女人毛片免费观看,女人脱了奶罩露出奶头,女上男下啪啪激烈高潮无遮盖,蜜臀av,懂色av,蜜臀av无码精品人妻色欲

Location:Home?>?detail
Location: Home?>?News Update?>?News Update
China’s First 7-Meter Ultra-Large Diameter Raise Boring Machine Goes Into Operation
Source: Date:2025年06月16日

On May 26, China’s first domestically developed 7-meter-class ultra-large diameter raise boring machine, “CREC?No. 1361,” developed by China Railway Engineering Equipment Group under China Railway Hi-Tech Industry, was officially commissioned at the Jingning Pumped Storage Power Station in Zhejiang. It will be used for constructing the plant’s vertical ventilation shaft.

The ventilation shaft at the Jingning Pumped Storage Power Station is 7 meters in diameter and 319.73 meters deep. It is being constructed using a single-pass raise boring method with a large-diameter machine. The “CREC No. 1361” raise boring machine has a maximum designed excavation diameter of up to 8 meters, offering advantages such as high stability, safety, and environmental protection.

Compared to traditional shaft construction methods involving drilling, blasting, and reaming, the single-pass raise boring technique eliminates the need for blasting, reducing noise and vibration impacts on the surrounding environment. It also reduces the number of personnel required, effectively lowers construction safety risks, and enhances shaft construction efficiency.

Print Close