aa级一级天堂片免费观看_国产中文免费精品无码视频2_国精品午夜福利视频性色_亚洲无码无需下载_大菠萝福建网站引导入口404

In recent years, with the rapid development of the domestic economy, large and medium-sized urban urban redevelopment projects, the transformation of the old city, subway tunnels, underground envelope structure, bridge expansion project and other projects continue to encounter underground rocks and residues Of the old concrete structure, the old pile foundation and other obstacles need to be removed, these underground obstacles have become a thorny problem of underground construction. With the frequent development of the existing underground pile foundation in the design and construction process, the original pile foundation can not meet the upper load, the construction site of the small underground continuous wall into the trough on the brink of high-rise buildings and other issues. Often resulting in redirects or redesign part of the construction halfway, a direct impact on the construction progress and quality of the project, so clear the work of underground obstacles is very important. In view of the current situation and demand of urban development, the developed countries have developed a full-swing casing drilling, such as China in 2004 from Japan to introduce a 360 ° full rotary casing drilling rig. The equipment can not destroy the surrounding soil in the case: the underground waste steel concrete structure removed, the pile foundation without removal or replacement, but also for drilling bite the bite of the hard bite of the enclosure construction. The emergence of this method - to achieve the civil technical staff in a conglomerate formation, all kinds of pile foundation, reinforced concrete structure and other obstacles without the removal of the local implementation of the filling pile, replacement pile, underground continuous wall and pipe jacking, Shield tunneling is accessible through all types of pile foundation. Full rotary equipment is widely used in Shanghai and the surrounding areas of rail transit, large-scale cross-river tunnel construction of underground deep obstacles and various types of occlusal pile foundation. Engineering practice shows that the use of all-rotating equipment clearance piling with fast, safe, efficient, environmental protection, etc., because of its own diesel power plant, the use of more convenient.