Sichuan, known as the province of a thousand rivers, is renowned nationwide for its majestic mountains and rivers and abundant water resources. In recent years, Sichuan has achieved remarkable accomplishments in the field of water conservancy project construction and is hailed as a major water conservancy province.

Data show that Sichuan completed 36.5 billion yuan of water conservancy investment in 2021, and exceeded 60 billion yuan in 2023. In just two years, the investment amount nearly doubled. Behind the boom in water conservancy project construction is the continuous advancement of Sichuan's modern water network development.

Recently, we visited the Tingzikou Reservoir and the Tuxikou Reservoir to observe the progress of water conservancy project construction.

Tingzikou Irrigation District: Annual investment target exceeded

On December 26, 2023, the reporter came to the Laowuba Aqueduct of Phase I of the Tingzikou Irrigation District Project, where a huge orange aqueduct-casting machine caught the reporter's attention. Just a few days earlier, the **span pouring operation of this aqueduct had just been completed here.

"This is the largest-flow aqueduct currently under construction in the entire Phase I of the Tingzikou Irrigation District Project. The aqueduct has a total length of 1.05 kilometers and 24 spans, with a maximum elevated height of 51 meters and a design flow of 51.5 cubic meters per second," said Jia Baojun, technical director of the EPC general contracting construction for Section II of Phase I of the Tingzikou Irrigation District Project under the construction contractor China Railway 18th Bureau Group, who spends almost every day at the site supervising project progress and ensuring construction safety.

"This area is mostly mudstone and sandstone geology, and the construction conditions for each pile foundation are different." Speaking of the difficulties in building the aqueduct, Jia Baojun pointed to the aqueduct-casting machine and explained, "Take this aqueduct: if calculated at maximum flow, the load weight will reach 2,400 tons. If the foundation is unstable, it will be very dangerous during later operation. Considering factors such as the complex geological conditions, the construction depth of our pile foundations must be precisely surveyed and calculated."

To this end, the construction contractor conducted scientific surveys of the surrounding geological conditions and determined that the construction depth of each pile foundation ranges from more than ten meters to several dozen meters, with the maximum pile foundation depth reaching 32 meters.

The rebar processing plant, a 10-minute drive from the Laowuba Aqueduct, is making every effort to ensure rebar supply.

Not only the Laowuba Aqueduct: the entire Section II of Phase I of the Tingzikou Irrigation District Project totals 71 kilometers. Because the terrain it crosses is mostly hilly, this section has 37 tunnels totaling 57 kilometers and 3 kilometers of aqueducts, with the aqueduct-to-tunnel ratio (the proportion of aqueduct and tunnel length in the entire section) approaching 85%, making construction extremely difficult.

It is understood that to ensure progress, the owner of Phase I of the Tingzikou Irrigation District Project has established four on-site construction management departments and, together with all participating parties, adopted a "daily huddle, weekly scheduling, monthly summary" system, "nailing" themselves to the site and solving problems on the front line to fully ensure the progress and quality of project construction.

As of now, the four sections of Phase I of the Tingzikou Irrigation District Project have cumulatively opened 269 work faces, holed through more than 60 tunnels, and completed an annual cumulative investment of more than 3,284.42 million yuan, with a completion rate of 109.5%.

Tuxikou Reservoir construction enters peak period: dam expected to be poured to 480-meter elevation before Spring Festival

Early in the morning on December 27, 2023, on the dam of the Tuxikou Reservoir, more than a dozen workers were laying a pink material on the dam crest, planning to cover every part of the dam crest.

"This is a 'thermal insulation blanket' made of PE (polyethylene) material, intended to allow the poured concrete to set better and develop greater strength, ensuring project construction quality," said a relevant person in charge from the construction contractor China Gezhouba Group.

The Tuxikou Reservoir is a Class II large (Type 2) reservoir within the Bashan Grand Canyon. The dam will ultimately be 132 meters high, making it the ** roller-compacted concrete double-curvature arch dam with a dam height exceeding 100 meters implemented in Sichuan's water conservancy sector, and also the ** large reservoir project implemented in Dazhou City.

The relevant person in charge stated that due to its special roller-compacted concrete process, it is "very delicate" during construction. Because summer and winter involve extreme temperatures, there is a great need to regulate the internal temperature of the concrete, temperature control requirements are extremely high, and construction is difficult.

In addition to temperature requirements, the Tuxikou Reservoir is also located in a canyon area with many unfavorable geological conditions, making construction difficult. It is also located in the Daba Mountain Geopark, adjacent to Dukou Township, and overlaps with the construction of the Bashan Grand Canyon scenic area and the Xi'an-Chongqing High-Speed Railway, involving many constraining factors, high safety risks, and heavy coordination tasks.

In August 2022, in light of the actual progress of the Tuxikou Reservoir project, all participating parties held in-depth discussions, worked backward from schedule milestones, and completed the compilation of an adjusted overall progress plan for the follow-up project, with completion planned for the end of December 2025.

"Now, the Tuxikou Reservoir has been poured to 37 meters, reaching an elevation (altitude) of 470.3 meters, nearly 3 meters above this year's target," the relevant person in charge introduced. At present, the Tuxikou Reservoir is in the peak construction period, and the construction "progress bar" has been pushed to the maximum. It is expected that the pouring can reach the 480-meter elevation before the Spring Festival!

As of now, the Tuxikou Reservoir has cumulatively completed an investment of 3.58 billion yuan. Among this, 500 million yuan was completed in 2023, and the annual plan has been fully completed.