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41.
《工程(英文)》2017,3(6):863-870
The history of the formation of the alpine region is affected by the activities of the glaciers, which have a strong influence on underground works in this area. Mechanized tunneling must adapt to the presence of sound and altered rock, as well as to inhomogeneous soil layers that range from permeable gravel to soft clay sediments along the same tunnel. This article focuses on past experiences with tunnel-boring machines (TBMs) in Switzerland, and specifically on the aspects of soil conditioning during a passage through inhomogeneous soft soils. Most tunnels in the past were drilled using the slurry mode (SM), in which the application of different additives was mainly limited to difficult zones of high permeability and stoppages for tool change and modification. For drillings with the less common earth pressure balanced mode (EPBM), continuous foam conditioning and the additional use of polymer and bentonite have proven to be successful. The use of conditioning additives led to new challenges during separation of the slurries (for SM) and disposal of the excavated soil (for EPBM). If the disposal of chemically treated soft soil material from the earth pressure balanced (EPB) drive in a manner that is compliant with environmental legislation is considered early on in the design and evaluation of the excavation mode, the EPBM can be beneficial for tunnels bored in glacial deposits. 相似文献
42.
该文从深入剖析福建土楼侨福楼个案出发,指出了土楼的3点特质和分析了福建圆楼的3点主要设计元素,并以列举的2个实例说明了这些设计元素正是我们可以继承创新之所在。 相似文献
43.
Milica Topalovic 《Architectural Design》2016,86(4):42-47
The explosion of the palm oil industry in recent decades has transformed vast swathes of the Malaysian and Indonesian countryside. Milica Topalovic , Assistant Professor of Architecture and Territorial Planning at ETH Zurich, asserts that the resulting agro-industrial landscapes challenge the very concept of what is rural, and considers how such areas should be conceptualised. 相似文献
44.
Roberta L Bondar 《Architectural Design》2015,85(4):98-99
‘By 2050 we will have probed the universe even further, peeling back time as we strive for some sense of creation and meaning.’ The world's first neurologist in space, Roberta L Bondar , who conducted international experiments on space mission STS 42 and has subsequently undertaken neurological research with NASA, urges us to look up and into space, which is set to remain a rich area of exploration, scientific investigation and wonder, with the discovery of new planets, light, patterns and materials on the not-so-distant horizon. 相似文献
45.
Felicity D Scott 《Architectural Design》2015,85(3):78-85
Felicity D Scott , Associate Professor of Architecture at Columbia University Graduate School of Architecture, Planning and Preservation (GSAPP), describes here the instant city events of the early 1970s. These foreshadowed current global village media practices in what now seems a quaintly material manner: communication between sites involved the physical mailing of videotapes and ‘wire photos’ through the postal service. The sites themselves – in the US and elsewhere – were transformed into ‘instant cities’ through the erection of physical geodesic domes, teepees and inflatables in seas of mud. The true antecedents of today's instant networking, these pioneers embraced the newest technology available at the time and the most innovative forms of temporary architecture. 相似文献
46.
生土民居是劳动人民在生产力尚不发达的情况下,结合当地气候、地质和地域材料等自然条件的杰出营造。生土民居无论是在气候炎热的南方还是在寒冷的北方都体现出了良好的环境适应性和宜居性。在我国众多的生土民居中,窑洞是我国西北极具特色的生土民居体系。本文通过对它的产生条件、使用功能、空间形态、和建筑艺术等方面进行其宜居性的分析,探索传统民居的价值。 相似文献
47.
As one of the measures for slope fast reinforcement, micropiles are always designed as a group. In this paper, an analytic model for the ultimate resistance of micropile is proposed, based on a beam–column equation and an existing p–y curve method. As such, an iterative process to find the bending moment and shear capacity of the micropile section has been developed. The formulation for calculating the inner force and deflection of the micropile using the finite difference method is derived. Special attention is given to determine the spacing of micropiles with the aim of achieving the ultimate shear capacity of the micropile group. Thus, a new design method for micropiles for earth slope stabilization is proposed that includes details about choosing a location for the micropiles within the existing slope, selecting micropile cross section, estimating the length of the micropile, evaluating the shear capacity of the micropiles group, calculating the spacing required to provide force to stabilize the slope and the design of the concrete cap beam. The application of the method to an embankment landslide in Qinghai province, China, is described, and monitoring data indicated that slope movement had effectively ceased as a result of the slope stabilization measure, which verified the effectiveness of the design method. 相似文献
48.
49.
红外地球敏感器广泛运用空间飞行器,尤其是在地球轨道附近。目前最新的静态地球敏感器使用焦平面探测器来覆盖整个地球红外辐射圆。若面向飞行在70km-100km处的临近空间飞行器,他们就需要有很大的视场(>120°)且相对分辨率很低。本文针对临近空间飞行器的天文导航运用,采用线阵CCD作为探测器,设计了一个三视场红外地球敏感器。他们按照二维角度均匀分布以确保每个光学头能够均匀的指向地球红外辐射圆上。每个CCD覆盖20°以便能够精确地分辨地球辐射和空间的边界点。综合考虑地球辐射模型和地球扁率等因素,利用地球敏感器观测的向量可以获得地心矢量和飞行高度。以70-100km飞行高度为示例,建立相应的数学模型,同时提出了相应的姿态和高度确定算法并进行了仿真。综上述分析,研制了一套三视场地球敏感器原理样机并进行相关测试。仿真和实验结果表明:高度测量精度优于200m,姿态测量精度优于0.002°。 相似文献
50.
《Soils and Foundations》2019,59(6):2206-2219
Soil-cement columns are widely used to improve soft ground, and the bearing capacity of the formed composite ground is a key design parameter. The currently employed design method was developed for composite grounds under rigid footings, whilst the bearing capacity behavior of composite grounds under earth fills with different degrees of stiffness has rarely been investigated. Hence, the present study attempts to fill this gap. In this investigation, 1-g laboratory model tests are conducted to compare the bearing capacity behavior of composite grounds under a rigid footing and under embankment fill, based on which a numerical model that can capture the strain-softening behavior of soil-cement columns is established. The calibrated numerical model is further employed to perform 144 analyses. The results indicate that the failure mode of composite grounds differs for different types of earth fills: soil failure occurs prior to column failure under soft clay and dredged slurry, whereas column failure is the primary failure mode for composite grounds under embankment fill. This difference in failure mode of composite grounds can be explained using soil arching theories. For different failure modes, different bearing capacity efficiency factors should be used in design. 相似文献