Wu M.,Hebei University of Technology |
Zhao X.,Hebei University of Technology |
Liu K.,Hebei University of Technology |
Wang C.L.,Sinoma Energy Conservation Ltd. |
Geng H.X.,Tianjin Branch Company
Applied Mechanics and Materials | Year: 2013
A deep foundation pit project in Changsha City covers an area of about 63000m2, the largest excavation depth of the pit is 16.2 m, so it belongs to the deep and large foundation supporting engineering. By comprehensive analysis of the proposed construction site environment conditions and engineering geological conditions the different combined supporting schemes are adopted in different domains separately. In this paper the design schemes of the combined supporting technology are introduced. The problems encountered in the excavation construction process and the corresponding measures being taken are analyzed in detail. The results show that the design scheme is reasonable. Both horizontal displacement and settlement can meet specification and design requirements. At the same time the reasonable construction organization makes the support engineering be finished within the scheduled term, which saves the precious time for the following construction procedure. Furthermore it provides guidance for similar projects. © (2013) Trans Tech Pudlications, Switzerland.
Zhou X.,Tianjin Branch Company |
Wang Q.,Tianjin Branch Company |
Li J.,Tianjin Branch Company |
Zang C.,Energy Research Company |
And 2 more authors.
Energy Exploration and Exploitation | Year: 2012
In this paper, the origin and accumulation time of CO 2, and the transformation of clastic reservoir bed by CO 2 in the A2 structure at the actic area of Qin Nan Sag were studied. The elevated δ 13C CO2, R/Ra values and 40Ar/ 36Ar values showed that CO 2 was mantle derived. CO 2-bearing inclusions were associated with hydrocarbon inclusions, and CO 2-bearing inclusions included hydrocarbon components, showing migration and filling of CO 2 and hydrocarbon at the same stage. Basin modeling and homogenization temperature of inclusions indicated that the time of hydrocarbon and CO 2 accumulation was mainly less than 3 Ma. CO 2 late filling resulted in strong dissolution of feldspar and carbonate cement, with a high content of intragranular dissolution pores and a high proportion of intergranular primary pores, mostly from carbonate cement dissolution. Acidic environment inhibited illite growth, and dissolution of feldspar and acidic environment promoted formation of kaolinite. CO 2 late filling brought out obvious thermal fluctuation, which was in favor of redistribution of dissolved matter, and top strong cementation was found at rock cores. Because of late accumulation of CO 2, acidic environment of reservoir bed lasting for a long time, reservoir bed at a high temperature, undergrown dawsonite showed weak influence on reservoir bed quality. Dissolution of feldspar and carbonate cement, inhibition of illite growth, a high content of authigenic kaolinite, a low content of dawsonite, and redistribution of dissolved matter played a decisive role in improving reservoir quality, with rarely seen high permeability.