Modelling of long-term ground response to tunnelling under St James's Park, London

Following a tunnel excavation in low-permeability soil, it is commonly observed that the ground surface continues to settle and ground loading on the tunnel lining changes, as the pore pressures in the ground approach a new equilibrium condition. The monitored ground response following the tunnelling under St James's Park, London, shows that the mechanism of subsurface deformation is composed of three different zones: swelling, consolidation and rigid body movement. The swelling took place in a confined zone above the tunnel crown, extending vertically to approximately 5 m above it. On the sides of the tunnel, the consolidation of the soil occurred in the zone primarily within the tunnel horizon, from the shoulder to just beneath the invert, and extending laterally to a large offset from the tunnel centreline. Above these swelling and consolidation zones the soil moved downward as a rigid body. In this study, soil-fluid coupled three-dimensional finite element analyses were performed to simulate the mechanism of long-term ground response monitored at St James's Park. An advanced critical state soil model, which can simulate the behaviour of London Clay in both drained and undrained conditions, was adopted for the analyses. The analysis results are discussed and compared with the field monitoring data. It is found that the observed mechanism of long-term subsurface ground and tunnel lining response at St James's Park can be simulated accurately only when stiffness anisotropy, the variation of permeability between different units within the London Clay and non-uniform drainage conditions for the tunnel lining are considered. This has important implications for future prediction of the long-term behaviour of tunnels in clays.

亚洲南部球果蝠Sphaerias blanfordi(Thomas,1891)的亚种分化

球果蝠Sphaerias blanfordi(Thomas,1891)是亚洲南部喜马拉雅-印度支那地区的特有种,甚为罕见而少有报道.曾被认为是单型种,几乎无雄性特征的描述.蔡桂全和张遁治(1980)根据采自西藏东南部墨脱的2只雄性标本订了一亚种一墨脱亚种Sphaerias blanfordi motuoensis,其主要特征是颈下侧有一对灰黄色的圆形毛斑.中国科学院昆明动物研究所先后在云南西北部高黎贡山地区采获25号标本(9♂♂,16♀♀),发现球果蝠两性在外形上有明显的性别差异,雄性的颈下侧有一对圆形、灰黄色的刷状毛斑,但雌性均无;对比墨脱标本,认为墨脱亚种的鉴别特征不可靠,亚种不能成立.Lunde(2003)曾报道采自越南北部Mt.Tay Con Linh Ⅱ地区的43号标本,其前臂长和上犬齿外宽明显与印度、缅甸和云南西北部高黎贡山地区的标本不同,可能是真正的地理亚种.

Numerical simulation of long-term twin-tunnel behaviour at St James's park

The twin-tunnel construction of the Jubilee Line Extension tunnels beneath St James's Park was simulated using coupled-consolidation finite-element analyses. The effect of defining different permeabilities for the final consolidation stage was investigated, and the performance of a fissure softening model was also evaluated. The analyses suggested an unexpectedly high permeability anisotropy for soil around the tunnel crown, possibly due to stress-induced permeability changes, or low-permeability laminations. Also, the permeability profile and lining conductivity were found to differ between the tunnels. Inclusion of the fissure model gave a narrower settlement trough, more alike that in the field, by preferentially softening simple shear behaviour. Long-term settlements at the site continue to increase at an unexpectedly high rate, suggesting the possibility of creep or unexpected soil softening during excavation. © 2012 Taylor & Francis Group.

James Joyce and the Problem of Psychoanalysis

Thurston, L. (2004). James Joyce and the Problem of Psychoanalysis. Cambridge: Cambridge University Press. RAE2008

Meibion Afradlon a Chymeriadau Eraill: Golwg ar y Dymer Delynegol, 1891-1940

Chapman, T. (2004). Meibion Afradlon a Chymeriadau Eraill: Golwg ar y Dymer Delynegol, 1891-1940. Caerdydd: Gwasg Prifysgol Cymru.

Robert Heinich, Michael Molenda, James D. Russell, Sharon E. Smaldino, Instructional Media and Technologies for Learning, Prentice-Hall, Inc., Englewood Cliffs, New Jersey 1996, ss. 446. Steven Hackbarth, The Educational Technology Handbook. A Comprehensive Guide, Educational Technology Publications Inc., Englewood Cliffs, New Jersey 1996, ss. 351

Recenzje i sprawozdania z książek

An address delivered on the occasion of the funeral of the Rev. William James

Address

In Memoriam James William McFerrin

Memoriam.

A Collection of Memorial Addresses about the Death of James A. Garfield

Printed pamphlet of sermons presented by ministers and pastors after the death of President James A. Garfield.

Indian and white in the Northwest : a history of Catholicity in Montana, 1831-1891 / by L.B. Palladino ; with an introduction by John B. Brondel.

http://www.archive.org/details/indianandwhite00palliala

The pastor's missionary manual.

Boston University Theology Library

Thoughts from modern martyrs/ edited and arranged by James Anthony Walsh.

http://www.archive.org/details/thoughtsfrommode00walsuoft

Daybreak in Livingstonia; the story of the Livingstonia mission, British Central Africa, by James W. Jack.

http://www.archive.org/details/daybreakinliving011984mbp

Human progress through missions / by James L. Barton.

http://www.archive.org/details/humanprogressthr00bartuoft

James Evans : inventor of the syllabic system of the Cree language / by John McLean ... (Robin Rustler).

http://www.archive.org/details/jamesevans00maclrich