施工過程を考慮した浅層トンネル掘削技術の開発

开发地下空间对市区的发展及/或重建至关重要。由于环境因素和地表利用等因素的限制，城市常用盾构隧道、新土法等隧道法来代替开挖和覆盖法来开采地下空间。城市隧道通常建在较浅的地下深处，有时断面较大。在此类隧道的施工中，应重视地表沉降等地面运动和对既有建筑的破坏以及隧道的土压力。通过对城市浅埋隧道开挖过程中地表运动和土压力的研究，设计出合理、经济的城市浅埋隧道施工方法。为此，我们进行了弹塑性单元分析，更充分地考虑了土、结构和土与结构界面的力学行为，并进行了相应的模型试验。本研究的主要内容如下：●考虑地面为绿地，研究隧道开挖过程中土体覆盖对地表沉降和土压力的影响●研究既有上部结构（建筑荷载）对隧道开挖的影响。●验证既有上部结构不同荷载水平对浅埋隧道开挖引起的地面变形的响应。●研究大断面、两条或多条平行隧道开挖顺序对地表沉降和土压力的影响。描述隧道开挖对地表沉降和土压力的三维影响。●按顺序模拟隧道开挖过程沿开挖方向推进。本研究成果将在不久的将来以两篇期刊论文的形式发表在日本岩土学会（JGS）的《土壤与基础》上。少

Exploitation of underground space is vital to develop and/or redevelop the urban area. To make the underground space, tunneling methods such as shield tunnel and NATM have been often employed in urban area, instead of cut and cover methods, because of the restriction of environmental aspects and usage of ground surface and others. Urban tunnels usually are constructed in the shallow depth of the ground and sometimes have large cross-section. In the construction of such tunnels, we should pay much attention to the ground movement including surface settlements and the damage to the existing buildings as well as the earth pressure on the tunnels.This research has been carried out to investigate the ground movements and the earth pressures during shallow tunneling and devise proper and economic tunneling methods in urban area. For this purpose, we carried out elastoplastic unite element analyses in which the mechanical behavior of soils structures and interface between soil and structure a … More re properly taken into consideration, together with the corresponding model tests. Main contents of the present research can be summarized as follows :● Investigate the influence of soil cover on surface settlements and earth pressure due to tunnel excavation considering the ground as green field● Investigate the effects of existing super structures (building loads) in tunnel excavation.● Verify the response of different loading levels of existing super structure on ground deformation due to shallow tunnel excavation.● Investigate the influence of excavation sequences m surface settlements and earth pressure in case of large cross section and two or more parallel tunnels.● Characterize three-dimensional effects of tunnel excavation on surface settlements and earth pressure.● Simulate the advance of tunnel excavation process along the excavation direction in sequential way.The results of the present research will be published as two journal papers in "Soils and Foundations" of the Japanese Geotechnical Society (JGS) in near future. Less