Bolstered by enhanced investment in the infrastructure sector this year, accelerated progress was seen in many projects nationwide recently, which experts said will not only shore up the nation's economic momentum in the short-term but is also expected to play a critical role in lifting livelihoods in the long run, reflecting the results of the nation pushing the effectiveness of investments in many key meetings this year.

China Railway 24th Bureau Group Corp Ltd (CR24), a unit of State-owned enterprise China Railway Construction Corp, said its team working on the Longyan-Longchuan High-speed Railway project has completed the "toughest" construction phase of the project, with the Jinyuding tunneling successfully completed on Friday.

Located in Shanghang county in Longyan, Fujian province, with a length of 4.43 kilometers, the Jinyuding tunnel is labeled as a construction area with the most complex geological conditions and the worst construction environment, requiring the most diversified tunneling solutions among all the sections of the entire railway.

"There are many fault areas along the tunneling route which, if not handled carefully, may lead to mud and water inrushes, as the tunnel is located in an area rich in underground water," said Yu Shangjun, project manager with CR24.

"In addition, the tunnel will go through four near-surface rock layers — with its top only 8 meters to 12 meters below the surface ground — where the surrounding rock is fragile, leaving us tons of work in handling stability. There are also creeks running on the surface," Yu said, adding that with the high-speed rail being laid through the Shanghang National Forest Park, it's a basic rule for the whole project team to finish the whole construction job in an eco-friendly manner.

Teams were formed by CR24 to cope with each variation of issues standing in the way. "We first established teams to run geological reports and monitor each period prior to construction and then drafted a tunneling plan in accordance with the conditions we faced. Then, supported by high-accuracy scanning equipment, the teams started tunneling, step-by-step, and managed to finish digging the Jinyuding tunnel," the manager said.

As a rail linking Fujian and Guangdong provinces, the Longyan-Longchuan High-speed Railway has a planned length of 265 km and a designated speed of more than 250 kilometers per hour, which will play a key role in strengthening the connectivity of the coastal regions.

In inland areas, major progress was reported on the second highway linking Chongqing and Hunan province.

The CRCC unit said its tunneling work at Zhongbao county for the second Chongqing-Hunan highway, of which 80 percent of projects are tunneling work, is nearing completion after its construction team overcame major difficulties including tunneling through water-soluble rock layers, stabilizing the tunnel under rich-in-water areas and prevention work against water and mud inrushes. The tunneling is expected to be complete later this month, laying a solid foundation for opening the highway ahead of schedule.

The CR24 project manager, who declined to be named in this article, attributed the successes that have been made so far to countless simulation exercises before each process and adequate preparation work.

Comprised of three major sections, the second Chongqing-Hunan highway has a total length of 280 km, and is planned to address the long-suffering highway congestion issue between the two provincial-level regions and facilitate travel to cities along the route, which boast many tourist attractions.

The nation has seen an uptrend in launching infrastructure projects this year. Fu Linghui, spokesman for the National Bureau of Statistics, said during a news conference recently that newly launched infrastructure projects reached 52,000 in the first eight months of the year, and highlighted "the key role of investment in stabilizing the economy and sustaining recovery".

The NBS said fixed-asset investment increased by 5.8 percent year-on-year in the January-August period, compared with a 5.7 percent rise in the first seven months. Notably, infrastructure soared 8.3 percent over the January-July period, reflecting the government's efforts to stabilize growth.

Apart from realizing the significance of investment in bringing up the employment rate and disposable incomes which, as a result, will boost consumption, the government should focus more on the effectiveness of investment and make plans in advance to have the investment take effect as soon as possible, said Jia Kang, chief economist of the China Academy of New Supply-Side Economics, during this year's China International Fair for Investment and Trade.

He Jingwei and Zhang Ying contributed to this story.