CN112177374A

CN112177374A - Corridor reconstruction method for realizing flat-floor entrance of existing building by additionally arranging elevator

Info

Publication number: CN112177374A
Application number: CN202011107805.8A
Authority: CN
Inventors: 夏正军
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-10-16
Filing date: 2020-10-16
Publication date: 2021-01-05

Abstract

The invention provides a corridor reforming method for realizing flat-floor entrance by adding an elevator in an existing building, which comprises the steps of adding a temporary support to an intermediate platform, dismantling the outer wall of the corridor of the existing building, utilizing an existing beam or a ring beam or adding a beam, selecting a corridor structure, dismantling half of a stair section, the intermediate platform and installing a horizontal corridor in sequence, wherein one end of the horizontal corridor is connected with an entrance platform, the other end of the horizontal corridor is connected with the beam and is sequentially connected with an elevator platform, the same elevator is combined to realize flat-floor passage, the other half of the stair section, the intermediate platform, the temporary support and the installation stair section are sequentially dismantled, one end of the stair section is connected with the entrance platform, the other end of the stair section is connected with an adjacent layer beam and is sequentially connected with the elevator platform to realize upper and lower floor stair passage, and railings are installed after all components are firmly fixed, the method fully considers the conditions of different corridors, achieves the purpose of adding the elevator to, the assembly type construction method is high in construction efficiency, low in manufacturing cost, small in influence on residents and safe in construction process.

Description

Corridor reconstruction method for realizing flat-floor entrance of existing building by additionally arranging elevator

Technical Field

The invention belongs to the field of buildings, and particularly relates to a corridor reconstruction method for realizing flat-floor entrance of an existing building by additionally arranging an elevator.

Background

In recent years, the nation changes and positions old urban districts into important civil engineering and development engineering, and has very important significance for meeting the good living needs of people, promoting the internal expanding needs of people, promoting the urban updating and development construction mode transformation and promoting the economic high-quality development.

The embodiment of the additional elevator has three modes of half-floor entrance, sub-level entrance and level entrance. The half-floor entrance means that the person who takes the elevator arrives at the floor and then walks to the home by half floor, as shown in fig. 1. The problem of height is solved by a ramp when a sub-flat layer enters a house as shown in figure 2, so that the original stair does not need to be dismantled, and construction can be completed only by additionally building. The elevator parking platform and the entrance door platform are located at the same elevation, the target function of the elevator is really realized through corridor connection, and the old people go out without obstacles to carrying articles.

Half-floor area of registering one's residence is little, simple structure, need not reform transform old building, and the cost is low, can satisfy and install elevator policy additional, and the acceptance is easily passed through. But the intention of adding an elevator without climbing stairs is not completely realized, and the old with inconvenient movement and the heavy objects carrying are still inconvenient.

The shortcoming of half-floor entering can be locally improved by subflat entering, a local ladder section is changed into a ramp, the old people can conveniently go out and carry heavy objects, the structure is basically not involved in the transformation of an old building, and the construction cost is low. But the existing building structure is limited, the height of the channel is low, and the standard requirement of a fire-fighting evacuation channel can not be met generally; difficult to pass fire-fighting acceptance.

Currently, most existing ways are half-floor-to-home or sub-floor-to-home. Under the condition that some existing buildings meet the conditions, flat floor entry is realized by means of adding galleries and the like. Such as:

1. and the flat-layer house entry is realized by utilizing the existing balcony or by adding a corridor. The existing balconies are relatively good choices, but the balconies of the existing buildings are often arranged in the south direction, so that the ventilation and lighting of the buildings are affected, and meanwhile, due to the limitation of the space between the buildings, the balcony is often unable to be implemented for ensuring the fire fighting channel of the residential area. The corridor is added, namely, the corridor enters the position of a toilet or a kitchen or a restaurant of an existing building through the north corridor, the original position of entering the house is changed, the use function of the existing building is influenced, the corridor is additionally arranged, a foundation and a stand column need to be arranged, the load of the corridor is borne, and the cost of additionally occupying the green space area is high. The flat floor entrance is the initial desire of residents to install elevators and is a real demand, but in view of the reasons that the existing building structure is limited, the normal life of the residents is influenced by the structure construction, the manufacturing cost is high and the like, finally, most of the residents still select a half-floor entrance mode.

2. When the building originally faces the public channel of the outer wall, only the wall opening at the outer side of the public channel needs to be butted with the platform of the elevator lobby, and flat floor entrance can be well realized. The house type is rare and can not be obtained when meeting.

3. A method for realizing flat-floor entrance by modifying a corridor has also been proposed, as shown in fig. 3, but the following problems exist:

1) demolish the corridor step, reform transform original two-run stair into the combination of single-run stair + horizontal vestibule, the work progress with the completion back, all change the structure atress distribution of existing building, whether have the influence to existing building, need carry out computational analysis.

2) The corridor structure generally cannot meet the requirements of building and fire-fighting regulations, and if the width of the stairs is less than 0.26m, the height is more than 0.175m, and the width of the platform is less than 1.2 m.

3) If the concrete cast-in-place mode is adopted for transformation, the construction difficulty in a narrow space is very high. A support scaffold is erected in cast-in-place construction, resident passage is seriously influenced, and great potential safety hazards exist.

4) Due to the limitation of the concrete construction process, the construction time is long, residents cannot enter and exit for a long time, and the influence on the normal life of the residents is serious.

For another example, patent application 2019219229487 discloses an old building modified elevator flat floor entrance structure, which has the following defects:

1) the ladder sections are supported by adopting upright posts and supporting pieces; the step load is conducted to the ground through the stand column, and generally, the original terrace can not meet the bearing capacity requirement, and pile foundations need to be additionally arranged or foundations need to be enlarged. Because the corridor is narrow, large-scale mechanical construction cannot be adopted, the manual operation efficiency is extremely low, and the disturbance is generated on the original building foundation to influence the safety of the original building structure.

2) The additionally-installed platform and the upright post are both of reinforced concrete structures, and the time for influencing the entrance and exit of residents and the normal life is too long due to the construction process limitation of reinforced concrete (generally, a 28-day strength detection qualified report of concrete is required to be checked and accepted).

3) The patent does not analyze the stress change of the structure related to the connection of the new and old structures of the added elevator, does not analyze the construction safety of the construction process and the influence on the entrance and exit of residents and normal life, and both the safety and the feasibility are difficult to determine.

The method has great significance on achieving the purpose of achieving flat-floor entrance by additionally arranging the elevator on the existing building in the shortest time and under the condition of ensuring safety by a simple, quick and convenient method.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to realize the flat floor entry by adding the elevator in the existing building, fully considers the conditions of different corridors, can achieve the purpose of realizing the flat floor entry by adding the elevator, does not occupy additional land, has high assembly construction efficiency, saves the manufacturing cost, has small influence on residents, is safe in the construction process, can meet the standard requirements, and has good economic and social benefits.

The technical scheme of the invention is as follows:

a corridor reconstruction method for realizing flat-floor entrance by adding an elevator in an existing building comprises the following steps:

the method comprises the following steps: a corridor reconstruction scheme is compiled, the safety of the reconstruction construction process is ensured, and the reconstructed corridor and the reconstructed stair meet the relevant standard requirements of buildings and fire fighting;

step two: a temporary support is additionally arranged on the middle platform;

step three: demolishing the outer wall of the existing building corridor, and then selecting one of the following three corridor structures according to the situation:

a) the existing building corridor space is enough, the stair reconstruction carried out in the space can meet the requirements of building and fire-fighting specifications, the floor layer is provided with a reserved beam or ring beam of a beam or ring beam, the beam or ring beam is detected, if the bearing capacity is insufficient, the beam or ring beam is reinforced to meet the requirements, and the building corridor space is suitable for an A-type structure;

b) the space of the existing building corridor is enough, the stair reconstruction carried out in the space can meet the requirements of building and fire-fighting standards, and the cross beam meeting the bearing capacity requirement is additionally arranged without the cross beam or the ring beam, so that the building corridor is suitable for a B-type structure;

c) the corridor space of the existing building corridor is insufficient, the stair reconstruction carried out in the space cannot meet the building and fire-fighting standard requirements, the existing beam or ring beam is cut off as required by the beam or ring beam, the beam is newly added according to the design requirement, and at the moment, the horizontal corridor and the stair section extend out of the corridor space and are suitable for a C-shaped structure;

the corridor structure comprises an elevator platform and a service platform, and the corridor structure comprises N layers, wherein N is more than or equal to 2; the corridor structure of the (N-1) th floor further comprises a cross beam and a horizontal corridor; the horizontal corridor is horizontally arranged, one end of the horizontal corridor is connected with the cross beam and is connected with the elevator platform in the same direction, and the other end of the horizontal corridor is connected with the entrance platform; one end of the ladder section is connected with the cross beam and is in direct connection with the elevator platform and the horizontal corridor, and the other end of the ladder section is connected with the entrance platform of the adjacent floor;

the crossbeam is arranged at the connecting end of the horizontal corridor and the ladder section, which is far away from the service platform, and is connected with the horizontal corridor in a flush manner;

the crossbeam is arranged at the connecting end of the horizontal corridor and the bench section, which is far away from the service platform, is positioned below the horizontal corridor and is connected with the horizontal corridor and the bench section;

the cross beam is arranged below the middle ends of the horizontal corridor and the bench section, is directly connected with the lower part of the bench section, and is connected with the lower part of the horizontal corridor through a supporting piece;

after the outer wall of the existing building corridor is dismantled, the two ends of the beam are horizontally and firmly connected with the reinforced concrete structures of the wall bodies on the two sides, and the joint is not made of reinforced concrete and needs to be reinforced, so that the structural bearing capacity of the newly-added beam meets the requirement.

Step four: according to the corridor structure selected in the step three, the A-shaped structure reserves a cross beam or a reinforced ring beam; the B-type structure is additionally provided with a cross beam according to the design requirement; the C-shaped structure is used for dismantling the cross beam or the ring beam and newly adding the cross beam according to the design requirement;

step five: sequentially dismantling the half-width bench and the middle platform, and sequentially installing the horizontal vestibule; the horizontal corridor is horizontally arranged, one end of the horizontal corridor is connected with the entrance platform, and the other end of the horizontal corridor is connected with the cross beam and is connected with the elevator platform; the elevator, the elevator platform, the horizontal corridor and the entrance platform form an entrance and exit channel to realize flat-layer entrance;

step six, dismantling the other half of the bench, the middle platform and the temporary supports in sequence, and installing the bench in sequence; one end of the ladder section is connected with the landing, and the other end of the ladder section is connected with the adjacent floor beam and is in direct connection with the elevator platform, so that the stair traffic of upper and lower floors is realized;

step seven: the elevator platform, the corridor and the service platform are adjusted to be parallel and level and are firmly fixed, the bench is adjusted and is firmly fixed, and the handrail is installed.

And (4) allowing the resident to pass under normal conditions, allowing the resident to take the elevator to reach the elevator platform on the floor, and reaching the platform for the resident through the corridor, so that the level floor entrance is realized. When the elevator is stopped, the personnel go up to the elevator platform of the upper floor or go down to the elevator platform of the lower floor through the stairs and reach the platform of registering one's residence through the vestibule. When emergency needs evacuation, personnel arrive at the elevator platform from the platform of registering one's residence through the vestibule, pass the step and arrive the platform of registering one's residence of next floor.

Preferably, the step (I) of compiling a corridor reconstruction scheme to ensure that the reconstruction construction process safety and the reconstructed corridor and stair meet the specific requirements of relevant building and fire fighting standard comprises the following steps:

a) the net width of the stair flight is not less than 1.10 m;

b) the step width of the stair is not less than 0.26m, and the height of the step is not more than 0.175 m;

c) the clear width of the landing is not less than the clear width of the stair section and is not less than 1.20 m;

d) the clear height of the upper and lower passageways of the stair platform is not less than 2.0m, and the clear height of the stair sections is not less than 2.2 m;

e) the height of the stair railing (handrail) is generally not less than 0.90 m;

f) the steps of each step should not exceed 18 steps.

Further explanation and description:

a corridor structure for realizing flat-floor entrance by adding an elevator in an existing building comprises a stair section, a cross beam, a horizontal corridor and a railing as shown in figures 4-7.

The specific arrangement mode of the cross beam comprises one of the following three modes:

type A: as shown in fig. 5, the cross beam is arranged at the connecting end of the horizontal corridor and the bench section, and is flush with the horizontal corridor in height;

type B: as shown in fig. 6, the cross beam is arranged at the connecting end of the horizontal corridor and the bench section and is arranged below the horizontal corridor;

type C: as shown in figure 7, the cross beam is arranged on the bench and positioned below the horizontal corridor, and a connecting piece is arranged in the vertical direction between the cross beam and the horizontal corridor.

Preferably, the guardrail device further comprises railings, and the railings are connected to the horizontal corridor and the ladder sections.

Preferably, regarding the modification scheme of the first floor, the cushion layer is generally cast in situ by concrete, the construction is completed before the installation of the stair sections, the cushion layer is a part of the stair sections, the width and the height of the stair are consistent with those of the newly added stair sections, and the width and the height of the stair are sequentially connected with the lower ends of the stair sections to form the whole stair sections;

preferably, the existing building is additionally provided with an elevator to realize a corridor reconstruction scheme for flat-layer entrance, and the cross beam, the corridor, the stair sections and the railings are all in a prefabricated structural part mode and are constructed in an assembly mode.

Preferably, when the construction is carried out in a hoisting mode in sequence, the bench sections are dismantled from top to bottom, and the horizontal corridor, the newly-added bench sections and the newly-added railings are hoisted in sequence from bottom to top, so that the construction organization is facilitated, the work efficiency is improved, and the time period that residents cannot enter and exit due to construction is shortened to the maximum extent.

Preferably, hoist and mount, it is the roof trompil of corridor, and the trompil size satisfies: the components such as the removed bench, the prefabricated horizontal corridor, the newly added bench, the newly added handrail and the like can be vertically lifted and transported to and from the positions.

Preferably, the connection is formed by combining the components into a whole in the form of bolt connection, welding connection and the like according to design and specification requirements, and the connection is in direct contact with the components, which means that the components are consistent in geometric position and are not required to be combined together.

Preferably, the corridor reconstruction construction time is completed by additionally arranging an elevator and an elevator platform, the elevator can run up and down, and after a horizontal corridor is installed, an elevator, the elevator platform, the horizontal corridor and a landing platform access passage can be formed, so that flat-floor landing is realized. After the newly-added bench is installed, the upper floor and the lower floor of the upper floor landing platform, the horizontal corridor, the elevator platform, the newly-added bench and the lower floor landing platform are in cascade passage, and the function of an emergency evacuation channel is exerted.

The invention discloses a modification method for a flat-floor entrance corridor of an existing building with an elevator, and particularly relates to a preferable assembly type construction method. The corridor structure is formed by combining a horizontal corridor, a stair section, a cross beam and a railing. By adopting scientific and reasonable construction organization, the problems that the additional land occupation is involved in other methods, the safety of the existing building structure is influenced, the resident can not enter and exit for a long time and the manufacturing cost is high can be effectively solved on the premise of ensuring the quality safety. According to the implementation of the scheme, the comprehensive aims of occupying zero extra land, not influencing the safety of the existing building structure, having relatively lowest manufacturing cost, controlling the entrance and exit time of a resident within 1-3 days and controlling the field assembly construction time within 3-5 days can be achieved, and the method has good economic and social benefits and good popularization value.

Drawings

Fig. 1 is a schematic view of a semi-floor entrance corridor structure in the background;

FIG. 2 is a schematic view of the structure of a sub-flat entrance corridor described in the background;

FIG. 3 is a schematic view of the structure of the flat-floor entrance corridor in the background;

FIG. 4 is an exploded view of the stair construction;

FIG. 5 is a combination view of the A-shaped stair structure;

FIG. 6 is a combination view of a B-shaped stair structure;

FIG. 7 is a combination view of a C-shaped stair structure;

fig. 8 is a sectional view of an original corridor section (balustrade omitted);

fig. 9 is a cross-sectional view (a), a front view (b), a railing view (c) and a perspective view (d) of a corridor reconstruction suitable for an a-type corridor structure;

fig. 10 is a cross-sectional view (a), a front view (B), a balustrade view (c) and a perspective view (d) of a corridor reconstruction suitable for a B-type corridor structure;

fig. 11 is a cross-sectional view (a), a front view (b), a balustrade view (C) and a perspective view (d) of a corridor reconstruction suitable for a C-type corridor structure;

fig. 12 is a schematic diagram of an existing building, which is provided with an elevator shaft and an elevator platform for elevator flat-layer entrance;

FIG. 13 is a view of vertical bracing and removal of the exterior walls of the corridor;

FIG. 14 is a view of the addition of steel cross beams;

FIG. 15 is a view with half of the bench removed and the intermediate deck;

FIG. 16 is a horizontal corridor diagram for installing steel structures;

FIG. 17 is a view showing the other half of the bench, the intermediate platform and the vertical supports removed;

FIG. 18 is a mounting steel structural bench;

FIG. 19 is a schematic view of a corridor for realizing addition of elevator flat floors to enter a home after installation of a handrail and modification;

FIG. 20 is a step diagram of a construction protocol;

FIG. 21 is a first floor corridor structural diagram;

FIG. 22 is a second floor corridor structural view;

FIG. 23 is a third view of the structure of the first floor corridor;

FIG. 24 is a first embodiment of a flat-level entrance stairway according to the present invention;

FIG. 25 is a second embodiment of the present invention;

wherein, 1 is horizontal vestibule, 2 is bench, 3 is railing, 4 is crossbeam, 5 is connecting piece, 6 is corridor outer wall, 7 is room, 8 is platform of registering one's residence, 9 is original bench, 10 is middle platform, 11 is elevator platform, 12 is elevator well, 13 is concrete cushion, 14 is reservation step, 15 is corridor, 16 is vertical support, 17 is existing building, 18 is door of registering one's residence.

Detailed Description

The detailed structure of the present invention will be further described with reference to the accompanying drawings and the detailed description.

As shown in fig. 9-11, a corridor structure for realizing flat-floor entrance by additionally arranging an elevator in an existing building comprises an elevator platform 11 and an entrance platform 8, wherein the corridor structure comprises N floors, wherein N is more than or equal to 2; the corridor structure of the (N-1) th floor further comprises a cross beam 4, a horizontal corridor 1 and a railing 3.

The A-type structure is characterized in that the cross beam 4 is arranged at the connecting end of the horizontal corridor 1 and the bench section 2, which is far away from the service platform, and is connected with the horizontal corridor 1 in a flush manner;

the B-type structure is characterized in that the cross beam 4 is arranged at the connecting end of the horizontal corridor 1 and the bench section 2, which is far away from the service platform, is positioned below the horizontal corridor 1 and is connected with the horizontal corridor 1 and the bench section 2;

the C-shaped structure is characterized in that the cross beam 4 is arranged below the middle ends of the horizontal corridor 1 and the bench sections 2, the cross beam 4 is directly connected with the lower portions of the bench sections 2, and the cross beam 4 is connected with the lower portion of the horizontal corridor 1 through a support piece 5;

the specific construction scheme is as follows, as shown in fig. 20, and fig. 12-19:

1. and structural calculation and scheme design are carried out on the corridor reconstruction according to the original building design drawing and the geological survey report, so that the corridor and the reconstruction construction process after the reconstruction is finished are ensured to meet the relevant standard requirements of building, fire fighting and construction.

2. The intermediate platform is temporarily and vertically supported, and the support system ensures the construction safety in the dismantling process through design and calculation.

3. And (5) removing the outer wall of the existing building corridor.

4. The space of the existing building corridor is enough, and the stair transformation carried out in the space can meet the requirements of building and fire-fighting standards. The existing building is provided with the beam or the ring beam on the floor layer, and the beam or the ring beam is reserved. The beam is detected, if the bearing capacity is insufficient, the beam is reinforced to meet the requirements, and the beam is suitable for an A-type structure. If no beam or ring beam is provided, the beam meeting the bearing capacity requirement is additionally arranged, and the structure is suitable for a B-type structure. The space of the corridor of the existing building is insufficient, so that when the gradient of the stair exceeds the requirements of building and fire-fighting standards by utilizing the existing cross beam or ring beam, the existing cross beam or ring beam needs to be cut off, the height of the newly added cross beam is reduced, and the gradient of the stair meets the requirements of the standards. At the moment, the corridor and the bench can extend outwards of the building and are suitable for C-shaped structures.

5. The beam arrangement position should satisfy the following requirements: the horizontal corridor (including the pavement thickness) surface erected above is flush with the landing platform and the elevator platform surface, and the upper clearance is not less than 2 m.

6. And (5) removing the upper half step and the middle half platform of the existing building from top to bottom and lifting the stair out of the corridor.

7. And hoisting the assembled corridor from bottom to top. One end of the corridor is connected with the entrance platform, and the other end of the corridor is connected with the cross beam and is connected with the elevator platform in the same direction. The elevator platform, the corridor and the service platform are adjusted to be level and fixed firmly, the handrail is installed, an access passage formed by the elevator, the elevator platform, the corridor and the service platform is formed, and the flat floor service is realized.

8. And (5) removing the other half of the stair and the half of the middle platform of the existing building from top to bottom and lifting the stair out of the corridor. Generally, the half-range stair sections and the middle platform need not to be dismantled.

9. And hoisting the assembled ladder section from bottom to top. One end of the ladder section is connected with the platform for entering a house, the other end of the ladder section is connected with the cross beam of the adjacent floor and is connected with the elevator platform in the same direction, the fixing is firm, the handrail is installed, the ladder passage of the upper floor and the lower floor is formed, and the emergency evacuation function is realized.

10. And carrying out spraying construction of anticorrosive and fireproof paint on the steel structure.

11. And evaluating, checking and accepting the transformed project, and delivering for use.

Additional description:

1. the appropriate type of corridor structure can be selected according to the existing building conditions in combination with the requirements of the inhabitants, and the patent application text exemplifies A, B, C three types (shown in fig. 5-7), but is not limited to the three types.

2. According to the difference of stair forms in the existing building corridor, the application text exemplifies a flat-layer house-entering method formed by the assembly and connection of a corridor, a stair section, a cross beam and a railing with the existing building house-entering platform and the elevator platform additionally provided with an elevator under the condition. The method can be applied to other types of corridors, and only relates to the selection of whether the corridor is arranged on the left side or the right side of the corridor, and the upper end of the stair section is connected with an elevator platform or a landing, as shown in fig. 24 and 25, and still belongs to the category related to the method. The present patent application text is not to be construed as limiting to space.

3. The original stair structure is preferably reserved in the first stair section modification, the stability of the existing building structure is facilitated, and the manufacturing cost is relatively reduced. The method needs to consider the reasonable connection between the next half of the bench and the newly added bench, so the design of the newly added bench needs to be adjusted locally. Meanwhile, the following methods can be selected:

the method comprises the following steps that (I) an original stair structure is kept unchanged (as shown in figure 8), a concrete cushion layer (13) is additionally arranged on the lower half range of the original stair structure, and the lower end of a newly added stair section (2) from a first floor to a second floor is reasonably connected with the concrete cushion layer (13) (as shown in figure 23);

secondly, all the stair sections and the middle platforms of the first floor are dismantled, and the method is implemented according to the installation method of the stair sections of other floors (as shown in figure 21);

and (III) dismantling the lower half bench, reserving the whole middle platform and the upper half bench, and implementing the newly added bench according to the installation method of the benches of other floors (as shown in figure 22).

The above description is for the purpose of illustrating the present invention and is not intended to limit the scope of the present invention, and any person skilled in the art can substitute or change the technical solution of the present invention and its conception within the technical scope of the present invention, and the technical solution and the concept of the present invention are also intended to be covered by the scope of the claims of the present invention.

Claims

1. A corridor reconstruction method for realizing flat-floor entrance by adding an elevator in an existing building is characterized by comprising the following steps:

step two: a temporary vertical support is additionally arranged on the middle platform;

the A-shaped structure reserves a cross beam or a reinforcing ring beam; the B-type structure is additionally provided with a cross beam according to the design requirement; dismantling the cross beam or the ring beam by the C-shaped structure; the corridor structure comprises an elevator platform (11) and a service platform (8), and the corridor structure comprises N layers, wherein N is more than or equal to 2; the corridor structure of the (N-1) th floor further comprises a stair section (2), a cross beam (4) and a horizontal corridor (1); the horizontal corridor (1) is horizontally arranged, one end of the horizontal corridor (1) is connected with the cross beam and is connected with the elevator platform (11) in the same direction, and the other end of the horizontal corridor (1) is connected with the entrance platform (8); one end of the ladder section (2) is connected with the beam and is in direct connection with the elevator platform (11) and the horizontal corridor (1), and the other end of the ladder section is connected with the entrance platform of the adjacent floor; wherein:

the crossbeam (4) is arranged at the connecting end of the horizontal corridor (1) and the bench section (2) far away from the service platform and is connected with the horizontal corridor (1) in a flush manner;

the beam (4) is arranged at the connecting end of the horizontal corridor (1) and the bench section (2) far away from the service platform, is positioned below the horizontal corridor (1), and is connected with the horizontal corridor (1) and the bench section (2);

the cross beam (4) is arranged below the middle ends of the horizontal corridor (1) and the bench sections (2) in the C-shaped structure, the cross beam (4) is directly connected with the lower portions of the bench sections (2), and the cross beam (4) is connected with the lower portions of the horizontal corridor (1) through the supporting pieces (5);

step four: newly adding a beam according to the design requirement according to the corridor structure selected in the step three;

step five: sequentially dismantling the half-width bench and the middle platform, and sequentially installing the horizontal vestibule; the horizontal corridor (1) is horizontally arranged, one end of the horizontal corridor is connected with the service platform (8), and the other end of the horizontal corridor is connected with the cross beam (4) and is connected with the elevator platform (11) in the same direction; the elevator, the elevator platform, the horizontal corridor and the entrance platform form an entrance and exit channel to realize flat-layer entrance;

step six, dismantling the other half of the bench, the middle platform and the temporary supports in sequence, and installing the bench in sequence; one end of the ladder section (2) is connected with the landing (8), and the other end is connected with the adjacent floor beam (4) and is in direct connection with the elevator platform (11), so that the stair traffic of upper and lower floors is realized;

step seven: adjust elevator platform, vestibule, platform of registering one's residence to the parallel and level and fixed firm, adjust the bench and fixed firm, installation railing (3).

2. The stair reconstruction method for achieving flat-floor entrance by adding the elevator to the existing building according to claim 1, wherein the step (I) of compiling a corridor reconstruction scheme is characterized in that the step (I) of ensuring that the reconstructed corridor and the reconstructed stair meet the specific requirements of relevant building and fire fighting standard in the reconstruction construction process comprises the following steps of:

a) the net width of the stair flight is not less than 1.10 m;

f) the steps of each step should not exceed 18 steps.

3. The stair reconstruction method for achieving flat-floor entrance of the existing building with the added elevator according to claim 1, wherein regarding the first-floor reconstruction scheme, the scheme is selected from the following modes A, B and C:

in the mode A, the original stair structure is removed, and the stair structure is added to be identical to the corridor structure of the (N-1) th floor in claim 1;

in the mode B, the lower half bench is dismantled, the whole middle platform and the upper half bench are reserved, and a stair structure is added to be identical to the corridor structure of the layer N-1 in the claim 1;

mode C remains former stair structure unchangeable, and adds the bed course at half range bench under former stair structure, and bench (2) lower extreme and bed course (13) are in the same direction as connecing, form whole section bench.

4. A staircase reconstruction method for realizing flat floor entrance by adding elevator in the existing building as claimed in claim 3, characterized in that, regarding the reconstruction scheme of the first floor, the cushion layer (13) is cast in situ by concrete, the construction is completed before the installation of the bench, the cushion layer is a part of the bench, the width and height of the step are the same as those of the newly added bench, and the cushion layer is connected with the lower end of the bench (2) in the same direction to form the whole bench.

5. A method for improving stairs of an existing building with an added elevator to realize flat-floor entrance as claimed in any one of claims 1-4, wherein the cross beam (4) is of a precast concrete structure or a precast steel structure.