Although some threaded piles of the railway did not reach the design length, they were embedded in a good bearing layer, which did not compromise the quality and safety of the composite foundation, the investigation observed. It also noted that there were no quality issues or safety hazards with the composite foundation, and this did not affect the safe operation of the railway.

 

Tests show that the railway met requirements for track smoothness at a speed of 350 kilometers per hour and met the safety and stability requirements for high-speed train operation.

 

In July, media outlets reported that there were quality issues in the construction of the railway, including questions about threaded piles not reaching the design length, and the participating units did not follow design change procedures.

 

Following the reports, a joint investigation team consisting of professionals from the Shanghai Railway Supervision Administration and the Shandong Provincial Transportation Department was swiftly formed to investigate the issues. 

 

The investigation team organized more than 120 professionals from across the country and sought technical guidance from 10 experts in railway and geology.

 

The investigation found that when the pile length did not reach the design length, but the pile end entered the bearing layer. The constructors only held on-site meetings for confirmation, but failed to follow the specified procedures for design changes.

 

Sanjie Industrial Co, a subcontractor for drilling poles, and China Construction Eighth Engineering Division Corp, the main contractor, had conflicts concerning construction progress and engineering payment, according to the investigation. 

 

Sanjie withdrew from the construction in June 2021, and the two companies have not resolved the dispute. The investigation also revealed issues with on-site management and improper subcontracting in construction management.

 

Regarding issues related to design changes, construction management and engineering subcontracting, the Shanghai Railway Supervision Administration imposed administrative penalties on the relevant responsible units and seven individuals.

 

In addition, 10 individuals from companies participating in construction, supervision and design received disciplinary punishment, it said.