A worker works on the Xihuchong bridge of the Qiangjiang-Zhangjiajie-Changde railway under construction in Hongyanxi Township of Longshan County, central China's Hunan Province, Aug. 25, 2018. (Xinhua/Zeng Xianghui)

Photo taken on Aug. 25, 2018 shows the Xihuchong bridge of the Qiangjiang-Zhangjiajie-Changde railway under construction in Hongyanxi Township of Longshan County, central China's Hunan Province. (Xinhua/Zeng Xianghui)

Aerial photo taken on Aug. 25, 2018 shows the Xihuchong bridge of the Qiangjiang-Zhangjiajie-Changde railway under construction in Hongyanxi Township of Longshan County, central China's Hunan Province. (Xinhua/Zeng Xianghui)

Aerial photo taken on Aug. 25, 2018 shows the Xihuchong bridge of the Qiangjiang-Zhangjiajie-Changde railway under construction in Hongyanxi Township of Longshan County, central China's Hunan Province. (Xinhua/Zeng Xianghui)

Aerial photo taken on Aug. 25, 2018 shows the Xihuchong bridge of the Qiangjiang-Zhangjiajie-Changde railway under construction in Hongyanxi Township of Longshan County, central China's Hunan Province. (Xinhua/Zeng Xianghui)