Market status analysis of the current construction market: 1.
Construction communication media ID: jianzhong001 Changsha project is ill fated.
The construction quality is poor, the fault tolerance rate is low, and the design limit is reduced.
The construction quality is uneven, which is closely related to the management level and quality of the general contractor and labor personnel.
In the roof backfilling stage, there are no reinforcement measures.
The illegal operation of the earthwork unit and the negligence of the supervision of the third-party supervision unit are the main reasons for this event.
The secondary reason is that the three columns themselves have process defects, resulting in varying degrees of damage! Case 2 Basement collapse According to the information released by Zhongjun yongjingwan, the period of this accident is also the period of roof backfilling.
Under the cold winter, the basement collapse of relevant units involved is not disclosed.
Most of the structural types are beamless floors.
In the early morning of November 27, during outdoor garden construction, part of the earth covered roof of the basement collapsed; After the collapse, the construction unit issued an emergency notice, trying to clarify that the garage collapse would not affect the structural safety of the main building.
Official reasons: insufficient design safety reserve, insufficient consideration of adverse working conditions of construction load, and weak measures to prevent continuous collapse; The second important reason is that the construction unit is overloaded in the earth covering construction, resulting in punching failure at the junction of supporting plate and roof, which is the direct cause of basement roof collapse.
The other general contractor, China Construction x Bureau, negotiated with the builder for material difference adjustment for many times, and more than 12 million cables alone have to be compensated.
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Or the backfill load of the garage roof exceeds the standard, resulting in the deflection and deformation of the roof, cracks and even collapse.
The design unit dare not offend “Party A’s father” and play a marginal ball under various pressures.
For example, I don’t think it should be the designer’s idea to cancel the concealed beam in the beamless floor.
What is the reason? The following is worth learning from.
The notice said that it was reported to the relevant government regulatory authorities at the first time, and then the housing and urban rural development department appointed structural experts from Hunan University to conduct a field survey of the incident project; Experts preliminarily determined that the reason was that the concentrated soil stacking of the garden team was too high, and the construction team used large-scale excavation equipment to enter the structural roof for barbaric operation, resulting in collapse; According to public information, Changsha tongx Construction Co., Ltd.
This article is only for technical discussion.
It can be seen from the accident pictures on site that in the earthwork backfilling stage, Zhongjun yongjingwan basement has not been reinforced with underground roof! No reinforcement trace is seen inside the collapse case 3 Basement collapse of Zhongshan Vanke project On November 12, 2018, the basement of Zhongshan Vanke project collapsed, which had a great impact! Among them, the collapse area of basement roof is about 2000 square meters, and the collapse area of basement floor is about 1500 square meters.
is responsible for the construction of 18 #-20# high-rise residential buildings, 14 #-17# high-rise residential buildings and basement in West District, 21 #-22# high-rise residential buildings and 23 # kindergartens (filed for bankruptcy) constructed by Hunan yuanx Construction Co., Ltd.
Today, let’s take a look at these cases.
The earth rock construction unit gathered the soil in one place without authorization and ran a heavy tonnage tractor on the garage roof, which led to the collapse of the garage roof.
Basement roof collapse and structural damage accidents occur frequently.
of China Construction x Bureau.
If your project is in the stage of centralized stacking, garage roof backfilling, or the underground garage under construction is a beamless floor, be sure to read this article carefully! Case 1 Structural column burst on November 20, 2019, the top concrete of several structural columns of an underground garage of a building in Guangxi burst, and the reinforcement was bent and exposed! Some buildings of this real estate were delivered to the owner without acceptance, which is a serious violation! The person in charge of the community responded: the main reason for the structural column burst is that the local stress is too large due to the earth stacking load exceeding the design limit during the backfill of the community.
Earthwork units are generally designated by Party A, and most of them are local “bosses”, which is difficult to manage..
Real estate developers generally have the lowest steel content, and the safety factor is relatively low.
The accidents occur in the backfill stage of the roof, and the local surcharge is too high.
The differences between Party A and Party B led to slow construction progress; Seeing that the building was to be delivered overdue, after the owner complained, the government departments coordinated and resumed work, and the construction party urgently organized rush work.
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No reinforcement trace is seen inside the collapse case 4 Heyuan basement collapse at 3:35 p.m.
There is no reinforcement trace inside the collapse.
If your project is under outdoor construction, please forward this article to remind you.
An article specially edited by the Civil Engineering Forum reminded that more than 90% of the basement collapse occurs in the garden construction stage.
After reading these cases carefully, they basically have one thing in common: 1.
According to the official investigation: the roof backfill construction is under way in the basement collapse stage! Case 5 Collapse of Jinan mingliuhuadi basement on November 17, 2014, the report of local collapse accident of garage roof of mingliuhuadi building under construction in Changqing District, Jinan was released.
on December 5, 2014, the basement roof of Heyuan Yajule Garden Phase II area 4 project collapsed locally, with a collapse area of about 480 square meters.
The 1#-13# high-rise residential building and the basement in the east area constructed by the first Construction Engineering Co., Ltd.
In the past two years, the epidemic situation superimposed on the sharp rise of building materials, one of the general contractors went bankrupt, and the bid section was completely shut down.
The reasons are mostly limited construction site, premature or excessive stacking of building materials on basement roof, and even driving heavy machinery and equipment.
For why the local collapse of garage roof occurred, the appraisal center gave the following appraisal conclusions: according to on-site inspection and detection, checking calculation of garage roof bearing capacity Calculation and comprehensive analysis of the bearing capacity of the garage roof under the condition of 7.0m thick soil stacking, the collapse of the garage roof is caused by the soil stacking load exceeding the design service load.
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The accident is definitely not accidental.
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