Beijing City 6th District Inspection Wells Protection Net Prevents "Bite" Pedestrians

Don't let the man open his mouth to "bite" the pedestrian

City six district inspection wells installed protective net

Because of the theft, loss, and damage of the circular manhole cover, the “black hole on the road” has caused several injuries to passers-by. With the advent of the rainy season, the probability of occurrence of top support in rainwater inspection wells in low-lying areas of the road is also increasing. The person in charge of the Beijing Drainage Group said yesterday that as of the end of May, 10,787 inspection wells have been installed on the main roads and sidewalks in the main streets of the Chengliu District, covering 293 trenches. These protective nets under the covers can catch pedestrians accidentally sliding into the wellhead.

Safety net weight 150 kg

Yesterday afternoon, the reporter saw this downhole protective net on the sidewalk of Ping An Street. Drainage inspection well protection net consists of guard nets and expansion bolts and can hold 150 kilograms. The high-strength wire material used in the protective net has a diameter of 6 mm and looks similar to the thickness of the net hanging on the goal of a football game. In order to prevent pedestrians from inadvertently sliding into the wellhead and embedding their feet in the mesh, the side length of each square grid on the nursing net is 8 cm. The sneakers worn by adults on the 26th can step on 3 grids.

The guard net is suspended about 15 centimeters from the wellhead of the inspection well and is fixed to the wellbore wall by expansion bolts. It is worth mentioning that during the actual installation process, the number of expansion bolts used to fix the protection net increased from 6 in one circle to 8 in one circle. The technician also adjusted the bolt hook closure to 350 degrees.

"The bolts are almost completely surrounded by the guard net, leaving only a 10 degree gap, and the guard nets can be hung on the hooks one by one." The technician said that taking into account the moisture in the inspection wells and the corrosive gas, the expansion The bolts are made of stainless steel, which fully improves the safety factor of the protective net. This means that after a manhole cover is missing, if a passer-by accidentally slides in, it will not be seriously injured.

Does not hurt people high-strength wire thicker 2 mm

In order to develop this protective net, Drainage Group's technical staff specially visited the protective fabrics manufacturer located in Fangshan District to “acquire the scriptures”.

“Considering that people wear thin clothes in summer, high-strength fibers synthesized from chemical fiber materials have undergone repeated tests. We have ensured their strength and toughness, and at the same time, we have reduced the degree of injury to the limbs of the human body to a low level. Therefore, we have given up the use of hard The metal material is used to make the protection of the network.” The technicians said that in addition to the screening of materials, the thickness of the protective network cable is also very particular.

In the final implementation of the design, the high-strength wire used for each guard net was 6 mm in diameter. The original "4mm diameter" solution provided by the manufacturer, although the overall cost is slightly lower, but because the high-strength wire consists of a finer wire, it is easy to cut into the pedestrian's limbs, so after repeated tests, the drainage group finally selected a diameter of 6 Millimeters of guard nets.

Strictly check and try again after 1 year

Rainwater inspection well protection nets are used for the first time in this city. In order to convert the design parameters of the protection nets into actual results, technicians have also conducted a “dropping” experiment before installation.

I saw an iron ball weighing 150 kilograms, falling from the position 1.5 meters above the wellhead to the guard net. When the iron ball comes into contact with the protection net, the end is securely “protected in the arms” by the protection net. The concave mesh surface did not appear damaged, and the expansion bolts did not separate from the wellbore wall.

“The tens of thousands of inspection well protection nets already installed in Chengliu District are still in the probation period. The city's pipe network operating subsidiaries will conduct evaluations and observations on the protection nets for one year. Based on their use effects, it will determine whether the coming year is within the scope of the city. The company continued to promote it.” According to the person in charge of the Drainage Group's Pipeline Department, from the current point of view, due to the installation of protective nets in the inspection wells in the Sixth District, it is bound to increase the workload for patrolling personnel to go downhole. For this reason, when the drainage group asks the patrol personnel to check out the well, the protective net must be firmly tied up to ensure that it fully recovers its protective function.

Next:Installation, use and regulation of marine diesel generator sets
Previous post:The old man bought 250,000 yuan of health care products in 2 years and issued regular certificates to him