备受关注的中国西气东输工程又有阶段性的重大进展 ,其“咽喉”部位的郑州黄河顶管穿越工程首段已于 5月 2 3日正式贯通。据介绍 ,郑州黄河顶管穿越工程长 3 60 0m ,设 4个沉井 ,分 3段顶进。工程位于地质条件极为复杂的黄河古老河床下 2 3m深处 ,在面临摩擦力大、水压大、中心 The much-anticipated progress of China’s West-East natural gas pipeline project made major milestones. The first phase of Zhengzhou Yellow River Pipe Jacking Project on the “throat” site was formally closed on May 23rd. According to reports, Zhengzhou Yellow Pipe jacking through the project length 3 60 0m, set up four caisson, sub-3-stage advance. The project is located in the deep geological conditions of the ancient river bed 23 meters deep, in the face of friction, water pressure, the center