Tower cranes are the most common lifting machinery at construction sites. Tower crane provides great convenience for high-rise building construction, at the same time, the safety of tower cranes should also be highly valued by engineers as there were countless tower crane accidents occurred.
On February 24th, 2019, the tower crane which was working on the Masland Hotel Project in Gongxian County, Sichuan Province collapsed, caused 3 construction workers to fall to death at high altitude.
On the afternoon of February 26th, 2019, a tower crane collapse occurred at a construction site in Tongguan District, Tongling City, Anhui Province. When the tower crane was used to lift the steel bars, the wire rope broke caused the tower crane body to swing too large and collapsed, causing 2 deaths, 1 serious injury and 1 minor injury. The seriously injured people was sent to the hospital but died after salvage attempt failed. Along with the rapid development of construction industry in recent years, the tower crane collapse accident happens occasionally. The large and small accidents not only delay the process of the construction project, but also seriously threaten the safety of life and property.
As a common construction machine, tower cranes can realize the vertical and horizontal transportation of materials. As tower crane structures are large yet heavy and performing high-altitude operations, so the collapse accidents are prone to occur. The safe operation of the tower crane not only requires the tower crane driver to have professional skills and psychological literacy of aerial work, but also needs to monitor the running attitude in real time, so as to prevent the tower crane accident.
The safety devices installed on the tower crane include a weight limiter, a lifting torque limiter, an amplitude limiter, a lifting height limiter, a swing limiter and etc. The function of these safety devices is mainly that once the tower crane exceeds the safety value in the process of use, the power supply will be automatically cut off to avoid tower crane accidents. However, there are some hidden dangers on tower cranes that the safety devices cannot be detected. For example, the tower crane is prone to tilt when it's processing the inclined pull and its foundation pile settles unevenly. Many factors such as excessive back rake angle caused by sudden unload of heavy object and unfirm bundling of heavy objects and etc. will lead to tower crane tipping accidents. The use of tilt sensor will monitor such potential safety hazards in real time to prevent accidents before occurrence.
By effective inclination monitoring of tower crane body during working process, timely alarm can effectively prevent the tower crane from tipping over when the inclination angle is greater than a certain critical state. Therefore, the building construction unit generally installs the inclination sensor in the front and rear sections of the tower crane for detecting the inclination angle of the balance arm in real time, so that the engineering operation can be safely secured.
In the above figure, Vigor Technology SST810 dynamic inclinometers are installed on the 1, 2, 3 point for measuring the real-time dynamic attitude of the boom and calculating the real-time flexible deformation state of the boom. SST400 static inclinometers are installed on the 4 and 5 point for monitoring the static attitude of the tower crane. Based on the static model, the real-time spatial attitude of the tower crane body and the boom in the ground coordinate system can be obtained through the SST400 inclination sensor. This tower crane monitoring solution meets the real-time alarm requirements of the system and the data analysis needs of various construction processes.
Since the tower crane is mainly working in the outside, not only the high temperature and low temperature have an impact on it, but also the heavy rain and windy weather has an impact on the tower crane. The static and dynamic tilt sensor are closely matched to measure the tilt angle of the tower crane in real time. Since the inclination of the tower body top changes little, the sampling frequency of the inclination measuring device should be in the range of 0.5-10Hz, the measuring accuracy is high. At the same time, it is necessary to filter out the noise caused by the vibration at the top of tower and ensure the reliability and accuracy of communication.
Vigor Technology is one of the industry-leading enterprises in China for posture, position and orientation measurement. We provide complete tower crane safety monitoring solutions and ensure the safety of the tower crane and the operating personnel.
Contact: Vigor Technology
Phone: +86 18017387742
Tel: +86 021-58404921
Add: Block H1, No. 161, Lane 3188, Xiupu Road, Pudong New District, Shanghai