【 Weak current College 】 high-rise construction elevator floor special installation scenarios

Introduction: this article describes the construction elevator Foundation cannot fall to the Foundation, which is to be installed in the basement have been used on the roof structure engineering, detailed the high-rise building construction, construction of the lift is installed in the basement floor structure, based on the special treatment programmes; and structure construction elevator Foundation beam design account book.

Keyword: construction elevator beam infrastructure transfer structure bearing stability settlement

Construction elevator as high-rise building materials and personnel must for vertical transport, construction machinery has been widely used, the elevator is an important component of construction elevators, which directly affect the safe operation of construction elevator. Therefore the elevator based design and construction is extremely important and should be according to the Foundation in conjunction with engineering characteristics to calculate. But here are introduced on the basis of construction elevator cannot fall to the Foundation, which is to be installed in the basement have been used on the roof structure engineering.

A, project profiles

Chongqing Club International gardens to work at Guanyinqiao, Jiangbei district, Chongqing, the Trade Center site, it is a "long", basement and podium portion as "modern Plaza" was officially approved in 1999. Club International famous works from the seven-layer dress up for continuation of A, B, c, high-rise buildings, construction area of 16.0 million square meters, of which: A seat 48 floors high 154.5 meters, construction area of 6.2 thousand square meters; engineering structures of shear wall structure for super high-rise building.

According to the Club International famous engineering A block, the actual situation at the scene, engineering week again no construction site, only in the axis of the lateral postal business, namely, the three-tier roof roof structure on a basement space can be used as construction sites, construction machinery and equipment installation. But this project is 48 layer of super high-rise building, construction elevator installation height requirements to achieve centralized computing 146m, load, as the sole installation of elevator postal business of the three-tier roof structure, unbearable and loads of transfer, and ruggedized substructure, and therefore cannot be installed in the floor structure of great difficulty.

Project engineer his brains, finally ventured to the construction of the lift is installed in the lane shear wall with two columns, using the "T"-shaped reinforced concrete flat beam structure, as the basis of special construction elevator installation scenarios.

Second, the basic design of construction elevator

1. construction elevator Foundation design difficulties:

A, construction elevator so load the parts of the roof beam and slab structure could not bear, is not possible to lift the Foundation directly on the roof;

B, the site of three-layer following is postal business warehouse is in use and cannot be on the bottom beam reinforcement;

C, construction elevator installation location of the lower reaches of the vertical structure of the span and the lift base 8000mm medial support cannot directly support vertical structure, it is necessary to make structural transformation;

D, construction elevator height is based on the restrictions of the slope.

2. construction elevator Foundation form and reinforcement design

Due to concentrated load construction elevator to 600KN, load is large, so the lift foundations Foundation beams for load transfer. Beam base reinforced concrete beams and steel beams in two forms, but consider medial Foundation beams bearing to make structural transformation, we are in the actual construction is in the form of reinforced concrete beams as construction elevator.

Construction elevator Foundation beam dimensions L1: 1000mm wide × high beam width 500mm is under construction elevator standard width 750mm determine, on high beam is considered the height of slopes.

Inner bearing structure transfer beam dimensions: L2 400mm w × 800mm high, L2 in axis bearing reinforced concrete Corbels.

Construction elevator Foundation beams L1, L2 and ox's leg reinforcement design.

3. basic plan construction elevator

4. construction elevator Foundation beam load transfer forms

A basic beam L1 load transfer:

B, Foundation beam L2 and ox's leg load transfer:

III. construction construction elevator Foundation beams

1. Mark storey 8.1M floor structure axis measurement to ensure basic primers beam bearing position accuracy. Axis leads by floor axis network, determine the location, the pop-up Foundation beam base beam template cords and control cables, and eject bottom shear wall side, check the location of shear walls.

2. construction elevator Foundation beams outside end bearing, chisel in addition to the floor screed, ensure construction elevator Foundation beams support in the lower portion of the vertical structure, bearing parts to increase the implantation of the lower wall bracket connection reinforced, construction protects the original structure of concrete; construction elevator Foundation beams inner end bearing through the L2 L2 beam, girder to attention concentrated load node of reinforced strengthened.

3, L1, L2 elevator Foundation beam laying 50mm isolation layer, the isolation level using sand, sand cushion week again brick surface cover cotton cloth, Elevator Foundation beams reach after clear, ensure that the strength of elevator Foundation beams and the lower part of the structure of the gap between 50mm, prevent the lift base beams load to the lower beam delivery.

4, floor beams base template, fastening and beam reinforced concrete beam, design templates, to blot and be buried and iron.

5. pour the concrete foundation beam C30, correction of anchor bolts, beam surface leveling.

6, concrete pouring the sand bedding must be removed, clean.

7. the basis for the assurance construction elevator, lateral stability of standard-report of the wall started to increase the long stage with wall should also be appropriately increased.

4. settlement

Construction elevator constructionProcess each loaded once, have to be a basis for settlement construction, now has to lift total height, after repeated 146m settlement construction elevator basis maximum settlement (which is the maximum deflection of beams) not exceeding 20 mm, meet design specifications, (beam design maximum permissible deflection [f] for the calculation, please refer to the attached page 40.2mm construction elevator Foundation beam design account book).

5. concluding remarks

This construction elevator construction in basic setup has finished floor structure, this is the first time we met, and the installation location for the Office, there is no other alternative location, we passed through the filter of the various programmes, that only the programme of economic utility. After a year of using all normal, not on the lower part is in use without affecting any of the structure, management, owners have been recognized and praised. Construction elevator in high-rise construction, already widely in use. The Foundation also has a variety of design options, these are the basic design of the floor structure of the construction plan for our future construction in the same situation is with reference to experience.

Sheet: construction elevator Foundation beam design account book

First, the Foundation beams L1 (1000 × 500)

1. design basis: a, SCD200/200 construction elevator statement;

B, concrete structural design standard GB50010-2002

C, the original structure construction drawing design

2, load calculations

Calculation of data

A design based on the original structure, construction drawings (detailed above) and construction elevators installed parts, basic design bearings to the original structure 300mm wide shear wall, calculate net cross-8040mm.

B, according to construction elevator usage and installation requirements, Foundation design width 1000mm, height 500mm.

C, construction elevator installation height 154.9-8.1 = 146.8M, Elevator loads:

Hoists (double cage) 2 × 20KN

Guide mechanism (146.8 ÷ 1.5 ≈ 98 Festival, 1.8KN/section) 176.4KN

The 2 × 10KN

Load 2 × 20KN

Total: 276.4KN

Dynamic load of the safety coefficient: K = 1.4

Design calculation load P = 276.4 × 1.4 = 387KN

Base weight: d, b = 1.0m, h = 0.5m, specific gravity 25Kn/m3, the safety coefficient K = 1.2

q==15KN/m

3, the moment of calculation (the concise structural design manual P56, 57)

Concentration: MC = 245867N · m

MB===449208N·m

Uniform force: MC = N · m

MB=N·m

Calculate the bending moment: MC = 245867 + 40401 = 286268N · m

MB=449208+80802=530010N·m

4, reinforcement (the concise structural design manual P167)

Beam cross section dimensions 1000 x 500 concrete C30

Upper reinforcement: A =

Checking table have (the concise structural design manual P168): ρ (%) = 0.926

AS=

Selected F 28, 10 root, AS = 6153 mm 2.

Bottom bar: A =

Lookup (the concise structural design manual P168) have: ρ (%) = 0.478

AS=

Actual distribution 10 root F 28, AS = 6153 mm 2.

5. calculation of deflection

Allowed deflection [f] = (the concise structural design manual P225)

ρ=

Short rigidity (the concise structural design manual P215) BS =, look-up table (P219) seek: (= 0)

BS=1544×1000×4503=1.41×1014

f=

F = 13.67 mm < [f] = 40.2 mm in compliance with the requirements

II. Foundation beams L2 (400 × 800) design

Load

Moment (the concise structural design manual P57)

1) q1 action:

Under action 2) q2: (concise structural design manual P57)

Calculate the bending moment: Mmax = 667430 + 9216 = 676646N · M

MB=341452+18432=359884N·M

Reinforcement (the concise structural design manual P167)

Beam cross section dimensions 400 × 800 concrete C30

By rail:

Lookup (the concise structural design manual P168) have: ρ (%) = 1.113

Selected F 25, 7 root, AS = 3436 mm 2

OnIron:

Lookup (the concise structural design manual P168) have: ρ (%) = 0.559

Selected F 25, 4 root, AS = 1963 mm 2