Prefabricated lightweight aggregate concrete additionally-built elevator shaft and foundation settlement control method thereof

Abstract

The invention discloses a prefabricated lightweight aggregate concrete additionally-built elevator shaft and a foundation settlement control method thereof.The prefabricated lightweight aggregate concrete additionally-built elevator shaft comprises a foundation module, a standard knot module, a corridor module and a top layer module; the foundation settlement control method comprises the steps of collection of calculation parameters, calculation of wind-induced cyclic stress, calculation of foundation differential settlement and control of differential settlement. A standardized prefabricated module is adopted, integrated prefabrication of an enclosure wall system, a structural stress component and an outer vertical face decoration layer in a factory is achieved, and the advantages of building style and appearance coordination, light weight and high adaptability are achieved; the quantitative and verifiable wind-induced foundation differential settlement prediction and control method is provided, and effective control over the foundation differential settlement risk under the main wind direction load is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building foundation engineering and relates to a prefabricated light aggregate concrete added elevator shaft and a foundation settlement control method thereof. BACKGROUND

[0002] The intensification of population aging, the increasing demand of residents for the improvement of living quality, and the promotion of barrier-free environment construction make the installation of elevators in old residential buildings an important livelihood project. However, the mainstream structure of the added elevator shaft in the current old residential buildings still has many defects that cannot be ignored, which are difficult to meet the actual demand, including: 1) low efficiency of cast-in-place process: cast-in-place reinforced concrete structure needs to complete multiple processes such as formwork, pouring, and curing in turn, and then needs to separately carry out the construction of enclosing wall, waterproofing, and decoration, which not only makes the process complicated, but also leads to a long construction period; at the same time, the pouring of concrete needs to coordinate the supply of ready-mixed concrete, but the small amount of concrete required for the installation of elevators at a time easily causes low supply efficiency, and the curing period interrupts the continuity of construction, further prolongs the construction period, and greatly interferes with the daily life of residents in old residential buildings; 2) defects of steel frame structure: although the steel frame structure is superior to cast-in-place concrete in terms of construction convenience, it has problems of long-term use hidden dangers and insufficient adaptability: steel is easily corroded by the environment, and the old residential buildings generally face the status of imperfect property maintenance system and difficult maintenance fund raising, which leads to the risk of corrosion and failure of steel structure in long-term use and forms a safety risk; in addition, the steel structure elevator adopts curtain wall as the enclosing system, which not only has a single facade style and high cost, is difficult to coordinate with the original building style, and has a broken risk of glass curtain wall, but also has high maintenance cost, and if the maintenance is missing, it is easy to cause safety accidents.

[0003] More importantly, the old residential buildings generally have the layout characteristics of dense buildings and small building spacing, which leads to the formation of frequent main wind direction load due to the blockage of wind flow by buildings. When the prefabricated assembly elevator shaft is put into use, the continuous main wind direction load will produce a long-term lateral force on the shaft structure, which will cause the shaft structure to be stressed on one side for a long time, and then cause local stress concentration of the foundation, especially for the areas with shallow foundation or general soil conditions, which is easy to cause uneven settlement of the foundation. Part of the shaft structure is separately arranged with the main structure and has no connection, so that the shaft becomes a high-rise structure and is more sensitive to wind load, and the lateral deformation is more significant when it is independently subjected to wind. In addition, the prefabricated assembly elevator shaft relies on precise connection modes such as buckle connection and structural adhesive sealing, and the settlement difference will destroy the stress balance of the buckle joint and tear the structural adhesive sealing layer, which will cause the failure of the sealing of the shaft and the decrease of the structural stiffness, and directly threaten the safety of passing.

[0004] In summary, the existing elevator shaft structure has the problems of complicated process, high maintenance cost, poor style coordination, and cannot cope with the risk of foundation settlement caused by the main wind direction load in the old and dense community. Therefore, there is an urgent need for a prefabricated lightweight aggregate concrete elevator shaft technology that has high assembly rate, low maintenance cost, style adaptability, and can control the foundation settlement under the main wind direction load. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a modular high-strength steel reinforced lightweight aggregate concrete building surface integrated composite elevator shaft that is safe and reliable, lightweight, convenient to transport and install, saves construction period, has low cost, simple construction process, reduces construction waste, stable construction quality, and good durability, and the outer facade style can be coordinated with the building.

[0006] The prefabricated lightweight aggregate concrete elevator shaft includes a foundation module, a standard module, a corridor module and a top module.

[0007] The foundation module includes a reinforced concrete bottom plate and a shaft side wall from the bottom surface of the foundation to the ground elevation of the first floor, which is made of conventional cast-in-place reinforced concrete; a buckle connecting sleeve reliably connected with the internal longitudinal steel bars is pre-embedded at the top end of the four corner parts of the shaft side wall, for butt joint with the standard module above;

[0008] The standard module is a tetrahedron structure with a door opening, including a surrounding wall system and a stress structure; the stress structure is composed of four corner-shaped columns, floor beams, interlayer structural beams and corbels; the lower end of the shaped column is pre-embedded with a buckle connecting rod, and the upper end is pre-embedded with a buckle connecting sleeve; the upper and lower modules are connected by buckle insertion and sealed with structural glue; the corbel is pre-embedded with a buckle connecting sleeve for corridor module installation. The surrounding wall system is a sandwich lightweight aggregate reinforced concrete wall with a total thickness of 180mm or 200mm; the standard module is prefabricated in the factory, and the outer decorative layer can be coordinated with the building facade; the outer decorative layer adopts one of paint, tile, water-washed stone or real stone paint, and is integrated with the lightweight aggregate concrete wall in the factory.

[0009] The corridor module includes a fence, a corridor floor and a floor drain; the fence serves as a structural beam and a handrail; one end of the corridor floor is provided with a buckle connecting rod for plug-in connection with the sleeve on the corbel of the same standard module, and the joint is sealed with structural glue; the other end is used for connecting with the original building structure.

[0010] The top layer module is integrated with a special-shaped column, a structural beam, a retaining wall system, a top plate and a pre-buried lifting hook; the special-shaped column is provided with a buckle connecting rod at the lower end, is connected with a lower standard section module, and the contact surface is sealed by structural glue; the thickness of the top plate is determined by calculation and is not less than 200mm, and the lifting hook is pre-buried according to the parameters of the elevator.

[0011] Preferably, the total thickness of the sandwiched lightweight aggregate reinforced concrete wall is 180mm or 200mm; a 60mm thick polystyrene board is embedded in the middle, and 60mm or 80mm thick lightweight aggregate concrete layers are arranged on both sides; the wall is provided with horizontal and vertical distribution steel bars with a model of HRB400, a diameter of 8mm and a spacing of 200mm, and the horizontal steel bars are anchored in the special-shaped column; the strength grade of the lightweight aggregate concrete is not less than LC25, and the unit weight is not more than 16kN / m 3 The lightweight coarse aggregate, ordinary sand, cementing material, additive and water are used to prepare the lightweight aggregate concrete.

[0012] Preferably, the L-shaped steel plate is fixed on the original building through the rear embedded part, the corridor floor is overlapped on the steel plate, the overlapping length is not less than 150mm, and the joint is sealed by structural glue; when the rear embedded part cannot be arranged on the original building, a structure column is arranged on the corridor module, the buckle connecting sleeve and the connecting rod are arranged at the upper end and the lower end of the structure column respectively, the upper and lower corridor modules are connected through the buckle, and the corridor foundation module is arranged at the bottom to provide support.

[0013] Preferably, the present application also provides a construction method of the prefabricated lightweight aggregate concrete additional building elevator shaft, which comprises the following steps:

[0014] S101, site preparation and foundation design: first, the construction site is leveled, and the foundation pit is excavated according to the design requirements; the foundation pit support design and foundation form selection are carried out in combination with the site geological survey data;

[0015] S102, cast-in-place construction of the foundation module: the steel reinforcement concrete bottom plate and the shaft side wall steel reinforcement are bound, the formwork is supported, and the concrete is poured; the buckle connecting sleeve which can be reliably connected with the internal longitudinal steel reinforcement is accurately pre-buried at the top of the four corners of the shaft side wall, and the position accuracy is ensured to meet the docking requirements of the upper module;

[0016] S103, hoisting and connection of the standard section module: structural glue is evenly applied at the connecting sleeve interface at the top of the shaft side wall of the foundation module; the buckle connecting rod at the bottom of the prefabricated standard section module is aligned with the sleeve position, hoisted to the predetermined installation height by using hoisting equipment, slowly lowered to make the buckle connecting rod inserted into the reserved connecting sleeve, and the fixing with the foundation module is completed;

[0017] S104, Corridor module installation: If the original building structure allows, post-embedded parts are constructed on the original building structure beam of the corresponding floor to reliably fix and extend the L-shaped steel plate; the corridor module is hoisted to the installation position, the reserved buckle connecting rod at one end is inserted into the buckle connection sleeve on the standard section module bracket, and the other end is lapped on the L-shaped steel plate, the contact gap is sealed with structural adhesive, and the fixing is completed; if the original building cannot set post-embedded parts, a corridor module with a structural column is used: structural adhesive is applied to the upper end of the structural column, the reserved buckle connecting rod at the bottom of the upper structural column is inserted into the reserved connecting sleeve of the lower corridor module, and the upper and lower corridor modules are fixed by buckle connection;

[0018] S105, Layered cycle installation: structural adhesive is uniformly applied to the top end of the installed standard section module, the last layer of the standard section module is continued to be hoisted and fixed according to the method described in step S103, and the installation of the corridor module of the corresponding floor is completed according to step S104 at the same time, until the designed height is reached;

[0019] S106, Top module installation: when the installation of the last layer of the standard section module is completed, structural adhesive is uniformly applied to the top end thereof; the buckle connecting rod at the bottom of the top module is aligned with the reserved connecting sleeve of the lower standard section module, hoisted to the installation position and inserted into the sleeve, and fixed by buckle connection and structural adhesive sealing, thus the installation of the elevator shaft main body structure is completed.

[0020] Preferably, according to the site geological conditions and site flatness, if the conditions allow, the foundation module and the corridor foundation module can be precast in the factory: the thickness of the bottom steel reinforcement protective layer is set to 70 mm during precasting, and after precasting is completed, the precast foundation module is transported to the site for direct hoisting and installation, without the need for additional cast-in-place cushion, so as to improve the construction efficiency.

[0021] The foundation settlement control method of the precast lightweight aggregate concrete added elevator shaft, comprising:

[0022] S201, Collection of calculation parameters:

[0023] The wind load parameters, foundation soil parameters and shaft structure parameters of the cell are collected; the wind load parameters include annual equivalent wind vibration cycle number N y , azimuth angle θ of dominant wind direction, wind load amplitude W0 along the height of the shaft, wind pressure height variation coefficient β z (z) at height z, wind vibration coefficient β s and wind load time history curve along the height of the shaft; the annual equivalent wind vibration cycle number N y needs to be corrected in combination with the regional wind environment, i.e. N y =N y0 ·K wind , wherein the annual equivalent wind vibration cycle number N y∈ [150,300] times / year, K wind is the regional correction coefficient, which is determined according to the China Building Climate Regionalization Map; the wind load time history curve along the shaft height is calculated by the small area CFD wind field model, and the ground roughness coefficient of the actual topography of the small area, the inlet wind speed and the outlet free flow parameters need to be input during the calculation; the ground soil body parameters include compression modulus E i , soil cyclic deformation parameters m1, m2 and m3; the shaft structure parameters include the total height H of the elevator shaft, the plane length B1 and width B2, the foundation bottom area A g , the structure basic frequency f1, the prefabricated module mass M, the shear stiffness K c of the buckle connection and the tensile stiffness K s of the structural adhesive;

[0024] S202, wind-induced cyclic stress calculation:

[0025] According to the non-uniform distribution characteristics of the wind load along the height, the calculation expression of the standard value of the fluctuating wind pressure along the height of the shaft is W k (z)=β z (z)·β s ·W0; the wind-induced overturning moment M wind of the base satisfies the following expression:

[0026]

[0027] The base horizontal shear V wind satisfies the following expression:

[0028]

[0029] The base horizontal shear V wind causes the base to generate a horizontal cyclic shear stress τ cyc , which satisfies the following expression:

[0030]

[0031] Wherein, β t is the horizontal stress concentration coefficient, and β t =1.2;

[0032] The wind-induced base additional pressure q j of the jth corner point satisfies the following expression:

[0033]

[0034] Wherein, d j is the distance from the jth corner point to the centroid of the foundation; I g is the moment of inertia of the foundation; η jis the wind pressure weight coefficient of the jth corner point, and satisfies the following expression:

[0035]

[0036] wherein, is the corner azimuth of the jth corner point; and θ is the azimuth of the dominant wind direction;

[0037] S203, calculation of uneven settlement of foundation:

[0038] When the uneven settlement of foundation is mainly controlled by wind-induced base additional pressure, according to the hysteresis effect of soil under cyclic loading, the cyclic cumulative settlement ε of the ith layer of foundation soil under the jth corner point is ij satisfies the following expression:

[0039]

[0040] wherein, m1, m2 and m3 are all cyclic deformation parameters of soil, which are calibrated by dynamic triaxial test; σ v is the effective overburden pressure; N cycle is the number of cyclic loadings;

[0041] The wind-induced cyclic cumulative settlement S of the jth corner point is j satisfies the following expression:

[0042]

[0043] wherein, h i is the thickness of the ith layer of foundation soil;

[0044] The uneven settlement ΔS satisfies the following expression:

[0045] ΔS = max(S j ) - min(S j )

[0046] wherein, max(S j ) and min(S j ) are the maximum value and the minimum value of the wind-induced cyclic cumulative settlement S j respectively;

[0047] S204, control of uneven settlement:

[0048] According to the characteristics of shaft modularization connection and the requirements of specifications, the allowable value of uneven settlement [ΔS] is determined, as shown in the following formula:

[0049]

[0050] Wherein, the uneven settlement allowable value [AS] should not exceed the fitting gap 2mm of the buckle connecting rod and the connecting sleeve, avoiding the stress concentration of the node; δ g is the allowable deviation value of the verticality of the elevator guide rail, taken from the Elevator Engineering Construction Quality Acceptance Standard g is 1.5mm, avoiding the uneven settlement of the foundation leading to the deviation of the verticality of the guide rail and further affecting the operation safety;

[0051] When AS < [AS], it is predicted that the uneven settlement of the foundation meets the requirements, and the foundation design scheme is feasible; when AS ≥ [AS], it is predicted that the settlement does not meet the requirements, and reinforcement measures need to be taken; the reinforcement measures prefer to expand the foundation bottom area A g , and the calculation process of steps S201 to S204 is re-executed until the requirement of AS < [AS] is met.

[0052] In summary, compared with the prior art, the beneficial effects of the present application are: in view of the problems of the existing elevator shaft structure, such as complicated process, high maintenance cost, poor style coordination, and unable to cope with the foundation settlement caused by the load of the main wind direction of the old dense community, the present application proposes a prefabricated lightweight aggregate concrete added elevator shaft and a foundation settlement control method. The prefabricated lightweight aggregate concrete added elevator shaft includes a foundation module, a standard section module, a corridor module and a top module. The foundation settlement control method includes collection of calculation parameters, calculation of wind-induced cyclic stress, calculation of uneven settlement of foundation and control of uneven settlement, which realizes the following breakthrough improvements:

[0053] 1) Improvement of high assembly rate and construction efficiency: standardized prefabricated modules are used to realize the integrated prefabrication of the enclosure wall system, structural stress components and exterior decoration layer in the factory, so that only hoisting, buckle insertion and structure glue sealing processes are needed on site, completely abandoning the long processes of formwork, pouring and curing required by cast-in-place concrete and the secondary construction of steel structure enclosure system, significantly improving the construction efficiency and reducing the interference with the daily life of community residents;

[0054] 2) Effective control of foundation settlement risk under the load of the main wind direction: a quantitative and verifiable wind-induced foundation uneven settlement prediction and control method is proposed, which combines the unique wind environment characteristics of old communities and the cyclic characteristics of foundation soil, quantitatively calculates the wind-induced foundation uneven settlement, and formulates control standards according to the limit of the buckle fitting gap and the deviation requirement of the verticality of the elevator guide rail, to ensure that the uneven settlement of the foundation does not damage the precise connecting node and affect the operation safety of the elevator when used for a long time in windy areas;

[0055] 3) Architectural style coordination advantage: The outer facade of the prefabricated light aggregate concrete added elevator shaft of the application can flexibly select the facing materials and textures coordinated with the original building height when prefabricated in the factory, realizes seamless integration into the existing building group, and avoids the problem of the style of the steel structure curtain wall being conspicuous;

[0056] 4) Lightweight advantage: The application of prefabricated light aggregate concrete makes the weight of the standardized prefabricated module significantly lower than that of the ordinary concrete module with the same strength, reduces the transportation and hoisting difficulty and cost, and reduces the load demand on the foundation;

[0057] 5) Strong adaptability: The foundation form and the connection mode of the corridor and the original building can be adjusted according to the site conditions, and the adaptability to the complex building environment of the old community is improved. BRIEF DESCRIPTION OF DRAWINGS

[0058] Figure 1 It is a first schematic diagram of the three-dimensional effect of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0059] Figure 1a It is a second schematic diagram of the three-dimensional effect of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0060] Figure 2 It is a three-dimensional schematic diagram of the foundation module of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0061] Figure 2a It is a three-dimensional schematic diagram of the corridor foundation module of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0062] Figure 3 It is a three-dimensional schematic diagram of the standard section module of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0063] Figure 4 It is a three-dimensional schematic diagram of the buckle type connection node of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0064] Figure 5 It is a three-dimensional schematic diagram of the sandwich light aggregate reinforced concrete wall of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0065] Figure 6 It is a three-dimensional schematic diagram of the corridor module of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0066] Figure 6a It is a three-dimensional schematic diagram of the corridor module with a structural column of the prefabricated light aggregate concrete added elevator shaft of the embodiment of the application;

[0067] Figure 7A three-dimensional schematic diagram of a prefabricated lightweight aggregate concrete building elevator shaft L-shaped steel plate embedded part detail of an embodiment of the present application;

[0068] Figure 8 A three-dimensional schematic diagram of a prefabricated lightweight aggregate concrete building elevator shaft upper and lower layer module connection node detail of an embodiment of the present application;

[0069] Figure 9 A three-dimensional schematic diagram of a prefabricated lightweight aggregate concrete building elevator shaft top layer module of an embodiment of the present application;

[0070] Figure 10 A flowchart of a foundation settlement control method for a prefabricated lightweight aggregate concrete building elevator shaft of an embodiment of the present application.

[0071] The figure identification: 1 - base module; 1a - corridor base module; 2 - standard section module; 3 - corridor module; 3a - corridor module with structural column; 4 - top layer module; 5 - reinforced concrete bottom plate; 6 - elevator shaft side wall; 7 - buckle connection sleeve; 8 - special-shaped column; 9 - floor beam; 10 - interlayer structural beam; 11 - corbel; 12 - buckle connecting rod; 13 - enclosure wall system; 14 - vertical reinforcement; 15 - lightweight aggregate polystyrene board; 16 - horizontal distribution reinforcement; 17 - enclosure wall vertical reinforcement; 18 - panel; 19 - corridor floor; 20 - floor drain; 21 - rear embedded part; 22 - L-shaped steel plate; 23 - anchor bolt; 24 - stiffener; 25 - structural adhesive; 26 - buckle connection node; 27 - top plate; 28 - lifting hook; 29 - structural column; 30 - corridor base bottom plate. DETAILED DESCRIPTION

[0072] The specific embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments given here are only for illustration and explanation of the present application, and cannot be used to limit the present application.

[0073] The first aspect of the present application discloses a prefabricated lightweight aggregate concrete building elevator shaft as shown in Figures 1-9 The prefabricated lightweight aggregate concrete building elevator shaft comprises a base module (1), a standard section module (2), a corridor module (3), and a top layer module (4). As shown in Figure 2 The base module (1) comprises a base bottom plate (5) and a shaft side wall (6), and a buckle connection sleeve (7) is reserved at a corresponding position of the shaft side wall. As shown in Figure 3 The standard section module (2) comprises four corner special-shaped columns (8), a floor beam (9), an interlayer structural beam (10), a corbel (11), and the like, a sleeve (7) is reserved at the upper end of the special-shaped column (8), and a buckle connecting rod (12) is reserved at the lower end of the special-shaped column (8). A buckle connection sleeve (7) is reserved at the upper end of the corbel. As shown in Figure 9 The top layer module (4) comprises a special-shaped column (8), a floor beam (9), an enclosure wall system (13), a top plate (27), and a lifting hook (28).Figure 8 As shown, the basic module (1), standard section module (2), and top layer module (4) are reliably connected to each other through snap-fit ​​connections and sealing with structural adhesive (25). Detailed snap-fit ​​connections are shown below. Figure 4 As shown.

[0074] like Figure 5 As shown, the retaining wall is made of lightweight aggregate reinforced concrete with polystyrene board (15) embedded in the middle, which effectively reduces the structural weight.

[0075] like Figure 6 As shown, the connecting corridor module (3) includes a balustrade (18), a connecting corridor floor slab (19), a pre-installed snap-fit ​​connecting rod (12), and a floor drain. Figure 7 The original building shown is connected to the embedded part (21) by anchor bolts (23), and the L-shaped steel plate (22) extends out.

[0076] When it is not possible to install embedded parts in the original building, a connecting corridor module (3a) with structural columns is adopted. The overall implementation plan is as follows: Figure 1a As shown. Figure 2a The bottom of the connecting corridor is shown as a basic module (1a). The connecting corridor module (3a) with structural columns is shown below. Figure 6a As shown, two structural columns (29) are added on both sides of the connecting corridor.

[0077] In specific implementation, the construction method for adding elevator shafts using precast lightweight aggregate concrete includes the following steps:

[0078] S101. Site preparation and foundation design: First, the construction site is leveled and the foundation pit is excavated according to the design requirements; the foundation pit support design and foundation type selection are carried out in combination with the site geological survey data.

[0079] S102. Cast-in-place construction of basic modules: Tie the reinforced concrete base slab and the side wall reinforcement of the shaft, and pour concrete after setting up the formwork; accurately pre-embed the snap-fit ​​connecting sleeves that are reliably connected to the internal longitudinal reinforcement at the top of the four corners of the shaft side wall to ensure their positional accuracy to meet the docking requirements of the upper module.

[0080] S103. Standard Section Module Lifting and Connection: Apply structural adhesive evenly to the connecting sleeve interface at the top of the shaft sidewall of the foundation module; align the buckle rod at the bottom of the prefabricated standard section module with the sleeve position, use lifting equipment to lift it to the predetermined installation height, and slowly lower it so that the buckle rod is inserted into the reserved connecting sleeve to complete the fixing with the foundation module;

[0081] S104. Installation of connecting corridor modules: If the original building structure allows, install post-embedded parts on the structural beams of the corresponding floors of the original building to reliably fix and extend the L-shaped steel plate; hoist the connecting corridor module to the installation position, align and insert the reserved buckle connecting rod at one end with the buckle connecting sleeve on the standard section module bracket, and overlap the other end on the L-shaped steel plate. Seal the gaps at the contact surfaces with structural adhesive to complete the fixation; if the original building cannot install post-embedded parts, use a connecting corridor module with structural columns: apply structural adhesive to the upper end of the structural column, align and insert the reserved buckle connecting rod at the bottom of the upper structural column with the reserved connecting sleeve of the lower connecting corridor module, and fix the upper and lower connecting corridor modules through buckle connection;

[0082] S105. Layered Cyclic Installation: Apply structural adhesive evenly to the top of the installed standard section module, continue to hoist and fix the standard section module of the next layer according to the method described in step S103, and simultaneously complete the installation of the connecting corridor module of the corresponding floor according to step S104 until the design height is reached.

[0083] S106. Top-level module installation: After the last standard section module is installed, apply structural adhesive evenly to its top; align the buckle connecting rod at the bottom of the top-level module with the reserved connecting sleeve of the lower standard section module, hoist it to the installation position and insert the sleeve, and fix it by buckle connection and sealing with structural adhesive. At this point, the main structure of the elevator shaft is installed.

[0084] In practice, depending on the site's geological conditions and flatness, if conditions permit, the foundation modules and connecting corridor foundation modules can be prefabricated in the factory: during prefabrication, the thickness of the bottom steel reinforcement protective layer is set to 70mm. After prefabrication, the modules are transported to the site for direct hoisting and installation, without the need for additional cast-in-place pads, thus improving construction efficiency.

[0085] The second aspect of this application discloses, as follows: Figure 10 The method for controlling foundation settlement of precast lightweight aggregate concrete elevator shafts, as shown, includes the following steps:

[0086] S201. Collection of calculation parameters: Collect wind load parameters, foundation soil parameters, and shaft structure parameters of the residential area; the wind load parameters include the annual equivalent wind vibration cycle number N. y The azimuth angle θ of the prevailing wind direction, the wind load amplitude W0 along the shaft height, and the wind pressure height variation coefficient β at height z. z (z), wind vibration coefficient β s Wind load time history curves along shaft height; annual equivalent wind vibration cycles N obtained from meteorological data statistics. y It needs to be adjusted based on the regional wind environment, i.e., N y =N y0 ·K wind Among them, the annual equivalent wind vibration cycle number N of a typical old residential areay ∈[150,300] times / year, K wind is the regional correction coefficient, which is determined according to the China Building Climate Regionalization Map; in the specific implementation, the annual equivalent wind vibration cycle number N y = 200 times / year, the regional correction coefficient K wind is 1.1, and N y is calculated to be 220 times / year; the wind load time history curve along the shaft height is calculated by a small district CFD wind field model, and the ground roughness coefficient of the actual topography of the small district, the inlet wind speed and the outlet free flow parameters need to be input during the calculation; the ground soil body parameters include the compression modulus E i , soil cyclic deformation parameters m1, m2 and m3; the shaft structure parameters include the total height H of the elevator shaft, the plane length B1 and width B2, the foundation bottom area A g , the structure basic frequency f1, the prefabricated module mass M, the shear stiffness K c of the buckle connection and the tensile stiffness K s of the structural adhesive.

[0087] S202, wind-induced cyclic stress calculation: according to the non-uniform distribution characteristics of the wind load along the height, the calculation expression of the fluctuating wind pressure standard value along the shaft height is W k (z) = β z (z)·β s ·W0; the base wind-induced overturning moment M wind satisfies the following expression:

[0088]

[0089] The base horizontal shear V wind satisfies the following expression:

[0090]

[0091] In the specific implementation, the base wind-induced overturning moment M wind is calculated to be 125 kN·m, and the base horizontal shear V wind is 32 kN;

[0092] The base horizontal shear V wind causes the base to generate a horizontal cyclic shear stress τ cyc , which satisfies the following expression:

[0093]

[0094] Wherein, β t is a horizontal stress concentration coefficient, and β t = 1.2;

[0095] Under typical conditions, the wind pressure weight coefficient ηj satisfies the following expression:

[0096]

[0097] wherein, is the corner azimuth angle of the jth corner; θ is the azimuth angle of the dominant wind direction; η is the wind pressure weight coefficient j reflects the different influence degree of the dominant wind direction load on each corner under the condition of specific elevator shaft geometry.

[0098] the wind-induced base additional pressure q of the jth corner j satisfies the following expression:

[0099]

[0100] wherein, d j is the distance from the jth corner to the centroid of the foundation; I g is the moment of inertia of the foundation.

[0101] S203, calculation of uneven settlement of foundation: when the uneven settlement of foundation is mainly controlled by the wind-induced base additional pressure, according to the hysteresis effect of soil under cyclic load, the cyclic cumulative settlement ε of the ith layer of foundation soil under the jth corner ij satisfies the following expression:

[0102]

[0103] wherein, m1, m2 and m3 are all cyclic deformation parameters of soil, which are calibrated through dynamic triaxial test, and in the specific implementation, m1=0.002, m2=0.6 and m3=0.2 are taken for silty clay layer; σ v is the effective overburden pressure; N cycle is the number of cyclic loads;

[0104] the wind-induced cyclic cumulative settlement S of the jth corner j satisfies the following expression:

[0105]

[0106] wherein, h i is the thickness of the ith layer of foundation soil;

[0107] the uneven settlement ΔS satisfies the following expression:

[0108]

[0109] wherein, max(S j ) and min(S j ) are the wind-induced cyclic cumulative settlement S jthe maximum and minimum values of S j ) and min(S j ) are 10 mm and 6.5 mm respectively, and the uneven settlement ΔS is 3.5 mm.

[0110] S204, control of uneven settlement: according to the characteristics of the hoistway modular connection and the specification requirements, the allowable value of uneven settlement [ΔS] is determined, as shown in the following formula:

[0111]

[0112] wherein the allowable value of uneven settlement [ΔS] should not exceed the fitting gap 2 mm of the buckle connecting rod and the connecting sleeve, so as to avoid stress concentration of the node; δ g is the allowable deviation value of the verticality of the elevator guide rail, according to the “Elevator Engineering Construction Quality Acceptance Standard”, δ g is 1.5 mm, so as to avoid the deviation of the verticality of the guide rail caused by the uneven settlement of the foundation, thereby affecting the running safety;

[0113] It is judged that ΔS = 3.5 mm ≥ [ΔS] = 0.208 mm, the predicted settlement does not meet the requirements, and reinforcing measures need to be taken, the reinforcing measures prefer to expand the foundation bottom area A g , and the calculation process of steps S201 to S204 is re-executed until the requirement of ΔS < [ΔS] is met.

[0114] The above is one or more embodiments of the present application, which is described in more detail and in more detail, but should not be construed as limiting the scope of the present patent. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present patent should be subject to the appended claims.

Claims

1. A precast lightweight aggregate concrete elevator shaft, characterized in that, It includes a basic module, a standard section module, a connecting corridor module, and a top-level module; The basic module includes a reinforced concrete base slab and a shaft sidewall extending from the bottom of the foundation to the ground level of the first floor; at the top of the four corners of the shaft sidewall, snap-fit ​​connecting sleeves that are reliably connected to the internal longitudinal steel bars are pre-embedded for docking with the standard section module above. The standard section module is a tetrahedral structure with doorways, including an enclosure wall system and a load-bearing structure. The load-bearing structure consists of irregularly shaped columns at the four corners, floor beams, inter-floor structural beams, and corbels. The lower end of each irregularly shaped column has a pre-embedded snap-fit ​​connecting rod, and the upper end has a pre-embedded snap-fit ​​connecting sleeve. Upper and lower modules are connected by snap-fit ​​insertion and sealed with structural adhesive. The corbels have pre-embedded snap-fit ​​connecting sleeves for installing the connecting corridor modules. The enclosure wall system uses a sandwich lightweight aggregate reinforced concrete wall. The standard section module is prefabricated in the factory, and its exterior decorative layer is consistent with the building facade. The exterior decorative layer uses one of the following: paint, brick cladding, pebble-dash plaster, or real stone paint, and is integrated with the lightweight aggregate concrete wall in the factory. The connecting corridor module includes a balustrade, a connecting corridor floor slab, and a floor drain; the balustrade also serves as a structural beam and handrail; one end of the connecting corridor floor slab is equipped with a snap-fit ​​connecting rod for sleeve-to-sleeve connection on the corbel of the same standard section module, and the joint is sealed with structural adhesive; the other end is used for connection with the original building structure. The top-level module integrates irregular columns, structural beams, enclosure wall system, top slab, and pre-embedded hooks; the lower end of the irregular column is equipped with a snap-fit ​​connecting rod, which connects with the lower standard section module, and the contact surface is sealed with structural adhesive; the thickness of the top slab is determined by calculation and is not less than 200mm, and the hooks are pre-embedded according to elevator parameters.

2. The precast lightweight aggregate concrete elevator shaft as described in claim 1, characterized in that, The total thickness of the sandwich lightweight aggregate reinforced concrete wall is 180mm or 200mm; a 60mm thick polystyrene board is embedded in the middle, and the two sides are 60mm or 80mm thick lightweight aggregate concrete layers; horizontal and vertical reinforcing bars are arranged inside the wall, with the horizontal reinforcing bars anchored into the irregularly shaped columns; the strength grade of the lightweight aggregate concrete is not lower than LC25, and the unit weight does not exceed 16kN / m³. 3 It is made from lightweight coarse aggregate, ordinary sand, cementing materials, additives and water.

3. The precast lightweight aggregate concrete elevator shaft as described in claim 1, characterized in that, L-shaped steel plates are fixed to the original building using post-installed embedded parts. The connecting corridor floor slab overlaps the steel plate with an overlap length of not less than 150mm, and the joints are sealed with structural adhesive. When post-installed embedded parts cannot be installed in the original building, structural columns are installed in the connecting corridor module. The upper and lower ends of the structural column are respectively equipped with snap-fit ​​connecting sleeves and connecting rods. The upper and lower connecting corridor modules are connected by snap-fit, and a connecting corridor foundation module is set at the bottom to provide support.

4. The precast lightweight aggregate concrete elevator shaft as described in claim 1, characterized in that, The construction method includes the following steps: S101. Site preparation and foundation design: First, the construction site is leveled and the foundation pit is excavated according to the design requirements; the foundation pit support design and foundation type selection are carried out in combination with the site geological survey data. S102. Cast-in-place construction of basic modules: Tie the reinforced concrete base slab and the side wall reinforcement of the shaft, and pour concrete after setting up the formwork; accurately pre-embed the snap-fit ​​connecting sleeves that are reliably connected to the internal longitudinal reinforcement at the top of the four corners of the shaft side wall to ensure their positional accuracy to meet the docking requirements of the upper module. S103. Standard Section Module Lifting and Connection: Apply structural adhesive evenly to the snap-fit ​​connection sleeve interface at the top of the shaft sidewall of the foundation module; align the snap-fit ​​connecting rod at the bottom of the prefabricated standard section module with the snap-fit ​​connection sleeve position, use lifting equipment to lift it to the predetermined installation height, and slowly lower it so that the snap-fit ​​connecting rod is inserted into the reserved snap-fit ​​connection sleeve to complete the fixation with the foundation module; S104. Installation of connecting corridor modules: If the original building structure allows, install post-embedded parts on the structural beams of the corresponding floors of the original building to reliably fix and extend the L-shaped steel plate; hoist the connecting corridor module to the installation position, align and insert the reserved buckle connecting rod at one end with the buckle connecting sleeve on the standard section module bracket, and overlap the other end on the L-shaped steel plate. Seal the gaps at the contact surfaces with structural adhesive to complete the fixation; if the original building cannot install post-embedded parts, use a connecting corridor module with structural columns: apply structural adhesive to the upper end of the structural column, align and insert the reserved buckle connecting rod at the bottom of the upper structural column with the reserved connecting sleeve of the lower connecting corridor module, and fix the upper and lower connecting corridor modules through buckle connection; S105. Layered Cyclic Installation: Apply structural adhesive evenly to the top of the installed standard section module, continue to hoist and fix the standard section module of the next layer according to the method described in step S103, and simultaneously complete the installation of the connecting corridor module of the corresponding floor according to step S104 until the design height is reached. S106. Top-level module installation: After the last standard section module is installed, apply structural adhesive evenly to its top; align the buckle connecting rod at the bottom of the top-level module with the reserved connecting sleeve of the lower standard section module, hoist it to the installation position and insert the sleeve, and fix it by buckle connection and sealing with structural adhesive. At this point, the main structure of the elevator shaft is installed.

5. The precast lightweight aggregate concrete elevator shaft as described in claims 1 to 4, characterized in that, Based on the site's geological conditions and flatness, if conditions permit, the foundation modules and connecting corridor foundation modules are preferably prefabricated in the factory: during prefabrication, the thickness of the bottom steel reinforcement protective layer is set to 70mm. After prefabrication, the modules are transported to the site for direct hoisting and installation, eliminating the need for additional cast-in-place subbase, thereby improving construction efficiency.

6. A method for controlling foundation settlement of precast lightweight aggregate concrete elevator shafts, characterized in that, The method applied to the precast lightweight aggregate concrete elevator shaft as described in claims 1 to 5 includes the following steps: S201. Acquisition of calculation parameters: Collect wind load parameters, foundation soil parameters, and shaft structure parameters of the residential area; the wind load parameters include the annual equivalent wind vibration cycle number N. y The azimuth angle θ of the prevailing wind direction, the wind load amplitude W0 along the shaft height, and the wind pressure height variation coefficient β at height z. z (z), wind vibration coefficient β s Wind load time history curves along shaft height; annual equivalent wind vibration cycles N obtained from meteorological data statistics. y It needs to be adjusted based on the regional wind environment, i.e., N y =N y0 ·K wind Among them, the annual equivalent wind vibration cycle number N of a typical old residential area y ∈[150,300] times / year, K wind The regional correction factor is determined based on the "China Building Climate Zoning Map"; the wind load time history curve along the shaft height is calculated using the community CFD wind field model, requiring input of the actual terrain roughness coefficient, inlet wind speed, and outlet free flow parameters; the foundation soil parameters include the compression modulus E. i The soil cyclic deformation parameters are m1, m2, and m3; the shaft structure parameters include the total height H of the elevator shaft, the planar length B1 and width B2, and the foundation bottom area A. g The fundamental frequency of the structure is f1, the mass of the prefabricated module is M, and the shear stiffness of the snap-fit ​​connection is K. c And the tensile stiffness K of structural adhesive s ; S202, Calculation of wind-induced cyclic stress: The formula for calculating the standard value of pulsating wind pressure along the shaft height is W. k (z)=β z (z)·β s • W0; Base wind-induced overturning moment M wind Satisfy the following expression: Base horizontal shear force V wind Satisfy the following expression: Base horizontal shear force V wind This leads to the generation of horizontal cyclic shear stress τ in the base. cyc It satisfies the following expression: Where, β t Let β be the horizontal stress concentration factor. t =1.2; The additional wind-induced base pressure q at the j-th corner point j Satisfy the following expression: Where, d j I is the distance from the j-th corner point to the basic centroid; g The basic moment of inertia; η j Let be the wind pressure weighting coefficient at the j-th corner point, and satisfy the following expression: in, Let θ be the azimuth of the j-th corner point; θ is the azimuth of the prevailing wind direction. S203. Calculation of uneven settlement of foundation: When uneven settlement of the foundation is mainly controlled by wind-induced additional pressure on the foundation base, the cyclic cumulative settlement ε of the i-th foundation soil layer at the j-th corner point is... ij Satisfy the following expression: Among them, m1, m2, and m3 are soil cyclic deformation parameters, calibrated through dynamic triaxial tests; σ v For effective overburden pressure; N cycle This represents the number of cyclic loads. The cumulative wind-induced settlement at the j-th corner point is S. j Satisfy the following expression: Among them, h i Let be the thickness of the i-th foundation soil layer; The uneven settlement ΔS satisfies the following expression: ΔS=max(S j )-min(S j ) Where max(S) j ) and min(S j The cumulative wind-induced sedimentation S represents the total sedimentation volume. j The maximum and minimum values; S204. Control of uneven settlement: The allowable value for uneven settlement [ΔS] is determined as follows: The allowable value for uneven settlement [ΔS] should not exceed the clearance between the snap-fit ​​rod and the connecting sleeve by 2mm; δ g Let δ be the allowable deviation value for the verticality of the elevator guide rail. g It is 1.5mm; When ΔS < [ΔS], the predicted uneven settlement of the foundation meets the requirements, and the foundation design scheme is feasible; when ΔS ≥ [ΔS], the predicted settlement does not meet the requirements, and reinforcement measures are required; the preferred reinforcement measure is to increase the foundation bottom area A. g Then, repeat the calculation process from steps S201 to S204 until the requirement of ΔS < [ΔS] is met.

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