Construction method for integral tunnel portal steel ring of shield well

Abstract

The invention provides a construction method of an integral tunnel portal steel ring of a shield well, and relates to the technical field of shield tunnel construction. Comprising the steps of portal steel ring assembly and steel ring reinforcement, portal installation position pretreatment and sliding rail erection, portal steel ring anchoring steel bar pretreatment and steel ring hoisting, portal steel ring anti-floating fixing and gap blocking, portal steel ring steel bar binding and welding, formwork installation and concrete pouring. In the tunnel portal steel ring assembling and steel ring reinforcing step, before the tunnel portal steel ring is hoisted, block steel rings are assembled to form the tunnel portal steel ring according to the true circle parameters of the tunnel portal steel ring, the tunnel portal steel ring is prevented from being deformed due to the influence of external force in the block hoisting process, and meanwhile the interior of the tunnel portal steel ring is reinforced in the radial direction through supporting profile steel. The radial supporting performance of the tunnel portal steel ring is good, the rigidity and the deformation resistance of the tunnel portal steel ring are improved, and therefore the roundness of the tunnel portal steel ring is guaranteed.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of shield tunnel construction, and particularly relates to a construction method of a whole-type steel ring of a shield well portal. BACKGROUND

[0002] In shield tunnel construction, the steel ring of the shield well portal is a core transition component connecting the shield well and the tunnel, and plays a key role in providing positioning and guidance for the shield machine, providing an installation base for the portal sealing device, reinforcing the portal structure, and bearing multiple construction loads, and is directly related to subsequent tunnel construction. Currently, in the industry, the steel ring is usually fabricated in blocks, hoisted into the shield well after positioning, the lower half of the steel ring is installed and the part of the concrete is poured, the upper half of the steel ring is installed and welded with the lower half, and finally the whole concrete is poured to complete the construction. However, in the process of block splicing, hoisting and welding in the prior art, uneven stress is prone to cause deformation, resulting in poor true circularity of the steel ring, and further affecting subsequent tunnel construction.

[0003] Therefore, there is an urgent need for a construction method of a whole-type steel ring of a shield well portal to ensure the true circularity of the steel ring. SUMMARY

[0004] The purpose of the present application is to solve the above problems, and to provide a construction method of a whole-type steel ring of a shield well portal to ensure the true circularity of the steel ring.

[0005] The present application provides a construction method of a whole-type steel ring of a shield well portal, comprising: Step 1, portal steel ring assembly and steel ring reinforcement: according to the true circularity parameters of the portal steel ring, the block steel rings are assembled to form the portal steel ring, and the inside of the portal steel ring is reinforced along the radial direction by using support steel; Step 2, portal installation position pretreatment and slide rail erection: the first ring frame beam of the shield well portal side wall corresponding to the portal steel ring installation area is cut off, the positioning points are marked at the portal steel ring installation position on the underground continuous wall, the waterproof board is laid and constructed, and the slide rail for the portal steel ring to be placed is installed at the bottom of the shield well; Step 3, portal steel ring anchoring steel pretreatment and steel ring hoisting: the anchoring steel at the position corresponding to the slide rail outside the portal steel ring is cut off, the portal steel ring is hoisted and lowered onto the slide rail by using hoisting equipment according to the positioning points, and is translated along the slide rail to the portal steel ring installation position by using a hand-operated hoist; Step 4, portal steel ring anti-floating fixation and gap sealing: the portal steel ring is fixed with the underground continuous wall and the second ring frame beam by using a fixing member, and the gap between the portal steel ring and the underground continuous wall is sealed by using a sealing member; Step 5, portal steel ring steel binding and welding: the steel reinforcement of the portal side wall is bound, and the steel reinforcement is welded with the corresponding half-circle steel ring; Step 6, template installation and concrete pouring: the template installation and concrete pouring are sequentially performed in three layers from bottom to top in the range of the side wall of the portal.

[0006] According to the technical scheme provided by some embodiments of the present application, the assembling of the segmented steel ring into the portal steel ring according to the true circle parameters of the portal steel ring comprises: transporting the segmented steel ring to the construction site for assembling, and obtaining the portal steel ring after detecting that the center and size of the portal steel ring meet the true circle parameters.

[0007] According to the technical scheme provided by some embodiments of the present application, the radial reinforcement of the interior of the portal steel ring by the support steel comprises: reinforcing the interior of the portal steel ring by H-shaped support steel, which is uniformly distributed along the radial direction in the interior of the portal steel ring, and is connected to each other at one end of the H-shaped support steel gathered at the center of the portal steel ring, and is fixedly connected to the inner wall of the portal steel ring at the other end.

[0008] According to the technical scheme provided by some embodiments of the present application, the first ring frame beam corresponding to the installation area of the portal steel ring of the portal side wall of the shield well is cut off, the installation position of the portal steel ring on the underground continuous wall is marked, the waterproof board is laid, and the slide rail for the translation of the portal steel ring is installed at the bottom of the shield well: Step 2.1, cutting off a plurality of first ring frame beams in the installation position of the portal steel ring in the range of the portal side wall in the shield well; Step 2.2, marking the center point of the installation position of the portal steel ring on the underground continuous wall, calculating the positions of the portal steel ring up, down, left and right from the center point, and marking the positions on the underground continuous wall; Step 2.3, laying a waterproof board on the underground continuous wall outside the portal steel ring; Step 2.4, installing a slide rail at the bottom of the shield well below the positioning point of the installation position of the portal steel ring, and adjusting the top elevation of the slide rail to adapt to the design elevation of the bottom of the portal steel ring, and the length of the slide rail covers the translation path of the portal steel ring from the hoisting position to the installation position.

[0009] According to the technical scheme provided by some embodiments of the present application, the hoisting of the portal steel ring onto the slide rail according to the positioning point by the hoisting equipment comprises: The main hoist and the auxiliary hoist are connected to the hoisting points of the portal steel ring by the lifting devices, the portal steel ring is hoisted to a specified height, the main hoist and the auxiliary hoist are kept at a constant hoisting radius, the auxiliary hoist is separated from the hoisting points of the portal steel ring after the portal steel ring is straightened. The main hoist hoists the portal steel ring onto the slide rail at the bottom of the shield well according to the positioning point.

[0010] According to the technical scheme provided by some embodiments of the present application, the step of translating the hand chain hoist to the installation position along the slide rail comprises: The hand chain hoist installed on the hole portal steel ring is connected with the hoisting ring pre-buried on the underground continuous wall, the hoisting device on the side of the hole portal steel ring close to the underground continuous wall is disconnected from the main hoist and switched to be connected with the hand chain hoist on the second ring frame beam on the top of the hole portal steel ring; The hole portal steel ring is translated along the slide rail to the side close to the underground continuous wall by the hand chain hoist installed on the hole portal steel ring, the main hoist and the hand chain hoist on the second ring frame beam on the top of the hole portal steel ring, and is translated to the installation position. After the steel ring is positioned, the hoisting device on the side of the hole portal steel ring away from the underground continuous wall is disconnected from the main hoist and switched to be connected with the hand chain hoist on the second ring frame beam on the top of the hole portal steel ring.

[0011] According to the technical scheme provided by some embodiments of the present application, the step of fixing the hole portal steel ring to the underground continuous wall and the second ring frame beam by the fixing member comprises: After the steel ring is positioned, the hole portal steel ring is fixed in the direction perpendicular to the underground continuous wall by implanting steel bars on the underground continuous wall above the steel ring. The H-shaped counter-tying steel is installed between the top of the hole portal steel ring and the second ring frame beam on the top of the hole portal steel ring, and the hole portal steel ring is fixed in the direction parallel to the underground continuous wall.

[0012] According to the technical scheme provided by some embodiments of the present application, the step of binding the hole portal side wall steel bars and welding the steel bars to the corresponding semicircular steel ring comprises: The inner row steel bars are bound on the side of the hole portal side wall close to the underground continuous wall, and the inner row steel bars are welded to the hole portal steel ring and the anchoring steel bars on the hole portal steel ring. The outer row steel bars are bound on the side of the hole portal side wall away from the bottom surface of the underground continuous wall, and the outer row steel bars are welded to the hole portal steel ring and the anchoring steel bars on the hole portal steel ring. The inner row steel bars and the outer row steel bars are fixed by the tie bars.

[0013] According to the technical scheme provided by some embodiments of the present application, before step 6, the method further comprises: inserting a steel pipe at a predetermined position between the hole portal side wall steel bars, welding a water stop ring on the outer top and bottom sides of the steel pipe, and filling grease in the steel pipe.

[0014] According to the technical scheme provided by some embodiments of the present application, the step of sequentially installing the formwork and pouring the concrete in three layers from bottom to top within the range of the hole portal side wall comprises: Step 6.1, remove the sliding rail, install the first layer of formwork, secondary beam, main beam and throwing support in sequence on the outside of the side wall of the hole portal in the first layer of concrete pouring height range, and use the water stop pull rod to pull the main beam and the ground continuous wall planting steel bar; open the vibrating hole on the first layer of formwork; pour and vibrate the concrete between the ground continuous wall outside the hole portal steel ring and the first layer of formwork from the first layer of formwork top gap, and block the vibrating hole when pouring to the vibrating hole position; Step 6.2, remove the hand chain block, install the second layer of formwork, secondary beam and main beam in sequence on the outside of the side wall of the hole portal in the second layer of concrete pouring height range, and use the water stop pull rod to pull the main beam and the ground continuous wall planting steel bar, and pour the concrete between the ground continuous wall outside the hole portal steel ring and the second layer of formwork from the second layer of formwork top gap; Step 6.3, install the third layer of formwork, secondary beam and main beam in sequence on the outside of the side wall of the hole portal in the third layer of concrete pouring height range, and use the water stop pull rod to pull the main beam and the ground continuous wall planting steel bar, pour the concrete between the ground continuous wall outside the hole portal steel ring and the third layer of formwork through the reserved hole on the second ring frame beam on the top of the hole portal steel ring, vibrate the concrete through the reserved hole, and block the reserved hole after vibrating.

[0015] Compared with the prior art, the construction method of the shield well integral hole portal steel ring has the beneficial effects that: the construction method of the shield well integral hole portal steel ring of the application comprises hole portal steel ring assembly and steel ring reinforcement, hole portal installation position pretreatment and sliding rail erection, hole portal steel ring anchoring steel bar pretreatment and steel ring hoisting, hole portal steel ring anti-floating fixation and gap sealing, hole portal steel ring steel bar binding and welding, and formwork installation and concrete pouring; in the hole portal steel ring assembly and steel ring reinforcement step, the segmented steel ring is assembled to form the hole portal steel ring according to the true circle parameters of the hole portal steel ring before hoisting, so that the deformation of the hole portal steel ring caused by external force during segmented hoisting is avoided, the true circularity of the hole portal steel ring is affected, at the same time, the inside of the hole portal steel ring is reinforced along the radial direction by using support steel, so that the radial support of the hole portal steel ring is good, the self stiffness and anti-deformation ability of the hole portal steel ring are improved, and the true circularity of the hole portal steel ring is ensured.

[0016] It should be understood that the description of technical features, technical solutions, advantages or similar language in the present application does not imply that all features and advantages can be realized in any single embodiment. On the contrary, it can be understood that the description of a feature or advantage means that the specific technical feature, technical solution or advantage is included in at least one embodiment. Therefore, the description of technical features, technical solutions or advantages in the specification does not necessarily refer to the same embodiment. Further, the technical features, technical solutions and advantages described in the embodiments can be combined in any appropriate manner. Those skilled in the art will understand that the embodiments can be implemented without one or more specific technical features, technical solutions or advantages of the specific embodiments. In other embodiments, additional technical features and advantages can be identified in specific embodiments that do not embody all embodiments. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings from these drawings without creative labor.

[0018] Figure 1 The construction process schematic diagram of the construction method of the whole type tunnel portal steel ring of the shield well provided by the embodiment of the present application; Figure 2 The construction process schematic diagram of step 2, the portal installation position pretreatment and the slide rail erection provided by the embodiment of the present application; Figure 3 The construction process schematic diagram of step 6, the template installation and the concrete pouring provided by the embodiment of the present application; Figure 4 The structure schematic diagram of the segmented steel ring after assembly in step 1 provided by the embodiment of the present application; Figure 5 The structure schematic diagram of the portal steel ring after reinforcement in step 1 provided by the embodiment of the present application; Figure 6 The height schematic diagram of the first ring frame beam, the second ring frame beam, the steel pipe, the slide rail position and the concrete pouring position provided by the embodiment of the present application; Figure 7 The schematic diagram of the portal steel ring hoisting and lowering position in step 3 provided by the embodiment of the present application; Figure 8 The schematic diagram of the portal steel ring translation and positioning in step 3 provided by the embodiment of the present application; Figure 9 The schematic diagram of the counter-pressing type steel position of the installation piece in step 4 provided by the embodiment of the present application; Figure 10 A hole door steel ring reinforcing position schematic diagram of step 5 provided for the embodiment of the present application; Figure 11 A hole door steel ring anchoring steel bar cutting position and a hole door steel ring hand chain block installation position schematic diagram of step 3 provided for the embodiment of the present application.

[0019] The text annotations in the figure represent: 1, block steel ring; 2, anchoring steel bar; 3, angle steel; 4, reinforcing steel; 5, supporting steel; 6, first ring frame beam; 7, steel pipe; 8, second ring frame beam; 9, sliding rail; 10, counter steel. DETAILED DESCRIPTION

[0020] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings, and the description in this part is only exemplary and explanatory, and should not have any limiting effect on the protection scope of the present application. Specifically, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0021] It should be noted that similar labels and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0022] As mentioned in the background, in order to solve the problems in the prior art, the present embodiment provides a construction method of a whole hole door steel ring of a shield well, comprising: Step 1, hole door steel ring assembly and steel ring reinforcement: according to the true circle parameters of the hole door steel ring, the block steel ring 1 is assembled to form the hole door steel ring, and the supporting steel 5 is used to reinforce the inside of the hole door steel ring along the radial direction; Specifically, as shown in Figure 1 and Figure 4 The inner diameter of the hole door steel ring in the present embodiment is 15600mm; it is divided into 4 blocks and transported to the site, Figure 4The middle dotted line is the boundary line of the adjacent sub-block steel ring 1, and the part between the dotted lines represents a sub-block steel ring 1. The inner side of each sub-block steel ring 1 is connected to three L100x100x10 reinforcing angle steels 3 arranged in the shape of a claw. The other end of the three reinforcing angle steels 3 is connected to one reinforcing steel 4, which is used to reinforce the sub-block steel ring 1. The outer side of each sub-block steel ring 1 is provided with anchor steel bars 2 with a diameter of 12 mm and anchor steel bars 2 with a diameter of 16 mm. The sub-block steel rings 1 are assembled to form the hole portal steel ring according to the true circle parameters of the hole portal steel ring. The outer side of the connection part of each sub-block steel ring 1 is connected by bolts, and the inner side is welded by welding rods. The inside of the hole portal steel ring is reinforced along the radial direction by supporting steel 5. On the one hand, the true circularity of the hole portal steel ring before the subsequent construction steps is ensured, and the deformation of the hole portal steel ring caused by external force during the sub-block hoisting process is avoided. On the other hand, the radial support of the hole portal steel ring is good, which improves the stiffness and anti-deformation ability of the hole portal steel ring, thereby further ensuring the true circularity of the hole portal steel ring.

[0023] Step 2, hole portal installation position pretreatment and slide rail erection The first ring frame beam 6 corresponding to the hole portal steel ring installation area of the side wall of the shield well is cut off, the positioning point of the hole portal steel ring installation position on the underground continuous wall is marked, the waterproof board is laid, and the slide rail 9 for the translation of the hole portal steel ring is installed at the bottom of the shield well. Specifically, as shown in Figure 1 and Figure 6 , the first ring frame beam 6 corresponding to the hole portal steel ring installation area of the side wall of the shield well is cut off, which is to remove the structural obstacles at the hole portal steel ring installation position, to ensure that the hole portal steel ring has the installation space required by the design during subsequent construction, to avoid interference of the first ring frame beam 6, to make the hole portal steel ring unable to be positioned, and to lay a foundation for subsequent construction. The positioning point marking construction of the hole portal steel ring installation position provides a position basis for subsequent hole portal steel ring construction, to ensure the accuracy of the hole portal steel ring installation position. The waterproof board is laid on the underground continuous wall, which is to prevent underground water from entering the inside of the shield well and affecting subsequent construction. The slide rail 9 for the translation of the hole portal steel ring is installed at the bottom of the shield well, which is used to support the hole portal steel ring and avoid direct contact of the hole portal steel ring with the rough ground at the bottom of the shield well. At the same time, the direction of the slide rail 9 is consistent with the translation path of the hole portal steel ring, which can provide a guide for the translation of the hole portal steel ring and ensure that the hole portal steel ring can be accurately moved to the positioning point marked on the underground continuous wall.

[0024] Step 3, hole portal steel ring anchor steel pretreatment and steel ring hoisting: cutting off the anchor steel 2 corresponding to the position of the slide rail 9 on the outer side of the hole portal steel ring, hoisting the hole portal steel ring down to the slide rail 9 according to the positioning point by using hoisting equipment, and translating the hole portal steel ring to the hole portal steel ring installation position along the slide rail 9 by using a hand-operated hoist. Specifically, as shown in Figure 1 and Figure 11As shown, if the preset anchor steel bars 2 outside the steel ring are in the corresponding position of the sliding rail 9, they will form an obstacle with the top surface of the sliding rail 9 when the steel ring is lowered, resulting in the steel ring not being able to be placed stably on the sliding rail 9. Therefore, the anchor steel bars 2 in the range A corresponding to the position of the sliding rail 9 outside the steel ring need to be cut off, so that the bottom of the steel ring is in full contact with the top surface of the sliding rail 9, ensuring that the steel ring is evenly stressed after being lowered, and avoiding the steel ring from being tilted due to partial suspension. The range A is Figure 11 In addition, the steel ring needs to be translated along the sliding rail 9 to the installation position, and the anchor steel bars 2 in the corresponding position are cut off, which can avoid scratching between the steel bars and the sliding rail 9 during translation, ensuring smooth movement of the steel ring. As shown in Figure 7 and Figure 8 shown, the steel ring is lowered and placed on the sliding rail 9 by hoisting equipment according to the positioning points, and is translated along the sliding rail 9 to the installation position of the steel ring by a chain block, so as to ensure the accuracy of the installation position of the steel ring and lay a foundation for subsequent construction steps. In addition, butter can be applied on the sliding rail 9 before the steel ring is hoisted to the bottom of the shield well, which can reduce the frictional resistance between the steel ring and the sliding rail 9, so that the chain block can drive the steel ring to move more smoothly. The chain block is a light manual lifting equipment, which includes a chain, a gear mechanism and a hook, and relies on pulling the chain to drive the gear to move the weight hung on the hook.

[0025] Step 4, anti-floating fixation of the steel ring and gap sealing: the steel ring is fixed to the underground continuous wall and the second ring frame beam 8 by a fixing member, and a sealing member is used to seal the gap between the steel ring and the underground continuous wall; Specifically, as shown in Figure 1 and Figure 9 shown, the fixing member includes steel bars and a pair of top steel 10, the steel bars are used to fix the steel ring in a direction perpendicular to the underground continuous wall, and the pair of top steel 10 is used to fix the steel ring in a direction parallel to the underground continuous wall, both of which are used to prevent the steel ring from floating in the direction parallel to the underground continuous wall. In this embodiment, the sealing member can be a 5mm thick iron sheet, which is used to seal the gap between the steel ring and the underground continuous wall, so as to avoid the concrete from entering the inside of the steel ring through the gap and polluting the steel ring during pouring.

[0026] Step 5, steel bar binding and welding of the steel ring: steel bars of the side wall are bound, and the steel bars are welded to the corresponding semicircular steel ring; Specifically, as shown in Figure 1 and Figure 10As shown, the hole door side wall reinforcement is bound and welded with the corresponding semicircular steel ring to realize the fixation of the hole door steel ring and the side wall reinforcement, fix the hole door steel ring in the installation position, and avoid the influence of the hole door ring position deviation on the hole door forming quality in subsequent construction. In addition, the inner row reinforcement and the outer row reinforcement will be bonded with the subsequently poured concrete, improving the overall strength and deformation resistance of the structure.

[0027] Step 6, template installation and concrete pouring: template installation and concrete pouring are sequentially performed in three layers from bottom to top within the hole door side wall range.

[0028] Specifically, as shown in Figure 1 , Figure 3 and Figure 6 , template installation and concrete pouring are sequentially performed in three layers from bottom to top within the hole door side wall range, and layered pouring can reduce the pouring difficulty, facilitate the vibration of the concrete, and improve the compactness of the concrete.

[0029] The construction method of the shield well integral hole door steel ring of the application comprises hole door steel ring assembly and steel ring reinforcement, hole door installation position pretreatment and slide rail erection, hole door steel ring anchoring reinforcement pretreatment and steel ring hoisting, hole door steel ring anti-floating fixation and gap plugging, hole door steel ring reinforcement binding and welding, and template installation and concrete pouring. In the hole door steel ring assembly and steel ring reinforcement step, the segmented steel ring is assembled to form the hole door steel ring according to the true circle parameters of the hole door steel ring before hoisting, avoiding deformation of the hole door steel ring caused by external force during segmented hoisting, and the inside of the hole door steel ring is reinforced along the radial direction by using support steel, so that the radial support of the hole door steel ring is good, the stiffness and deformation resistance of the hole door steel ring are improved, and the true circularity of the hole door steel ring is ensured.

[0030] In a preferred embodiment, the segmented steel ring 1 is assembled to form the hole door steel ring according to the true circle parameters of the hole door steel ring, which comprises: transporting the segmented steel ring 1 to the construction site for assembly, and obtaining the hole door steel ring after detecting that the center and size of the hole door steel ring meet the true circle parameters.

[0031] Specifically, as shown in Figure 1 and Figure 4 , the segmented steel ring 1 is transported to the construction site for assembly, and whether the center and size of the hole door steel ring meet the true circle parameters is detected to ensure that the true circularity of the hole door steel ring meets the requirements before subsequent construction, until the true circle parameters are qualified, and the hole door steel ring is obtained, providing protection for subsequent construction steps.

[0032] In a preferred embodiment, the reinforcing the inside of the steel ring of the portal by the support steel 5 in the radial direction comprises: reinforcing the inside of the steel ring of the portal by H-shaped support steel 5, which is evenly distributed in the radial direction inside the steel ring of the portal, and is connected to each other at one end of the circle center of the steel ring of the portal, and is fixedly connected to the inner wall of the steel ring of the portal at the other end.

[0033] Specifically, as shown in Figure 1 and Figure 5 , in this embodiment, 8 H200x200 type support steels 5 are used to reinforce the inside of the steel ring of the portal, which are evenly distributed in the radial direction in the form of a rice character inside the steel ring of the portal, and are connected to each other at one end of the circle center of the steel ring of the portal, and are fixedly connected to the inner wall of the steel ring of the portal at the other end. The connection between the support steels 5 and the inner wall of the steel ring of the portal is by welding. In this embodiment, 8 H-shaped support steels 5 are evenly distributed in the radial direction in the form of a rice character, but can be adjusted according to the site construction conditions, and are not limited to 8 H-shaped support steels 5 and not limited to the rice character distribution mode.

[0034] In a preferred embodiment, the first ring frame beam 6 corresponding to the installation area of the steel ring of the portal of the shield well is cut off, the installation position of the steel ring of the portal is marked on the underground continuous wall, the waterproof board is laid, and the slide rail 9 for the translation of the steel ring of the portal is installed at the bottom of the shield well. It comprises: Step 2.1, cutting off the first ring frame beam 6 corresponding to the installation position of the steel ring of the portal in the range of the portal side wall of the shield well; Step 2.2, marking the center point of the installation position of the steel ring of the portal on the underground continuous wall, calculating the position of the steel ring of the portal up and down and left and right from the center point, and marking on the underground continuous wall; Step 2.3, laying a waterproof board on the underground continuous wall outside the steel ring of the portal; Step 2.4, installing a slide rail 9 at the bottom of the shield well below the installation position of the steel ring of the portal, and adjusting the top elevation of the slide rail 9 to adapt to the design elevation of the bottom of the steel ring of the portal, and the length of the slide rail 9 covers the translation path of the steel ring of the portal from the hoisting position to the installation position.

[0035] Specifically, as shown in Figure 1 , Figure 2 and Figure 6 , 3 first ring frame beams 6 corresponding to the installation position of the steel ring of the portal in the range of the portal side wall of the shield well are cut off, and the installation position of the steel ring of the portal is provided.

[0036] Mark the center point of the steel ring installation position on the underground continuous wall, and mark the up, down, left and right positions of the steel ring on the underground continuous wall according to the center point, so as to facilitate positioning when the steel ring is installed; in addition, in order to prevent the shield from being tilted when starting, the center point of the steel ring installation position is lifted by 30mm higher than the design elevation when marked.

[0037] Lay EVA waterproof board on the underground continuous wall outside the steel ring installation position to prevent groundwater from entering the inside of the shield well and affecting subsequent construction.

[0038] A slide rail 9 is installed at the bottom of the shield well below the positioning point of the steel ring installation position, which is welded by H200 steel and used to translate the steel ring along the slide rail 9, and adjust the top elevation of the slide rail 9 to adapt to the design elevation of the bottom of the steel ring. The length of the slide rail 9 covers the translation path of the steel ring from the hoisting position to the installation position. In this embodiment, the height of the slide rail 9 is 981mm, the center distance between the slide rails 9 is 5060mm, the longitudinal distance between the slide rails 9 is 300mm, and a total of 2 rows of 8 slide rails 9 are arranged, but the parameters can be adjusted according to the construction requirements.

[0039] In a preferred embodiment, hoisting the steel ring down to the slide rail according to the positioning point by using hoisting equipment includes: Connecting the main crane and the auxiliary crane to the lifting points of the steel ring through the lifting tools, first lifting the steel ring to the specified height synchronously, keeping the lifting radius of the main crane and the auxiliary crane unchanged, moving the steel ring until it stands up, and then separating the auxiliary crane from the lifting points of the steel ring. Hoisting the steel ring to the slide rail at the bottom of the shield well by using the main crane according to the positioning point.

[0040] Specifically, as Figure 1 and Figure 7As shown, in the present embodiment, the hoisting of the steel ring of the portal is carried out by using a 150T automobile crane as a main hoist and a 75T crawler crane as an auxiliary hoist for double-machine lifting. Through double-machine trial hoisting, it is checked whether the lifting appliance and lifting point are safe and reliable after the steel ring of the portal is lifted by 30 cm, and after confirming that it is normal, the steel ring of the portal is loaded onto a long trailer and pulled to a designated area near the shield well. The lifting appliance is generally a steel wire rope, the main hoist and the auxiliary hoist are connected to the lifting points on both sides of the steel ring of the portal through the steel wire rope, the hoisting radius of the 150T automobile crane is 12 m in the initial hoisting stage, the hoisting radius of the 75T crawler crane is 8 m, after the double machines are lifted to a certain height, the 150T automobile crane hooks the lifting rod, the 75T crawler crane falls the hook, and they walk forward at the same time to keep the hoisting radius unchanged, and the load rate of the main hoist and the auxiliary hoist is controlled to be not more than 80%, until the steel ring of the portal is straightened, and the auxiliary hoist is separated from the lifting point of the steel ring of the portal. The selection of the main hoist and the auxiliary hoist, the hoisting radius, and the load rate of the main hoist and the auxiliary hoist can be adjusted according to the weight and size of the lifting ring and the actual situation on site, and are not limited to the above parameters. According to the positioning point, the main hoist is used to hoist the steel ring of the portal to the slide rail 9 at the bottom of the shield well, so that the steel ring of the portal can be matched and installed when it is lowered, laying a foundation for subsequent translation and positioning. At the same time, the slide rail 9 can provide stable support to avoid deformation of the steel ring of the portal due to rough contact with the ground or uneven stress.

[0041] In a preferred embodiment, the translation along the slide rail 9 to the installation position by the hoist comprises: connecting the lifting appliance on the steel ring of the portal to the hoist ring pre-buried on the underground continuous wall, disconnecting the lifting appliance on the side of the steel ring of the portal close to the underground continuous wall from the main hoist and switching to connection with the hoist on the second ring frame beam 8 at the top of the steel ring of the portal; translating the steel ring of the portal along the slide rail 9 to the side close to the underground continuous wall by the hoist installed on the steel ring of the portal, the main hoist and the hoist on the second ring frame beam 8 at the top of the steel ring of the portal, and translating to the installation position; after the steel ring is in place, disconnecting the lifting appliance on the side of the steel ring of the portal away from the underground continuous wall from the main hoist and switching to connection with the hoist on the second ring frame beam 8 at the top of the steel ring of the portal.

[0042] Specifically, as Figure 7 and Figure 11As shown, in this embodiment, three hand-operated hoists with a rated lifting capacity of 10 tons are installed on the lower half of the hole portal steel ring and connected with the lifting rings pre-buried on the underground continuous wall. The steel wire ropes on the side of the hole portal steel ring close to the underground continuous wall are disconnected from the main hoist, and the corresponding lifting points on the hole portal steel ring are connected with two hand-operated hoists with a rated lifting capacity of 10 tons on the second ring frame beam 8 at the top of the underground continuous wall. The hole portal steel ring is translated along the slide rail to the installation position by the three hand-operated hoists installed on the hole portal steel ring, the main hoist, and the two hand-operated hoists on the second ring frame beam 8 at the top of the hole portal steel ring. As shown in Figure 8 As shown, after the steel ring is in place, the steel wire ropes on the side of the hole portal steel ring away from the underground continuous wall are disconnected from the main hoist, and the lifting points at the corresponding positions of the steel wire ropes are connected with two hand-operated hoists with a rated lifting capacity of 10 tons on the second ring frame beam 8 at the top of the hole portal steel ring. The model and number of the hand-operated hoists can be selected according to actual needs, and are not limited to the above parameters.

[0043] In a preferred embodiment, the fixing of the hole portal steel ring to the underground continuous wall and the second ring frame beam 8 by the fixing member includes: fixing the hole portal steel ring to the underground continuous wall in a direction perpendicular to the underground continuous wall by embedding steel bars into the underground continuous wall through the pre-set embedding holes on the hole portal steel ring; fixing the hole portal steel ring to the underground continuous wall in a direction parallel to the underground continuous wall by installing H-shaped butt-joint steel 10 between the top of the hole portal steel ring and the second ring frame beam 8 at the top of the hole portal steel ring.

[0044] Specifically, as shown in Figure 1 and Figure 9 fixing the hole portal steel ring to the underground continuous wall in a direction perpendicular to the underground continuous wall by embedding steel bars into the underground continuous wall through the embedding holes arranged circumferentially on the hole portal steel ring, and fixing the hole portal steel ring to the underground continuous wall in a direction parallel to the underground continuous wall by installing three H300-shaped butt-joint steels 10 with a length of 470 mm between the top of the hole portal steel ring and the second ring frame beam 8 at the top of the hole portal steel ring, all to prevent the hole portal steel ring from floating in a direction parallel to the underground continuous wall.

[0045] In a preferred embodiment, the hole portal side wall steel bar binding and welding of the steel bars to the corresponding half-circle steel ring include: binding the inner row steel bars on the side of the hole portal side wall close to the underground continuous wall and welding the inner row steel bars to the hole portal steel ring and the anchoring steel bars 2 on the hole portal steel ring; binding the outer row steel bars on the side of the hole portal side wall away from the bottom surface of the underground continuous wall and welding the outer row steel bars to the hole portal steel ring and the anchoring steel bars 2 on the hole portal steel ring; fixing the inner row steel bars to the outer row steel bars by tie bars.

[0046] Specifically, as shown inFigure 1 and Figure 10 As shown, the inner row of distribution reinforcement bars and the inner row of main reinforcement bars are tied together on the side wall of the tunnel portal, close to the diaphragm wall, to form the inner row of reinforcement bars. Following the order from the bottom to the top of the diaphragm wall, one inner row of main reinforcement bars is welded to the tunnel portal steel ring every 30 cm, with a weld length 10 times the diameter of the main reinforcement bars. The outer row of distribution reinforcement bars and the outer row of main reinforcement bars are tied together on the side wall of the tunnel portal, away from the diaphragm wall, to form the outer row of reinforcement bars. Following the order from the bottom to the top of the diaphragm wall, one outer row of main reinforcement bars is welded to the steel ring every 30 cm, with a weld length 10 times the diameter of the main reinforcement bars. All anchoring reinforcement bars on the tunnel portal steel ring are then welded to the inner and outer row of reinforcement bars.

[0047] By fixing the inner and outer rows of reinforcing bars with tie rods, the inner and outer rows of reinforcing bars are connected into a whole, reducing the displacement or deformation of individual reinforcing bars and ensuring the overall stability of the reinforcing bars.

[0048] In a preferred embodiment, prior to step 6, the method further includes: inserting a steel pipe 7 at a predetermined position between the reinforcing bars of the side wall of the opening, welding water-stop rings on the upper and lower sides of the outside of the steel pipe 7, and filling the inside of the steel pipe 7 with grease.

[0049] Specifically, such as Figure 1 and Figure 6 As shown, steel pipes 7 are inserted at predetermined positions between the reinforcing bars tied to the side wall of the tunnel portal. The steel pipes 7 are used to fill any loose areas with grout after the concrete is poured. Water-stop rings are welded to the outside of the steel pipes 7. The welding positions of the water-stop rings are on the upper and lower sides of the midpoint of the length of the steel pipes 7. The water-stop rings can form a physical barrier in the concrete through their own structure to prevent groundwater from seeping into the shield shaft from the side of the diaphragm wall through gaps, thus avoiding affecting the waterproof performance of the tunnel portal structure. Grease is filled inside the steel pipes 7 to prevent concrete from entering the steel pipes 7, thus ensuring that grouting can be carried out if the steel pipes 7 fail.

[0050] In a preferred embodiment, the step of installing formwork and pouring concrete in three layers from bottom to top within the sidewall area of ​​the portal includes: Step 6.1: Remove the slide rail 9, and install the first layer template, secondary rib, main rib and outrigger in sequence on the outside of the portal sidewall within the first layer concrete pouring height range. Use water-stop tie rods to tie the main rib to the underground continuous wall reinforcement. Open vibration holes on the first layer template. Pour concrete and vibrate it between the underground continuous wall outside the portal steel ring and the first layer template through the gap at the top of the first layer template. Seal the vibration holes when pouring to the position of the vibration holes. Step 6.2, remove the hand chain hoist, and install the second layer of formwork, secondary beam and main beam in turn on the outside of the side wall of the portal within the second layer of concrete pouring height range, and use the water stop pull rod to pull the main beam and the underground continuous wall with the embedded steel bar, and pour the concrete between the underground continuous wall outside the portal steel ring and the second layer of formwork from the gap at the top of the second layer of formwork. Step 6.3, install the third layer of formwork, secondary beam and main beam in turn on the outside of the side wall of the portal within the third layer of concrete pouring height range, and use the water stop pull rod to pull the main beam and the underground continuous wall with the embedded steel bar, and pour the concrete between the underground continuous wall outside the portal steel ring and the third layer of formwork through the reserved hole on the second ring frame beam 8 at the top of the portal steel ring, and vibrate the concrete through the reserved hole, and seal the reserved hole after vibration.

[0051] Specifically, as shown in Figure 1 and Figure 3 and Figure 6 , remove the slide rail 9, install the first layer of formwork, secondary beam, main beam and throw support in turn on the outside of the side wall of the portal within the first layer of concrete pouring height H1, the installation height of the first layer of formwork is the first layer of concrete pouring height H1, and the main beam is pulled with the embedded steel bar of the underground continuous wall with the water stop pull rod, the secondary beam, main beam, throw support and water stop pull rod are used to fix the first layer of formwork, the lateral pressure generated when pouring concrete is dispersed to prevent the first layer of formwork from deforming; in this embodiment, a steel pipe with a diameter of 48 mm is provided as a throw support, and the horizontal spacing of the throw support is 1 m. Eight 150 mm x 150 mm rectangular vibration holes are opened on the first layer of formwork to facilitate the insertion of the vibration rod for vibrating the concrete, and the concrete is poured between the underground continuous wall outside the portal steel ring and the first layer of formwork from the gap at the top of the first layer of formwork and vibrated through the vibration holes, and the vibration holes are sealed with a steel plate when pouring to the vibration hole position.

[0052] After the first layer of concrete is poured, remove the hand chain hoist on the portal steel ring and the hand chain hoist on the second ring frame beam 8 at the top of the portal steel ring, install the second layer of formwork, secondary beam and main beam in turn on the outside of the side wall of the portal within the second layer of concrete pouring height H2, the installation height of the second layer of formwork is the second layer of concrete pouring height H2, and the main beam is pulled with the embedded steel bar of the underground continuous wall with the water stop pull rod, the secondary beam, main beam and water stop pull rod are used to fix the second layer of formwork; pour the concrete between the underground continuous wall outside the portal steel ring and the second layer of formwork from the gap at the top of the second layer of formwork.

[0053] After the second layer of concrete is poured, the third layer of formwork, secondary beams and primary beams are installed in sequence on the outside of the side wall of the portal within the third layer of concrete pouring height H3, the third layer of formwork is installed at the third layer of concrete pouring height H3, and the primary beams are pulled against the ground continuous wall by water stop pull rods, the secondary beams, primary beams and water stop pull rods are used to fix the third layer of formwork; the concrete is poured between the ground continuous wall outside the portal steel ring and the third layer of formwork through 8 reserved holes with a diameter of 150mm on the second ring frame beam 8 at the top of the portal steel ring, the reserved holes should be dredged in advance, the concrete is vibrated through the reserved holes during pouring, and the reserved holes are blocked by steel plates after vibration. In addition, a back-mounted vibrator can be installed outside the third layer of formwork during pouring to facilitate the pouring and compaction of the third layer of concrete.

[0054] In the embodiment, the first layer of formwork, the second layer of formwork and the third layer of formwork are all 15mm thick wooden formwork; the secondary beams are horizontally arranged with 5cm*10cm square wood with a spacing of 20cm; the primary beams are arranged vertically to the secondary beams, the primary beams are double-pinned 140b type channel steel with a spacing of 50cm; and the primary beams are pulled against the ground continuous wall by water stop pull rods with planted reinforcement, the water stop pull rods have a diameter of 20mm, the effective length of the water stop pull rods implanted in the ground continuous wall is not less than 12 times of the diameter, the horizontal spacing of the planted reinforcement is 50cm, and the longitudinal spacing is 60cm. In addition, the water stop structure of the water stop pull rod can block the water seepage channel of the groundwater into the inside of the shield, and guarantee the waterproof performance of the concrete structure.

[0055] The construction method of the shield well integrated portal steel ring of the application comprises portal steel ring assembly and steel ring reinforcement, portal installation position pretreatment and sliding rail erection, portal steel ring anchoring steel bar pretreatment and steel ring hoisting, portal steel ring anti-floating fixation and gap sealing, portal steel ring steel bar binding and welding, and formwork installation and concrete pouring; in the portal steel ring assembly and steel ring reinforcement step, the portal steel ring is assembled to form the portal steel ring according to the true circle parameters of the portal steel ring before hoisting, so as to avoid deformation of the portal steel ring caused by external force during block hoisting, and the inside of the portal steel ring is reinforced along the radial direction by using support steel, so that the radial support of the portal steel ring is good, the self stiffness and anti-deformation ability of the portal steel ring are improved, and the true circularity of the portal steel ring is guaranteed. The formwork is installed and the concrete is poured in three layers from bottom to top, which can adapt to the concrete pouring requirements of different heights, effectively avoiding the process interruption problem caused by limited pouring height in traditional construction; the block steel ring is assembled and reinforced on the ground in advance, and then the complete portal steel ring is hoisted into the shield well, compared with the traditional block hoisting, the cumbersome process of underground block butt joint and secondary calibration is saved, the operation time is reduced, the construction efficiency is improved, and the true circularity of the portal steel ring is guaranteed.

[0056] For the skilled in the art to understand conveniently, further, the working flow of the construction method of the shield well integral type hole door steel ring provided by the application is as follows: After the segmented steel ring 1 is transported to the construction site, it is assembled according to the true circle parameters of the portal steel ring, the center and size are detected until the true circle parameters are qualified, and H-shaped support steel 5 is used to uniformly reinforce the portal steel ring in the radial direction (one end is collected at the center of the portal steel ring and connected, the other end is fixed with the inner wall of the portal steel ring); a plurality of first ring frame beams 6 corresponding to the portal steel ring installation area of the underground continuous wall of the shield well are cut off, the installation center point and the up, down, left and right positions of the portal steel ring are marked on the underground continuous wall, and the waterproof board is laid on the outside of the underground continuous wall of the portal steel ring, and the slide rail 9 is installed at the bottom of the shield well below the positioning point (the top surface elevation of the slide rail 9 is adjusted to adapt to the design elevation of the bottom of the portal steel ring, and the length covers the translation path of the portal steel ring hoisted to the installation position); the anchor steel bars 2 corresponding to the position of the slide rail 9 outside the portal steel ring are cut off, and then the main crane and the auxiliary crane are connected with the portal steel ring lifting point through the lifting tool, and after synchronous lifting, the portal steel ring is made vertical and separated from the auxiliary crane, and then the portal steel ring is hoisted to the slide rail 9 according to the positioning point; the portal steel ring is hoisted to the slide rail 9 according to the positioning point; the hand-operated hoist is installed on the portal steel ring and connected with the pre-buried lifting ring of the underground continuous wall, the connection between the lifting tool near the wall body and the main crane is disconnected and switched to the hand-operated hoist on the second ring frame beam 8 at the top of the portal steel ring, the portal steel ring is translated to the installation position through the hand-operated hoist installed on the portal steel ring and the hand-operated hoist on the second ring frame beam 8 at the top of the portal steel ring, and then the connection between the lifting tool away from the wall body and the main crane is disconnected and switched to the corresponding hand-operated hoist; the pre-embedded hole is preset above the portal steel ring, and the anchor steel bar is embedded in the underground continuous wall to fix the portal steel ring in the direction perpendicular to the underground continuous wall, the H-shaped counter-steel 10 is installed between the top of the portal steel ring and the top ring frame beam to fix the portal steel ring in the direction parallel to the underground continuous wall, and the gap between the portal steel ring and the underground continuous wall is sealed with a sealing element; on the portal side wall outside the upper and lower semicircles of the portal steel ring, the inner row of steel bars is tied near the underground continuous wall and welded with the portal steel ring and the anchor steel bars 2 of the portal steel ring, the outer row of steel bars is tied away from the underground continuous wall and welded with the portal steel ring and the anchor steel bars 2 of the portal steel ring, and then the inner and outer rows of steel bars are fixed with the tie bars; before the formwork is installed and the concrete is poured, steel pipes 7 are inserted into the pre-set positions between the steel bars tied on the portal side wall, water stop rings are welded outside the steel pipes 7 and grease is filled in the pipes; the slide rail 9 is removed, the first layer of formwork, secondary struts, main struts and throwing supports are installed outside the portal side wall at the first layer pouring height, the main struts are pulled against the anchor steel bars of the underground continuous wall with water stop pull rods, the vibration holes are opened on the first layer of formwork, the concrete is poured and vibrated from the gap at the top of the first layer of formwork, and the vibration holes are closed when the pouring reaches the vibration hole position; the hand-operated hoist is removed, the second layer of formwork, secondary struts and main struts are installed outside the portal side wall at the second layer pouring height, and then the concrete is poured from the gap at the top of the second layer of formwork after being pulled against the anchor steel bars of the underground continuous wall with water stop pull rods; the third layer of formwork, secondary struts and main struts are installed outside the portal side wall at the third layer pouring height, and then the concrete is poured through the pre-embedded hole on the second ring frame beam 8 at the top of the portal steel ring after being pulled against the anchor steel bars of the underground continuous wall with water stop pull rods, and the pre-embedded hole is closed after the third layer of concrete is vibrated through the pre-embedded hole.

[0057] The principles and implementation manners of the present application are described herein by using specific examples, and the above examples are only used to help understand the method of the present application and its core idea. The above description is only the preferred implementation manner of the present application. It should be noted that, due to the limited expression of the text, there are objectively infinite specific structures, and for ordinary skilled persons in the technical field, some improvements, refinements or changes can be made without departing from the principles of the present application, or the above technical features can be combined in an appropriate manner; the improvements, refinements, changes or combinations, or the direct application of the inventive concept and technical solution to other occasions without improvement, shall be regarded as the protection scope of the present application.

Claims

1. A construction method for an integral portal steel ring in a shield tunnel shaft, characterized in that, include: Step 1, Assembly and reinforcement of the portal steel ring: The segmented steel rings (1) are assembled according to the true circle parameters of the portal steel ring to form the portal steel ring, and the interior of the portal steel ring is reinforced radially using supporting steel (5); Step 2, Pre-treatment of the portal installation location and installation of the sliding rail: The first ring frame beam (6) of the portal side wall of the shield shaft corresponding to the portal steel ring installation area is cut off, the positioning point of the portal steel ring installation location is marked on the underground continuous wall, the waterproof membrane is laid, and the sliding rail (9) for the portal steel ring to be moved into place is installed at the bottom of the shield shaft. Step 3, Pre-treatment of anchoring steel bars for portal steel ring and hoisting of steel ring: Cut off the anchoring steel bars (2) on the outer side of the portal steel ring corresponding to the slide rail (9), and hoist the portal steel ring onto the slide rail (9) using hoisting equipment according to the positioning point, and move it to the installation position of the portal steel ring along the slide rail (9) by hand-operated hoist. Step 4, Anti-buoyancy fixing and gap sealing of the portal steel ring: Fix the portal steel ring to the underground continuous wall and the second ring frame beam (8) respectively by fixing components, and seal the gap between the portal steel ring and the underground continuous wall with sealing components; Step 5, binding and welding of steel ring reinforcement in the tunnel portal: binding the steel reinforcement of the side wall of the tunnel portal and welding the steel reinforcement to the corresponding semi-circular steel ring; Step 6, formwork installation and concrete pouring: Within the area of ​​the side wall of the opening, formwork installation and concrete pouring are carried out in three layers from bottom to top.

2. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, The process of assembling the segmented steel ring (1) according to the true circle parameters of the portal steel ring to form the portal steel ring includes: transporting the segmented steel ring (1) to the construction site and assembling it, and then checking that the center and size of the portal steel ring meet the true circle parameters to obtain the portal steel ring.

3. The construction method of the integral portal steel ring for shield tunneling shaft according to claim 1, characterized in that, The method of using supporting steel (5) to reinforce the interior of the tunnel portal steel ring in the radial direction includes: using H-shaped supporting steel (5) to reinforce the interior of the tunnel portal steel ring. The H-shaped supporting steel (5) is evenly distributed radially inside the tunnel portal steel ring, with one end converging at the center of the tunnel portal steel ring and connecting with each other, and the other end being fixedly connected to the inner wall of the tunnel portal steel ring.

4. The construction method of the integral portal steel ring for shield tunneling shaft according to claim 1, characterized in that, The process of cutting off the first ring frame beam (6) of the tunnel portal sidewall corresponding to the installation area of ​​the portal steel ring, marking the positioning point of the portal steel ring installation on the underground continuous wall, laying the waterproof membrane, and installing the slide rail (9) at the bottom of the tunnel for the translation and positioning of the portal steel ring includes: Step 2.1: Cut off multiple first ring frame beams (6) at the installation position of the steel ring of the tunnel portal within the side wall of the tunnel portal in the shield tunnel shaft; Step 2.2: Mark the center point of the portal steel ring installation position on the diaphragm wall, calculate the up, down, left, and right positions of the portal steel ring based on the center point, and mark them on the diaphragm wall; Step 2.3: Lay a waterproof membrane on the underground continuous wall outside the portal steel ring; Step 2.4: Install a slide rail (9) at the bottom of the shield shaft below the installation position of the portal steel ring, and adjust the top elevation of the slide rail (9) to match the design elevation of the bottom of the portal steel ring, and the length of the slide rail (9) covers the translation path of the portal steel ring from the hoisting position to the installation position.

5. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, According to the positioning point, the steel ring of the tunnel portal is hoisted and lowered onto the slide rail (9) using hoisting equipment, including: The main crane and the auxiliary crane are connected to the lifting points of the portal steel ring through lifting tools. The portal steel ring is first lifted synchronously to the designated height. While keeping their respective lifting radii unchanged, the main crane and the auxiliary crane cooperate to move and lift until the portal steel ring is upright. Then, the auxiliary crane is separated from the lifting point of the portal steel ring. According to the positioning point, the main crane is used to lift the portal steel ring onto the slide rail (9) at the bottom of the shield shaft.

6. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, Moving the device to the installation position along the slide rail (9) using a hand-operated hoist includes: Install a hand chain hoist on the portal steel ring and connect it to the pre-embedded lifting ring on the underground continuous wall. Disconnect the lifting device on the side of the portal steel ring near the underground continuous wall from the main crane and switch it to the hand chain hoist on the second ring frame beam (8) at the top of the portal steel ring. The portal steel ring is moved along the slide rail (9) to the side closer to the underground continuous wall by the hand-operated hoist installed on the portal steel ring, the main crane, and the hand-operated hoist on the second ring frame beam (8) at the top of the portal steel ring, and then moved to the installation position. After the steel ring is in place, disconnect the lifting device on the side of the portal steel ring away from the underground continuous wall from the main crane and switch it to the hand-operated hoist on the second ring frame beam (8) at the top of the portal steel ring.

7. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, Fixing the portal steel ring to the underground continuous wall and the second ring frame beam (8) using fasteners includes: After the steel ring is positioned, the portal steel ring is fixed in a direction perpendicular to the diaphragm wall by inserting steel bars into the diaphragm wall. H-shaped top steel (10) is installed between the top of the portal steel ring and the second ring frame beam (8) at the top of the portal steel ring, and the portal steel ring is fixed in a direction parallel to the underground continuous wall.

8. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, The process of binding the reinforcing bars of the portal sidewall and welding the reinforcing bars to the corresponding semi-circular steel rings includes: Tie the inner row of steel bars on the side wall of the tunnel entrance close to the underground continuous wall, and weld the inner row of steel bars to the tunnel entrance steel ring and the anchoring steel bars on the tunnel entrance steel ring (2); Tie the outer row of reinforcing bars on the side of the portal wall away from the underground continuous wall, and weld the outer row of reinforcing bars to the portal steel ring and the anchoring reinforcing bars on the portal steel ring (2); The inner and outer rows of reinforcing bars are fixed by tie rods.

9. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, Before step 6, the method further includes: inserting a steel pipe (7) at a predetermined position between the reinforcing bars of the side wall of the opening, welding water-stop rings on the upper and lower sides of the outside of the steel pipe (7), and filling the inside of the steel pipe (7) with grease.

10. The construction method of the integral portal steel ring for a shield tunnel shaft according to claim 1, characterized in that, The process of installing formwork and pouring concrete in three layers from bottom to top within the side wall area of ​​the tunnel entrance includes: Step 6.1: Remove the slide rail (9), install the first layer template, secondary rib, main rib and outrigger in sequence on the outside of the portal side wall within the first layer concrete pouring height range, and use water-stop tie rods to tie the main rib to the underground continuous wall reinforcement; open vibration holes on the first layer template; pour concrete and vibrate it between the underground continuous wall outside the portal steel ring and the first layer template through the gap at the top of the first layer template, and seal the vibration hole when pouring to the position of the vibration hole; Step 6.2: Remove the hand chain hoist, install the second layer template, secondary rib and main rib in sequence on the outside of the portal side wall within the second layer concrete pouring height range, and use water-stop tie rods to pull the main rib and the underground continuous wall reinforcement together. Pour concrete between the underground continuous wall outside the portal steel ring and the second layer template from the gap at the top of the second layer template. Step 6.3: Install the third-layer template, secondary rib and main rib in sequence on the outside of the portal sidewall within the height range of the third-layer concrete pouring. Use water-stop tie rods to pull the main rib and the underground continuous wall reinforcement together. Pour concrete between the underground continuous wall and the third-layer template outside the portal steel ring through the reserved hole on the second ring frame beam (8) at the top of the portal steel ring. Vibrate the concrete through the reserved hole and seal the reserved hole after vibration.

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