超浅层顶管工作井建井技术

在顶管施工中，千斤顶的支座需要巨大的反力支持，这些反力是由工作井的侧壁以及壁后土体提供的。对于超浅层顶管工作井，由于侧壁后土体高差小，提供的反力有限，这就成为超浅层顶管工作井设计施工的一个难点。以实际工程为例，详细介绍了超浅层顶管工作井施工工艺，其中包括预注浆加固、环梁施工方法以及逆作法的施工要点等。

Construction Techniques of Working Shaft for Ultra-shallow-underground-pipe Jacking

In construction of pipe jacking, the wall of working shaft and soil body behind the sidewall offers enormous supporting force to a lift. But for ultra-shallow-underground-pipe jacking, the limited discrepancy between ground level and the bottom level of the shaft produces the difficulty for the designing and construction. The paper detailed construction technology of working shaft for pipe jacking in ultra-shallow shaft with a practical engineering, including some key points of pre-grouting, ring beam construction and top-down construction methods.