76 results about "Underpinning" patented technology

The invention discloses a storey-adding construction method for a basement with an existing box type foundation and a multi-layer frame structure, and belongs to the technical field of constructional engineering and city renewing.The storey-adding construction method comprises the following steps that S1, storey-adding buildings of the existing basement are evaluated; s2, underground diaphragm wall construction; s3, reinforcing the existing basement storey-adding building foundation; s4, the overground structure of the existing basement storey-adding building is reinforced; s5, foundation underpinning construction is conducted; s6, earth excavation is conducted at the storey-adding position of the existing basement; s7, construction of a storey-adding foundation bottom plate; and S8, layer-adding underpinning column and top plate construction. According to the storey-adding construction method for the basement with the box type foundation and the multi-layer frame structure, storey-adding transformation is conducted on the basement of an existing building, the usable area of the building is effectively increased, the construction efficiency is improved, the influence on the surrounding environment is reduced, and the urban development and the ever-increasing space requirements of people are met.

The invention discloses a temporary structure suitable for an assembly type station ending end, which comprises a temporary support structure arranged in a shape like a Chinese character'tian ', the temporary support structure is divided into a foundation support frame provided with an outer ring and a cross-shaped inner support frame body arranged between the foundation support frames, and the temporary structure further comprises an underpinning system arranged in the temporary support structure; through the construction method and structure of firstly building temporary steel beam columns and firstly supporting and then underpinning, the assembly starting point and end point positions of the full-prefabricated rectangular flat-top assembly type station are suitable for the working condition, the method can solve the problem of space and time conflict between the assembly trolley and the temporary steel stand columns, it is ensured that the assembly trolley is normally put into use, and the construction efficiency is improved. Meanwhile, the mounting and dismounting workload of the temporary section steel beam column is reduced, the construction efficiency is improved on the premise of ensuring the splicing quality, the high-place operation risk is reduced, meanwhile, normal construction of a post-pouring beam column system can be ensured, and the mounting and dismounting amount of large section steel components is reduced.

The invention belongs to the field of urban renewal construction, and relates to a method for adjusting elevation and landing in place in building translation construction. In the process that a building returns and resets to a newly-built basement top plate, firstly, a temporary platform composed of a heightening steel beam and a heightening steel cushion block is laid on the newly-built basement top plate in advance so as to solve the height difference problem existing between the newly-built basement top plate and a translation rail. Secondly, triangular haunching plates are additionally arranged at the corners of the wall clamping beams for supporting the building; and a landing jack is directly arranged below the haunching plate. By means of the arrangement mode, the eccentric bending moment borne by the underpinning structure is greatly reduced, and absolute safety in the landing process is ensured. And finally, a set of repeatable standardized circulating steps is designed, and the effect that the existing building is always reliably supported in the landing process is achieved. The invention aims to overcome the defects in the prior art, and provides the building translation landing method which is safe to operate, accurate to control and capable of effectively coordinating the foundation height difference and optimizing the landing stress path.

The present application relates to the technical field of tunnel excavation, in particular to a multifunctional underground excavation trolley, comprising: a trolley frame, a rotary excavating arm arranged on the trolley frame, the rotary excavating arm comprising a deflection assembly, a first movable assembly, a second movable assembly, a rotary driving member and an excavating assembly; a bucket detachably mounted on the rotary excavating arm; a mechanical arm detachably mounted on the rotary excavating arm, the mechanical arm detachably mounting a drilling mechanism and a nozzle clamping mechanism; a grouting system connected to the drilling mechanism or the nozzle clamping mechanism; and a scraper conveyor fixed on the trolley frame. The present application can satisfy the operation of tunnel excavation, slagging, drilling, arching and auxiliary spraying, cover all processes in the process of shallow underground excavation of power tunnel and primary support, and solve the problems of frequent site conversion of multiple equipment, inability to change lanes due to small tunnel, long equipment conversion time, low construction efficiency, high construction cost and the like.

The application discloses an isolation structure and method for reducing displacement of a railway pile foundation caused by shield construction, and the isolation structure comprises underpinning beams and 2N columns of inclined piles, and N is greater than or equal to 2; the underpinning beams are located below an existing railway subgrade; each column of inclined piles comprises a plurality of inclined piles with the same inclination direction and inclination angle; the 2N columns of inclined piles are divided into two groups; the pile bottoms of one group of the inclined piles are located on one side of a to-be-constructed shield tunnel, and the pile bottoms of the other group of the inclined piles are located on the other side of the to-be-constructed shield tunnel; two adjacent columns of inclined piles in the same group are arranged in an X-shaped cross mode; the pile tops of the two groups of the inclined piles are connected with the underpinning beams and form a portal type support structure; the to-be-constructed shield tunnel passes through the portal frame surrounded by the inclined piles and the underpinning beams; and the two groups of the inclined piles are located between original railway pile foundations and the to-be-constructed shield tunnel. The application can resist the horizontal deformation of the original railway pile foundations caused by the shield tunnel construction, reduce the settlement of the railway subgrade, and effectively protect the normal operation of the railway.

The application discloses a tunnel pile foundation underpinning construction method, and the construction method comprises the following steps: S100, construction preparation; S200, tunnel bench method construction to underpinning pile; S300, construction of advanced support; S400, pile body concrete removal, construction of initial support; S500, excavation of soil bodies on both sides of the lower part of the underpinning pile, and timely initial support closure; S600, pouring of side wall and arch part secondary lining; S700, removal of temporary cross brace after the secondary lining concrete reaches the design strength; S800, bottom plate construction; S900, repeating S200-S800 until all pile foundation underpinning is completed. The tunnel pile foundation underpinning construction method effectively utilizes the transformation of the initial support and the secondary lining of the tunnel to the load of the fire pool, guarantees the safety and normal use of the fire pool structure, and has small engineering quantity, and can save investment. By utilizing the mechanism of passive underpinning, the pile foundation bears the force by itself, the pile foundation intruding into the tunnel is removed and cut step by step and root by root, and the safety and normal use of the fire pool structure are guaranteed.

This invention relates to a bridge underpinning support device and construction method under low clearance conditions. φ900 steel pipe columns support crossbeams, longitudinal beams, and connecting beams on both sides of the piers of the bridge section to be underpinned. The longitudinal and crossbeams are fixed using limiting devices. Distribution beams and stiffening plates are symmetrically installed below the crossbeams. Jacks and φ609 steel pipe columns are symmetrically installed between the distribution beams and stiffening plates and the bridge, with the jacks installed upside down. A conversion cap is installed between the jacks and the φ609 steel pipe columns. This invention solves the problem of limited clearance under existing bridges, making traditional component hoisting methods unusable. By breaking down the bridge support into smaller parts, the original elevation is lowered by 2-3 meters. Multiple replacements of jacks, conversion sections, and standard sections are used to raise the support to the original elevation, meeting the requirements for bridge underpinning construction. Through modular adaptive adjustment, the installation difficulties of underpinning supports under existing operating bridges are successfully solved.

This invention discloses a method for underpinning culvert foundations in roadbeds, relating to the field of civil engineering technology. The method includes the following steps: cleaning the culvert to expose the culvert foundation; installing support components on both sides of the culvert foundation to support the cover plate; breaking the bottom slab in the middle of the culvert and re-pouring reinforced concrete at the bottom slab location; installing support components on the re-pouring reinforced concrete to support the cover plate; breaking the bottom slabs on both sides of the culvert and under the support walls, and then re-pouring reinforced concrete to replace the original bottom slabs; after the re-pouring reinforced concrete reaches its design strength, removing the support components inside the culvert to restore its drainage function. The aforementioned method for underpinning culvert foundations is applicable to natural foundation underpinning of frame structures. During the underpinning process, the building can be used normally without speed restrictions, which helps reduce the impact of the underpinning on the surrounding area.

The invention provides an air curtain anti-drag underpinning method and an underpinning structure, and relates to the technical field of ruin protection engineering, a stable air curtain can be formed between the underpinning structure and a soil body through the designed air curtain, friction force is remarkably reduced, disturbance to a ruin is reduced, and integrity and stability of the ruin are protected to the maximum extent; gradual air curtain starting, accurate jacking and micro-disturbance control measures in the construction process ensure that the underpinning process is accurate and controllable, and the influence on the ruins is further reduced; in the construction process, according to the counter-force requirement of vertical underpinning, dynamic balance control over vertical deformation of the site building is achieved through gas pressure control of the gas curtain system.

The invention discloses a stand column repairing method which comprises the steps that S1, a defective stand column is detected, and a defective section of the defective stand column is found out; s2, temporary supporting pieces are arranged on earthworks on the two sides, in the length direction of the supporting beam, of the faulty stand column correspondingly, each temporary supporting piece is provided with a supporting end capable of moving in the vertical direction, the supporting ends are connected to the supporting beam, and the temporary supporting pieces are started to lift the supporting beam; s3, earthwork between the faulty stand column and the temporary supporting piece is excavated till the faulty section of the faulty stand column is completely exposed; s4, the problem segments are cleaned; s5, concrete is poured on the outer side of the problem segment to form a repaired concrete segment; and S6, the supporting beams are reinforced. Compared with the prior art, the problem stand column can be repaired in situ, two stand column piles and cross beams do not need to be newly constructed for underpinning according to a conventional scheme, and the construction period and the manufacturing cost can be better saved.

The invention discloses a self-adaptive heavy-load wheeled vehicle for building moving, and mainly relates to the field of building moving. Comprising a vehicle body arranged below a building underpinning beam, the vehicle body comprises a multi-cylinder jack and a lifting barrel base, a plurality of cylinder bodies are arranged in the multi-cylinder jack, piston rods are slidably connected into the cylinder bodies in the vertical direction, an oil inlet nozzle and an oil return nozzle are arranged on the multi-cylinder jack, and a plurality of lifting holes are formed in the positions, corresponding to the piston rods, of the lifting barrel base. Lifting columns are slidably connected into the lifting holes, wheel set supports are arranged at the bottoms of the lifting columns, and rolling wheels are rotatably connected to the wheel set supports. The device has the beneficial effects that the technical problem that a building is easily damaged due to uneven stress of a walking mechanism when the building encounters an uneven or settlement condition in the moving process can be solved, and the downward extending distance of the wheel set bracket and the rollers can be automatically adjusted according to the condition of a walking surface; the stability of vertical supporting force of all positions of the bottom of the building is guaranteed, the building is prevented from being damaged, and the integrity of the building after movement is guaranteed.

The utility model discloses a kind of for joist pulls out column's underpinning jacking platform, including frame body underpinning platform and jacking platform;Frame body underpinning platform is set to the lower outer periphery of column to be constructed, and by four steel columns fixedly supported on foundation respectively arranged at its corner position;Jacking platform is set to the upper outer periphery of column to be constructed, jacking platform is connected by being anchored with the column to be constructed by multiple along its circumferential uniform setting of planting nail, and the gap between jacking platform and the column to be constructed is filled with grouting material;Four corner positions between the frame body underpinning platform and the jacking platform are respectively provided with underpinning support, and four edges of the frame body underpinning platform and the jacking platform are respectively provided with vertical jack.The utility model guarantees the effective connection of underpinning platform and the upper structure of column to be constructed, realizes the jacking unloading of upper structure of column to be constructed, and effectively reduces the operation risk in jacking unloading construction process.

The invention discloses a construction method for a shield to pass through an existing pile foundation, which belongs to the technical field of interval shield tunnel underpass, and comprises four parts of pile foundation underpinning design, pile foundation underpinning automatic monitoring and precision control, shield active direct grinding crossing and shield crossing automatic monitoring and cooperative control. According to the pile foundation underpinning design, the stratum disturbance influence of shield crossing is fully considered, and the strength, rigidity and node design of an underpinning structure are optimized; an automatic monitoring system is adopted for pile foundation underpinning and shield crossing, synchronous transmission and fusion analysis of monitoring data are achieved, high-precision control measures are combined, the construction state is fed back in real time, and automatic deviation correction is achieved. The method has the advantages that the problems that in the prior art, shield crossing influences are not considered in pile foundation underpinning design, the passive cutting risk of shield crossing is high, and cooperative control over the two is insufficient are solved, the construction safety, reliability and efficiency are improved, and the method is suitable for shield crossing pile foundation engineering in urban dense building areas.

The application relates to the technical field of building municipal foundation pit support and foundation piles, in particular to a construction method of underpinning piles and anchor piles for detection. The construction method comprises the following steps: S1. early construction; S2. determining a pile position; S3. small geological drilling machine construction; S4. small rotary jet drilling machine construction; S5. small spiral anchor rod drilling machine construction; S6. underpinning pile construction; S7. anchor pile construction; S8. cyclic construction; S9. static load test; and S10. slope protection pile construction. In the construction method, four to five small-diameter steel pipes are used to replace a large-diameter steel pipe as the underpinning piles and the anchor piles, the problem of insufficient power of the remanufactured small long spiral drilling machine is solved, and the problem that the reaction force of the large-diameter steel pipe is difficult to provide after rotary jetting and static pressure implantation is solved, so that the application has the effect of adapting to the narrow construction site of old house reconstruction, and large-scale mechanical equipment cannot enter the site.

The invention discloses a construction method for micro pile group foundation reinforcement and foundation underpinning in a subsurface tunnel, which comprises the following steps of: 1) pre-burying steel sleeves: pre-burying the steel sleeves at the front end and the rear end of a primary support inverted arch grid and between two adjacent grid steel frames during construction of a primary support structure; 2) improving the down-the-hole drill; (3) drilling a micro pile hole in the pre-buried steel sleeve; (4) forming a micro pile; (5) carrying out bearing capacity acceptance inspection on the micro piles; (6) waterproof treatment is conducted, specifically, waterproof treatment is conducted on the pile head after the tunnel waterproof isolation layer is constructed; and (7) tunnel secondary lining construction is conducted, the pile heads of the micro piles are anchored into a secondary lining bottom plate, and the secondary lining bottom plate is supported by the micro pile groups. The tunnel primary lining can be effectively prevented from being damaged and disturbed; main body structure sinking and cracking caused by foundation problems in the later period can be avoided, and the durability and the service life of a building are improved; and flexible construction can be carried out in a limited space in the tunnel by adopting a standardized construction process.

The utility model discloses bridge underpinning and jacking equipment which comprises a device body, and the device body comprises an original bearing table, a group of first steel supports, a group of second steel supports, a group of supporting blocks, a supporting bridge and a section steel transverse connection reinforcing device. The first steel support, the second steel support and the supporting block are all installed on the top of an original bearing table, the supporting bridge is supported on the first steel support and the second steel support, and the multiple sets of profile steel transverse connection reinforcing devices are installed between the first steel support and the second steel support. The first steel support and the second steel support are each of a cylindrical structure, and conversion connectors are installed on the tops of the first steel support and the second steel support. The device is good in economical efficiency, the early-stage installation time of the steel support and the installation and replacement time of the steel support during jacking are greatly shortened, the work efficiency is improved, and the construction safety risk of workers is greatly reduced.

The application discloses a conversion method of a small-bay basement shear wall reverse construction system, which comprises the following steps: removing internal supporting pile columns of a basement structure to be constructed, retaining supporting pile columns of an outer contour and a central axis position of a shear wall wall limb to be constructed; erecting a main underpinning beam on the top of the retained supporting pile columns; adding supporting pile column one at a position where a vertical supporting structure is absent at the bottom of the main underpinning beam, and moving part of the supporting pile columns deviated from the position of the intersection of the main underpinning beam to the adjacent intersection as supporting pile column two; erecting a secondary underpinning beam under the shear wall wall limb to be constructed in the removed internal supporting pile columns, and prolonging both ends of the secondary underpinning beam to be connected with the main underpinning beam as a whole; pouring a structural plate between the main underpinning beam and the secondary underpinning beam to complete the construction of the basement B0 layer structure; excavating and constructing the basement B1-Bn layer main underpinning beam, the secondary underpinning beam and the structural plate by using a reverse construction method, and constructing an upper main body structure upwards; and backfilling the basement shear wall to complete the construction of the basement structure.

The invention discloses a construction method for bridge pier underpinning. The construction method comprises the steps that a gate-type pier lower structure is newly built; prefabricating a steel cover beam; the steel cover beam is horizontally moved to the side edge of an original pier stand column through a beam body moving and transporting device; a temporary supporting system is built on the side edge of an original pier stand column, and an existing bridge is supported; the original pier stand column structure is dismantled; and the prefabricated steel cover beam is assembled in place. By implementing the construction method for underpinning the bridge pier, the existing bridge pier for operating the rail transit can be integrally, quickly and accurately underpinned in a narrow space. The steel cover beam is prefabricated and then transferred to the construction site, the problems that the existing bridge supporting structure is built in a cast-in-place mode on site, traffic is affected for a long time, the nearby environment is polluted are solved, and the stability of the existing bridge structure is guaranteed by being matched with a temporary supporting system and dismantling and transporting away an original bridge pier.

The invention provides a foundation underpinning structure of an underground power pipe gallery and a construction method of the foundation underpinning structure. The foundation underpinning structure comprises fender posts, longitudinal beam components and an underpinning mechanism. The underpinning mechanism comprises a lower section steel beam component, a vertical force measuring point, an upper section steel beam component and a connecting assembly. The fender posts, the longitudinal beam components, the lower section steel beam components, the upper section steel beam components and the connecting assemblies are combined to form a pull-up and lift-down foundation underpinning structure for the underground electric power pipe gallery, the bearing capacity is high, the stress structure is clear in stress, and the self-weight requirement of the large underground electric power pipe gallery is met; according to monitoring data fed back by vertical force measuring points at different positions, the corresponding connecting assemblies can be adjusted in real time to stretch out and draw back so as to adjust stress of the lower section steel beam component and the upper section steel beam component, it is ensured that the underground power pipe gallery is evenly stressed, deformation control precision is high, deformation of the underground power pipe gallery is conveniently controlled within an allowable range, and the safety of the underground power pipe gallery is improved. And the operation safety of the pipe gallery during construction is ensured.

This invention discloses an installation structure and method for filling in gaps in stone slabs. The installation structure includes: a first L-shaped component, comprising a first vertical plate and a first horizontal plate rotatably connected to the back of the filling stone slab about a first rotation axis; a second L-shaped component, comprising a second vertical plate and a second horizontal plate rotatably connected to a keel frame about a second rotation axis; and a traction rope for pulling the second vertical plate to rotate toward the first vertical plate; wherein the first rotation axis is parallel to the second rotation axis and the first rotation axis is higher than the second rotation axis; a push plate is also fixed on the first vertical plate; an insertion hole is provided on the second horizontal plate, the diameter of the insertion hole being larger than the thickness of the first horizontal plate; and a traction point is provided on the second vertical plate. The installation structure improves construction safety.

The utility model provides a temporary underpinning structure of a latticed column, which belongs to the technical field of underground engineering construction of urban rail transit and comprises two first connecting steel plates, two second connecting steel plates, two third connecting steel plates, two fourth connecting steel plates, two support pressing rods and two support pull rods. The two supporting pressing rods and the two supporting pull rods are connected to form a triangle. The vertical load of dismantling the latticed columns is transmitted to the latticed columns on the left side and the right side adjacent to the latticed columns, it can be guaranteed that after the latticed columns are dismantled, structural stress is reasonable, and normal operation and safe passing of an existing road surface are guaranteed. The utility model has the advantages of simple integral structure, fewer parts for assembly and high integral structure rigidity, ensures the normal operation and safe passage of the existing road surface, and is fast in construction, low in cost and suitable for engineering application and popularization.

The application provides a spliced trailer displacement underpinning device and trailer displacement method, relates to the technical field of civil construction, and comprises an angle steel support, a clamping column channel steel, a bearing type steel, a locking piece and an angle steel diagonal brace. In view of the problem that the current concrete underpinning structure cannot be recycled and is wasted, the underpinning structure of the displaced building is established by using a steel structure, the whole is detachably connected, the connection strength and the bearing strength with the building are effectively ensured, the underpinning structure can be repeatedly assembled and recycled, the engineering cost is reduced, material waste is reduced, and the displacement requirement of the building is met.

This invention discloses a cut-and-cover beam and temporary pile structure and construction method for pile foundation replacement. It includes a horizontal support beam, a longitudinal support beam, temporary piles, and a retaining structure surrounding the existing pile foundation cap structure. The existing pile foundation cap structure is connected to the horizontal and longitudinal support beams. Both ends of the horizontal support beams are connected to the retaining structure, and both ends of the longitudinal support beams are connected to the horizontal support beams. The temporary piles are positioned between the existing pile foundation cap structure and the retaining structure. Furthermore, this invention proposes a construction method for this structure, employing the design concept of "cut-and-cover beam and temporary pile structure system to replace existing ground-level entrance pile foundations." This allows for rapid backfilling of the top slab, traffic restoration, and pipeline relocation. Simultaneously, after the newly constructed cut-and-cover underground structure system is closed, the temporary piles are removed, forming a large-span, column-free underground space. This allows the cut-and-cover underground structure system to bear the vertical load of the existing ground-level entrance during the operational phase, ensuring the safe operation of the existing subway during pile foundation replacement.

The application discloses a method for underpinning of existing buildings crossing underground traffic facilities, a structure and an internal structure reconstruction method. The method comprises the following steps: constructing a bearing platform on both sides of the existing building crossing the underground traffic facilities, and constructing a plurality of anchor rods and static pressure piles downwardly through the bearing platform to form a pile foundation structure; constructing a foundation beam in each original outer wall between the pile foundation structure, and constructing a plurality of interval distributed foundation beams between the foundation beams in the underground traffic facility area, so that the foundation beam and the foundation beam form a frame beam foundation structure; and constructing a raft foundation, so that the pile foundation structure, the frame beam foundation structure and the raft foundation form an existing building underpinning structure. The application can realize the underpinning construction of the existing building crossing the underground traffic facilities without affecting the existing underground traffic facilities or the construction of the newly added underground traffic facilities, and ensures the safety of the existing building before and after the reconstruction.

This invention relates to a method and structure for underground space expansion based on a pre-cut groove and load-bearing system. Underground expansion projects may cause ground displacement, posing safety hazards to the surrounding environment. This method involves opening holes in the sidewalls of existing underground structures, removing reinforcing steel from the sidewalls and retaining structures according to the outline of the pre-cut groove; drilling laterally at the opening location, then longitudinally extending and cutting to form the pre-cut groove, simultaneously injecting concrete into the pre-cut groove; excavating small pilot tunnels and shafts below the cover plate; constructing support piles within the shafts; fully excavating and constructing the bottom slab, sidewalls, and top slab; pouring a ring beam, and integrally superimposing the ring beam with the cover plate, top slab, sidewalls, and longitudinal beams. In this invention, the cover plate injection and pre-cut groove construction are synchronized, achieving the effect of cutting and constructing simultaneously. Furthermore, a high-rigidity pipe roof is installed within the cover plate thickness to achieve cover plate-type advanced support. The support piles and cover plate form a vertical plate-column type advanced support force transmission system, effectively avoiding ground displacement that may occur during underground project expansion.

The invention relates to the technical field of building engineering foundation underpinning and reverse construction, and discloses a foundation underpinning structure and method for a reverse basement below an existing protection building. The foundation underpinning structure comprises two prefabricated joists, and the sides, close to each other, of the two prefabricated joists make contact with each other; a horizontal stabilizing mechanism is arranged in the two prefabricated joists and outside the two prefabricated joists, a reinforcing supporting mechanism is arranged in the horizontal stabilizing mechanism, and the horizontal stabilizing mechanism comprises two sets of supporting legs. According to the foundation underpinning structure and method for the top-down basement below the existing protection building, the horizontal stabilizing mechanism is arranged, a high-bearing-capacity structure is formed by the prefabricated joists and the H-shaped steel framework, the disturbance and crack problems of cast-in-place are avoided, the hydraulic jacks at the corresponding positions are automatically started through the controller, the height of the joists is adjusted, and the foundation underpinning effect is achieved. And by means of the prefabricated joist and intelligent leveling design, the disturbance risk is reduced, and the effect of avoiding foundation cracking and structural damage is achieved.

The invention provides a construction method for multi-time conversion and underpinning of deep foundation pit engineering under an existing building. The construction method comprises the steps that a tray beam system is constructed; a jacking underpinning pile is constructed; the engineering piles are constructed; a lifting equipment system is arranged on the tray beam system; the lifting equipment system lifts the existing building by taking the jacking underpinning pile as a counter-force supporting point; earthwork at a basement top plate below the existing building is excavated, and the basement top plate is constructed; a vertical jacking and leveling device is arranged between the basement top plate and the tray beam system; after a balanced underpinning state is reached, an equipment system is lifted; the existing building is located on the vertical jacking and leveling device, earthwork below the existing building is excavated, and a basement structure is constructed; according to the basement structure, engineering piles serve as temporary basement vertical components or permanent basement vertical components. The invention relates to the technical field of constructional engineering, and can solve the problems that in the prior art, construction of a deep foundation pit below an existing building has large safety threat to an existing building structure, and load conversion is unstable.

The application discloses a kind of subway station reserved crown beam underpinning construction method, comprising the following steps: S1, the position of underpinning pile is determined between station main body and auxiliary pavilion structure at the enclosure pile or enclosure wall, by embedding lattice column in the enclosure pile or enclosure wall at the position, and pouring concrete, make enclosure pile or enclosure wall and lattice column jointly load bearing support crown beam, track beam and gantry crane;S2, when auxiliary pavilion structure construction, break part of enclosure pile or enclosure wall and lattice column outer concrete, so that the lattice column with lattice column top and bottom enclosure pile or enclosure wall of internal concrete forming power support is formed simultaneously, while the roof, floor construction between station main body and auxiliary pavilion structure;S3, after shield construction, cut the lattice column between roof and floor, complete the connection of roof and floor.The construction method of the application can reduce construction joint, reduce the risk of water leakage, while auxiliary pavilion and station main body shield construction is synchronized, improve the construction efficiency.

The invention discloses a bridge pier underpinning method for a steel box girder, and relates to the technical field of bridge engineering. Aiming at the problems that the road clearance height is insufficient, the construction period is long and the structural stability is difficult to guarantee due to the existing bridge pier underpinning method, the bridge pier underpinning method of the steel box girder comprises the following steps of: respectively connecting cross beams on two sides of the cross beams of the existing steel box girder to extend and lengthen, supporting the other end of the extension section of the cross beam on a newly-arranged bridge pier upright post, and then, connecting the cross beams with the bridge pier upright post; a jack set is arranged between a new bridge pier stand column and a cross beam extending section, the jack set is synchronously pressurized to the value the same as the actual dead load vertical force in a grading mode through a hydraulic synchronous jacking system, it is ensured that the vertical force borne by an original bridge pier stand column top face support is transferred to the jack set, and finally a permanent support is installed on the top face of the new bridge pier stand column. And the jack set is synchronously unloaded, so that the existing bridge pier is supported on the newly-built bridge pier through the cross beam extension section.