The lightweight concrete filling is getting closer to the top of the bridge.

■ The backfill of lightweight concrete is already more than 2.5 meters thick.

■ Construction personnel inspect the inner wall of the drainage pipe.

■ Construction workers are installing the drain pipe.

Citizens walk on temporary non-motorized lanes.

Today, the backfilling project of

Zhongshan Road underpass bridge has been affecting the hearts of people in the provincial capital. On the morning of August 17, the reporter came to the construction site to find out. The builders

who

participated in the backfilling project of the underpass bridge on Zhongshan Road were interviewed

. "Every day when I pass here, I can't help but look inside the enclosure to see how far it has progressed."? I also want to see what it will look like in the future. On the morning of August 17, standing on the south side of the underpass bridge of Zhongshan Road under construction, watching more and more light concrete backfill under the underpass bridge, 71-year-old Chen Mingfa's mood, like many provincial capital citizens, is very complex, reluctant and more hopeful.

Reporters noted that at this time, the four holes of Zhongshan Road underpass bridge can still be seen, but the light concrete filled under the bridge is getting closer and closer to the top of the bridge. The northernmost bridge hole and the second bridge hole on the south side are laid with very thick black pipes. According to the on-site construction personnel, this is a drainage pipe.

"What exactly is the lightweight concrete backfilled here?"? Why backfill this material? Zhao Qing, an expert from China Railway Design Group Co., Ltd., said that under the backfilling scope of Zhongshan Road, the Beijing-Guangzhou high-speed rail Tunnel is in operation. Due to the high requirement of high-speed rail for track smoothness, the backfilling needs to reduce the density of filling materials as much as possible, reduce the load above the tunnel, and avoid the impact of local settlement on the operation safety of high-speed rail. Through research, demonstration and comprehensive comparison and selection, the design scheme adopts polystyrene particle concrete lightweight filler, the density of the filler is about 30% of the ordinary earthwork, and the strength and stiffness meet the requirements of the upper road operation.

So how does this lightweight concrete get backfilled under the bridge? It turned out that several builders were holding long pump pipes, aiming at the ground under the bridge, and the light concrete was sprayed out of the pump pipes. The concrete pump truck connected to the pump pipe is parked in the closed construction shed. The ground under the bridge rises little by little as the lightweight concrete keeps pouring out of the pump pipe. Sun Guopeng, the project manager of China Railway Electrification Bureau in charge of the construction of the project, said that since the start of the project on August 1, the main road of Zhongshan Road has completed the work of breaking the original pavement and backfilling 30 cm graded gravel, and is making every effort to lay municipal pipelines and backfill light concrete.

In the reluctance and longing of the citizens, the backfilling project of the underpass bridge on Zhongshan Road is moving forward with all its strength. It will soon be completely filled up and become a level crossing with Shengli Street, and begin to fulfill a new traffic mission.