3) Construction of the crown beam, crown beam connecting tie steel bars and the first prestressed anchor cable: Use an excavator to dig a crown beam groove at the top of the smooth support pile, implant the connecting main bars in the smooth support pile, tie the crown beam main bars in the crown beam groove, weld the crown beam main bars to the connecting main bars of the smooth support pile, embed the crown beam connecting tie steel bars in the crown beam groove, leave the end when embedding the crown beam connecting tie steel bars in the crown beam groove, and construct and install the first prestressed anchor cable on the crown beam between two adjacent smooth support piles;

[0012] Step 4) Excavation of the second layer of earthwork;

[0013] Step 5) Construction of waist beam, waist beam connecting tie steel bars and second prestressed anchor cable: tie waist beam horizontal reinforcement bars at a preset depth of the foundation pit near the smooth support piles, embed waist beam connecting tie steel bars in the waist beam, leave the ends when embedding waist beam connecting tie steel bars, install waist beam template, pour waist beam concrete, and construct and install the second prestressed anchor cable at the waist beam position of two adjacent smooth support piles;

[0014] Step 6) Construction of fixing the connecting tie steel bars: Weld and fix the end portion left when the crown beam connecting tie steel bars are pre-buried with the end portion left when the waist beam connecting tie steel bars are pre-buried.

[0015] Furthermore, one end of the crown beam connecting tie steel bar is bent to form a first hook, and the first hook at one end of the crown beam connecting tie steel bar hooks the crown beam main reinforcement inside the crown beam.

[0016] Furthermore, one end of the waist beam connecting tie steel bar is bent to form a second hook, and the second hook at one end of the waist beam connecting tie steel bar hooks the waist beam horizontal steel bar inside the waist beam.

[0017] Furthermore, the first hook of the crown beam connecting the tie steel bar is anchored into the crown beam to a depth of 40 cm, and the second hook of the waist beam connecting the tie steel bar is anchored into the waist beam to a depth of 40 cm.

[0018] Furthermore, the smooth support piles in step 2) are continuously constructed by using the pre-hole non-squeezing soil drilling and pipe pile method, and the pile ends of the smooth support piles can be embedded in the medium-weathered muddy siltstone.

[0019] Furthermore, a support plate is fixed radially inside the top of the smooth supporting pile in step 2), and a number of connecting main bars are fixed above the support plate by core-filling concrete. The connecting main bars are evenly arranged in a circle around the inner wall of the smooth supporting pile and are connected into one by supporting stirrups. Concrete is poured into the core of the smooth supporting pile to form a whole with the crown beam. One end of each connecting main bar is a right-angle bend section, and the other end is a vertical section. The connecting main bar is anchored into the crown beam through the right-angle bend, and the connecting main bar is vertically toward the pile wall of the smooth supporting pile through the vertical section.

[0020] Furthermore, in step 3), after the ends of the pre-embedded crown beam connecting tie bars are reserved, a crown beam formwork is installed on the side of the crown beam main reinforcement, and the crown beam concrete is poured. After the concrete solidifies, the crown beam formwork is removed.

[0021] Furthermore, in step 6), the horizontal steel bars of the waist beam are distributed at equal intervals on the waist beam, and a waist beam steel bar cage is embedded on the edge of the waist beam, and the waist beam steel bar cage is composed of waist beam stirrups tied to the outside of the horizontal steel bars of the waist beam.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1) The construction method of the present invention includes measurement and positioning, construction of supporting piles, water-stop piles and the first layer of earth excavation, construction of the crown beam, crown beam connecting tie steel bars and the first prestressed anchor cable, construction of the second layer of earth excavation, waist beam, waist beam connecting tie steel bars and the second prestressed anchor cable, and connecting tie steel bar fixing construction. The construction method provided by the present invention can change the traditional waist beam construction method, solve the problem that the smooth supporting pile body is not suitable as a reinforcement anchor object, and the improved construction process of the present invention can avoid the destruction of the prestressed structure of the smooth supporting pile itself, ensure the normal functioning of the foundation pit support system, and provide an effective method for creating high-quality products. The construction method of the present invention can use the crown beam to provide an upward constraint force for the waist beam, which is strong and reliable, plays an anti-slip role, effectively resists the slippage of the concrete waist beam, and has a significant effect on protecting the structural integrity of the waist beam. The construction method provided by the present invention is simple to operate, safe and reliable, and is an advanced and safe construction process.

[0024] 2) The construction method of the present invention pre-buries the crown beam connecting tie steel bars in the crown beam, pre-buries the waist beam connecting tie steel bars in the waist beam, and welds the end portion reserved when the crown beam connecting tie steel bars are pre-buried with the end portion reserved when the waist beam connecting tie steel bars are pre-buried, so as to ensure that the waist beam has an upward constraint force, and has high resource utilization rate. The vertical tie steel bars can stabilize the vertical position of the waist beam before the second prestressed anchor cable applies prestress, and ensure that the waist beam does not slide down or deform. In addition, after the vertical tie steel bars are constructed between the crown beam and the waist beam, the waist beam is subjected to gravity, the tension provided by the vertical tie steel bars, the prestress of the second prestressed anchor cable, and the reaction force of the supporting piles on the waist beam, forming a force balance, changing the unbalanced force state of the waist beam, and enabling the waist beam to better play the role of the foundation pit support system. The vertical tie steel bars constructed by the present invention have a simple structure, convenient construction, low cost, and high cost performance, and can reduce construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the process of the waist beam stabilization construction method based on smooth supporting piles of the present invention;

[0026] Figure 2 It is a vertical view of the smooth support pile, the crown beam and the waist beam of the present invention;

[0027] Figure 3 It is a side view of the smooth support pile, the crown beam and the waist beam of the present invention;

[0028] Figure 4 It is a large-scale drawing of the crown beam pre-embedded crown beam connecting tie steel bars and the waist beam pre-embedded waist beam connecting tie steels of the present invention;

[0029] Figure 5 It is a large-scale drawing of the connection between the smooth supporting pile and the crown beam of the present invention;

[0030] Figure 6 It is a vertical view of the waist beam of the present invention.

[0031] In the figure: foundation pit 1, guardrail 11, miscellaneous fill layer 12, silty clay layer 13, fine sand layer 14, fully weathered muddy siltstone layer 15, moderately weathered muddy siltstone layer 16, slope 17, smooth support piles 2, connecting main reinforcement 21, support plate 22, supporting stirrups 23, water stop piles 3, first prestressed anchor cable 4, crown beam 5, crown beam main reinforcement 51, waist beam 6, waist beam horizontal reinforcement 61, waist beam reinforcement cage 62, second prestressed anchor cable 7, crown beam connecting tie reinforcement 8, first hook 81, waist beam connecting tie steel 9, second hook 91. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings, which are part of this specification and illustrate the principles of the present invention through embodiments. Other aspects, features and advantages of the present invention will become clear from the detailed description. In the drawings referred to, the same or similar parts in different figures are represented by the same reference numerals.

[0033] like Figure 1-6 As shown, the first embodiment of the present invention provides a method for stabilizing the waist beam 6 based on the smooth support piles 2, and the construction method includes the following process:

[0034] Step 1) Measurement and positioning: According to the requirements of the project plane coordinates and elevation, coordinate calculation is performed to encrypt and lay out the control points of each section. The foundation pit 1 adopts the reinforcement support type of "upper slope 17 + support piles + two prestressed anchor cables + mixing piles", where the top elevation of the foundation pit 1 is 23.5m, the bottom elevation of the foundation pit 1 is -11m, the upper slope 17 height is 2m, and the pile positions of the water stop pile 3 and the support pile are placed out of the center point. The pile position of the support pile is not greater than 100mm, and the positioning deviation of the water stop pile 3 does not exceed 50mm. The elevation needs to be measured before the excavation of the first and second layers of earthwork to ensure the working platform requirements of the crown beam 5 and the waist beam 6 to avoid over-excavation;

[0035] Step 2) Construction of support piles and water-stop piles 3 and excavation of the first layer of earthwork: Use a large-diameter drill-and-drill rig to construct a number of vertically parallel smooth support piles 2 around the foundation pit 1;

[0036] Step 3) Construction of the crown beam 5, the crown beam connecting tie steel bars 8 and the first prestressed anchor cable 4: Use an excavator to dig out a crown beam 5 groove at the top position of the smooth supporting pile 2, implant the connecting main bars 21 in the smooth supporting pile 2, tie the crown beam main bars 51 in the crown beam 5 groove, weld the crown beam main bars 51 to the connecting main bars 21 of the smooth supporting pile 2, embed the crown beam connecting tie steel bars 8 in the crown beam 5 groove, leave the end when embedding the crown beam connecting tie steel bars 8 in the crown beam 5 groove, construct and install the first prestressed anchor cable 4 on the crown beam 5 between two adjacent smooth supporting piles 2, anchor the anchor section of the first prestressed anchor cable 4 in the soil layer outside the foundation pit 1, and fix the free section of the first prestressed anchor cable 4 on the crown beam 5;

[0037] Step 4) Excavation of the second layer of earthwork: The excavation process of the foundation pit 1 is carried out in a layered and segmented manner. When the concrete strength of the crown beam 5 reaches the design strength, the second layer of earthwork is excavated;

[0038] Step 5) Construction of the waist beam 6, the waist beam connecting tie steel bars 9 and the second prestressed anchor cable 7: tie the waist beam horizontal reinforcement 61 at a preset depth of the foundation pit 1 near the smooth supporting pile 2, pre-embed the waist beam connecting tie steel bars 9 in the waist beam 6, leave the end when pre-embed the waist beam connecting tie steel bars 9, install the waist beam 6 template, pour the waist beam 6 concrete, construct and install the second prestressed anchor cable at the waist beam 6 position of two adjacent smooth supporting piles 2, the anchoring section of the second prestressed anchor cable 7 is anchored in the soil layer outside the foundation pit 1, the free section of the second prestressed anchor cable 7 is fixed on the waist beam 6, the second prestressed anchor cable 7 passes through the waist beam 6 concrete of the two adjacent smooth supporting piles 2, remove the side form of the waist beam 6 template 48 hours after the waist beam 6 concrete is poured, and clean the tensioned end of the second prestressed anchor cable 7, after the waist beam 6 concrete age expires, tension and lock the second prestressed anchor cable 7 according to the construction specification to provide prestress for the second prestressed anchor cable 7;

[0039] Step 6) Construction of fixing the connecting tie steel bars: The end portion of the crown beam connecting tie steel bars 8 reserved when pre-embedded is welded and fixed with the end portion of the waist beam connecting tie steel bars 9 reserved when pre-embedded.

[0040] The present invention also sets two protective railings 11 with Ф48mm steel pipes around the foundation pit 1. The spacing between the protective railings 11 is 2m, 1.2m above the natural floor, and 0.8m buried deep. The soil of the foundation pit 1 is composed of a miscellaneous fill layer 12, a silty clay layer 13, a fine sand layer 14, a fully weathered muddy siltstone layer 15, and a moderately weathered muddy siltstone layer 16 from top to bottom.

[0041] The present invention pre-embeds the crown beam connecting tie steel bars 8 in the crown beam 5, pre-embeds the waist beam connecting tie steel bars 9 in the waist beam 6, and welds the end portions reserved when the crown beam connecting tie steel bars 8 are pre-embedded with the end portions reserved when the waist beam connecting tie steel bars 9 are pre-embedded, thereby changing the anchoring object of the waist beam 6, solving the problem that the smooth supporting piles 2 adjacent to the waist beam 6 are not suitable for roughening and anchoring and cannot be used as anchoring objects, ensuring that the position of the waist beam 6 remains unchanged during the construction process, reducing component damage, and meeting the overall force problem in the use stage.

[0042] In specific implementation, the first prestressed anchor cable 4 installed in the construction method of the present invention is made of 3*15Φ2mm steel strands, the standard value of the axial tension of the first prestressed anchor cable 4 is 300KN, the locking force is 250KN, the length is L=20m@1.4m, the free section of the first prestressed anchor cable 4 is 7m, and the anchoring section of the first prestressed anchor cable 4 is 13m. The second prestressed anchor cable 7 installed is made of 3*15Φ2mm steel strands, the standard value of the axial tension of the second prestressed anchor cable 7 is 300KN, the locking force is 250KN, the length is 16m@2.8m, the free section of the second prestressed anchor cable 7 is 5m, and the anchoring section of the second prestressed anchor cable 7 is 11m.

[0043] When the embodiment of the present invention is implemented, one end of the crown beam connecting tie steel bar 8 is bent to form a first hook 81, and the first hook 81 at one end of the crown beam connecting tie steel bar 8 hooks the crown beam main reinforcement 51 inside the crown beam 5, and the bending angle of the first hook 81 is 85-90°. One end of the waist beam connecting tie steel bar 9 is bent to form a second hook 91, and the second hook 91 at one end of the waist beam connecting tie steel bar 9 hooks the waist beam horizontal reinforcement 61 inside the waist beam 6. The bending angle of the second hook 91 is 85-90°. The crown beam connecting tie steel bar 8 and the waist beam connecting tie steel bar 9 both use threaded steel bars with a diameter of 12 mm, and the spacing of the threaded steel bars is 1.4 m. The first hook 81 of the crown beam connecting tie steel bar 8 is anchored into the crown beam 5 to a depth of 40 cm, and the second hook 91 of the waist beam connecting tie steel bar 9 is anchored into the waist beam 6 to a depth of 40 cm.

[0044] The diameter of each smooth supporting pile 2 is 1000-1200 mm, the distance between two adjacent smooth supporting piles 2 is 1400-1600 mm, the crown beam 5 is arranged on the top of the smooth supporting pile 2 , and the waist beam 6 is arranged at a vertical distance of 2.1 m below the crown beam 5 .

[0045] The smooth supporting pile 2 described in step 2) of the present invention adopts the pre-formed hole non-squeezing soil drilling and pipe pile method for continuous construction operation. The pile end of the smooth supporting pile 2 can be embedded into the medium-weathered muddy siltstone. A support plate 22 is fixed radially inside the top of the smooth supporting pile 2. The support plate 22 is made of 3mm circular steel plate. A plurality of connecting main bars 21 are fixed above the support plate 22 by filling concrete. The connecting main bars 21 are evenly arranged in a circle around the inner wall of the smooth supporting pile 2 and are connected into one body by supporting stirrups 23. The smooth supporting pile 2 is filled with concrete and connected to the crown beam 5 as a whole. One end of each connecting main bar 21 is a right-angle bend section, and the other end is a vertical section. The connecting main bar 21 is anchored into the crown beam 5 through the right-angle bend, and the connecting main bar 21 is vertically toward the pile wall of the smooth supporting pile 2 through the vertical section.

[0046] When the present invention is implemented specifically, in step 3), after the end of the pre-embedded crown beam connecting tie steel bar 8 is reserved, the crown beam 5 template is installed on the side of the crown beam main reinforcement 51, and the crown beam 5 concrete is poured. After the concrete solidifies, the crown beam 5 template is removed.

[0047] When the present invention is implemented specifically, in step 6), the horizontal steel bars 61 of the waist beam are distributed at equal intervals on the waist beam 6, and a waist beam steel bar cage 62 is embedded on the edge of the waist beam 6. The waist beam steel bar cage 62 is composed of waist beam stirrups tied to the outside of the horizontal steel bars 61 of the waist beam. The waist beam stirrups are wrapped around the outside of the horizontal steel bars 61 of the waist beam to provide partial shear resistance for the waist beam 6.

[0048] Compared with the prior art, the technical solution disclosed in the above embodiment has the following beneficial effects:

[0049] In the above embodiment, the construction method of the present invention pre-buries the crown beam connecting tie steel bars 8 in the crown beam 5, and pre-buries the waist beam connecting tie steel bars 9 in the waist beam 6, and welds the end portion reserved when the crown beam connecting tie steel bars 8 are pre-buried with the end portion reserved when the waist beam connecting tie steel bars 9 are pre-buried, so that a reliable connection is formed between the crown beam connecting tie steel bars 8 and the crown beam 5, and between the waist beam connecting tie steel bars 9 and the waist beam 6, ensuring that no displacement occurs during the concrete pouring process, so that the waist beam 6 is subjected to gravity, the tension provided by the vertical tie steel bars, the prestress of the second prestressed anchor cable 7, and the reaction force of the supporting piles on the waist beam 6, forming a force balance, changing the unbalanced force state of the waist beam 6, and enabling the waist beam 6 to better play the role of the foundation pit 1 support system. The construction method of the present invention can enhance the stability of the waist beam 6, make full use of temporary construction facilities, effectively reduce construction costs such as planting reinforcement and roughening, and create a technologically advanced and economical construction process. Compared with the traditional construction method of roughening the pile body and planting reinforcement as the reinforcement anchoring object, the construction method of the present invention can avoid the prestressing of the smooth supporting pile 2 from being destroyed and failing, and is simple to operate, safe and reliable, and is an advanced and safe construction technology.

[0050] The above description has been a detailed description of the present invention. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present application. That is, all equivalent changes and modifications made within the scope of the present application should still fall within the scope of the present invention.

Claims

1. A method for stabilizing the waist beam based on smooth supporting piles, characterized in that: The construction method includes the following processes: Step 1) Measurement and positioning; Step 2) Construction of support piles, water-stop piles and first-layer earthwork excavation: Use a large-diameter drill-and-drill rig to construct a number of vertically parallel smooth support piles around the foundation pit. The diameter of each smooth support pile is 1000-1200mm, and the distance between two adjacent smooth support piles is 1400-1600mm. Step 3) Construction of the crown beam, crown beam connecting tie steel bars and the first prestressed anchor cable: The crown beam is set at the top of the smooth support pile, and the crown beam groove is dug out at the top of the smooth support pile using an excavator. The connecting main bars are implanted in the smooth support pile, and the crown beam main bars are tied in the crown beam groove. The crown beam main bars are welded to the connecting main bars of the smooth support pile, and the crown beam connecting tie steel bars are pre-embedded in the crown beam groove. When the crown beam connecting tie steel bars are pre-embedded in the crown beam groove, the ends are reserved. The first prestressed anchor cable is constructed and installed on the crown beam between two adjacent smooth support piles; Step 4) Excavation of the second layer of earthwork; Step 5) Construction of waist beam, waist beam tie steel bars and second prestressed anchor cable: The waist beam is set at a vertical distance of 2.1m below the crown beam, and the waist beam horizontal steel bars are tied at the preset depth of the foundation pit near the smooth support piles. The waist beam tie steel bars are embedded in the waist beam, and the ends are reserved when embedding the waist beam tie steel bars. The waist beam template is installed, and the waist beam concrete is poured. The second prestressed anchor cable is constructed and installed at the waist beam position between two adjacent smooth support piles; Step 6) Construction of fixing the connecting tie steel bars: weld and fix the end portion reserved when the crown beam connecting tie steel bars are pre-buried and the end portion reserved when the waist beam connecting tie steel bars are pre-buried, one end of the crown beam connecting tie steel bars is bent to form a first hook, the first hook at one end of the crown beam connecting tie steel bars hooks the crown beam main reinforcement inside the crown beam, one end of the waist beam connecting tie steel bars is bent to form a second hook, the second hook at one end of the waist beam connecting tie steel bars hooks the waist beam horizontal reinforcement inside the waist beam, the first hook of the crown beam connecting tie steel bars is anchored into the crown beam to a depth of 40 cm, and the second hook of the waist beam connecting tie steel bars is anchored into the waist beam to a depth of 40 cm.

2. The method for stabilizing the waist beam based on smooth supporting piles according to claim 1 is characterized in that: The smooth support piles described in step 2) are continuously constructed by using the pre-hole non-squeezing soil drilling and pipe pile method, and the pile ends of the smooth support piles can be embedded in the medium-weathered muddy siltstone.

3. The method for stabilizing the waist beam based on smooth supporting piles according to claim 1 is characterized in that: A support plate is fixed radially inside the top of the smooth supporting pile in step 2), and a plurality of connecting main bars are fixed above the support plate by core-filling concrete. The connecting main bars are evenly arranged in a circle around the inner wall of the smooth supporting pile and connected into one body by supporting stirrups. Concrete is poured into the core of the smooth supporting pile to form a whole with the crown beam. One end of each connecting main bar is a right-angle bend section and the other end is a vertical section. The connecting main bar is anchored into the crown beam through the right-angle bend, and the connecting main bar is vertically toward the pile wall of the smooth supporting pile through the vertical section.

4. The method for stabilizing the waist beam based on smooth supporting piles according to claim 1 is characterized in that: In step 3), after leaving the ends of the pre-embedded crown beam connecting reinforcement, the crown beam formwork is installed on the side of the crown beam main reinforcement, and the crown beam concrete is poured. After the concrete solidifies, the crown beam formwork is removed.

5. The method for stabilizing the waist beam based on smooth supporting piles according to claim 1 is characterized in that: In step 6), the horizontal steel bars of the waist beam are evenly spaced on the waist beam, and a waist beam steel bar cage is embedded on the edge of the waist beam. The waist beam steel bar cage is composed of waist beam stirrups tied to the outside of the horizontal steel bars of the waist beam.

Images