某市软弱地层中盾构掘进地表沉降数据分析

某市轨道6号线潘林区间盾构过程地层软弱,本文通过将盾构过程监控量测的地表沉降与地层条件对比,得出盾构在均一土层中掘进,即使是土层软弱,易控制盾构参数,周边地表反应平稳;盾构在多重地层中掘进,难以控制土压、盾构姿态等参数,易造成出渣不平衡,周边环境反应强烈;掘进过程遇到上覆或下伏淤泥质土时,一定要注意淤泥涌入土仓,造成地表变形过大,必要时可以提前加固.本文体现监控量测数据与地层情况的良好对应性.     

软土地层盾构隧道管片上浮规律及控制研究

在采用盾构法施工的隧道中,管片上浮是经常会发生的现象,地层条件、同步注浆、盾构姿态等因素都会引起管片上浮,本文结合台州市域铁路某盾构区间隧道工程实例,分析了盾构管片上浮的规律,在台州软土地层中,盾构管片上浮较为明显,上覆较厚(3)1黄黏土的区段,盾构管片上浮量较大,在施工过程中,应使盾构机保持负姿态掘进,在上覆较厚(3)1黄黏土区段应采取降低盾构施工速度、控制盾构姿态、减小水泥砂浆水灰比、增大水泥用量等措施控制盾构管片上浮.     

城市道路软基处理方法探讨

软土是指以水下沉积的软弱粘性土或淤泥为主的地层,有时也夹有少量的腐泥或泥炭层。主要时城市道路软土地基处理的方式方法进行了分析探讨。     

冷冻法施工技术在盾构区间联络通道施工中的应用研究

在软土地区盾构施工过程中，常遇到淤泥或淤泥质黏土层，盾构区间联络通道开挖施工前就需要对土体进行加固，以提高其强度和稳定性，保证施工安全性。本文以台州地区第一条市域铁路工程为例，采用冷冻法施工技术对联络通道软弱土体加固，研究冷冻法施工工艺，并对冷冻效果进行统计分析，得出软土冷冻后可以满足开挖强度要求，说明采用冷冻法施工可以满足台州软弱土体联络通道施工要求及安全性，可为下一步开挖施工提供技术支撑，也为同类软土地区工程施工提供借鉴参考。     

承压水砂层盾构钢套筒接收施工技术

盾构接收是盾构施工的关键工序,富水软土地层中,随着隧道埋深的增加,盾构接收的施工难度及风险也越来越大。本文根据天津地铁6号线承压水砂层中既有运营线地下三层车站盾构接收为例,采用"地面水泥系加固、站内钢套筒接收"的施工方法,安全、顺利地完成了盾构接收,确保了隧道和周边环境的安全,可为日后类似工程施工提供借鉴。     

论述房屋建筑工程软地基处理

如果地基承载力不足,就可以判定为软弱地基,就必须采取措施对软弱地基进行处理。软弱地基系指主要由淤泥、淤泥质土、冲填土、杂填土或其他高压缩性土层构成的地基。在建筑地基的局部范围内有高压缩性土层时,应按局部软弱土层考虑。勘察时,应查明软弱土层的均匀性、组成、分布范围和土质情况,根据拟采用的地基处理方法提供相应参数。冲填土尚应了解排水固结条件。杂填土应查明堆积历史,明确自重下稳定性、湿陷性等基本因素。     

硬土层中盾构穿越建筑群时地表沉降控制技术

苏州轨道交通4号线4标火车站站~北寺塔站区间隧道穿越的土层主要为上软下硬的软硬土。施工过程中地表沉降累计在+10^-20mm之间,为了保证盾构机顺利穿越建筑群,对火车站站~北寺塔站区间盾构施工时地表沉降原因进行了详细的分析。通过使用新型材料——惰性聚氨酯,采取同步注浆和及时注浆相结合,上部软土层强注浆等方法,有效的控制了地表沉降值。     

谈公路工程施工中软土地基处理

软土是指以水下沉积的软弱粘性土或淤泥为主的地层,有时也夹有少量的腐泥或泥炭层。处理的目的是要提高软弱地基的强度,保证地基的稳定,降低软弱土的压缩性,减少基础的沉降和不均匀沉降。文中主要对公路施工中的软土地基处理的方式方法进行了分析探讨。     

海域超软土地层大直径盾构掘进控制研究

随着我国轨道交通事业的高速发展,穿江越海盾构工程逐年增加,地层稳定性分析及控制成为研究热点。本文以粤港澳大湾区横琴杧洲穿海盾构隧道工程为工程实例,通过PLAXIS 3D建立三维有限元模型,定量分析了盾构掘进过程加固范围、地表沉降等时变特征。结合现场实测数据,明确了海域超软土地层大直径盾构掘进过程中地层的变形规律,验证了数值模拟的可靠性。研究表明：盾构隧道开挖时,地表允许最大沉降为20mm,当t>0.15D,地表沉降满足要求,加固范围取0.20D最为合理,当t=0.00D时,地表最大沉降约50mm,当t=0.20D时,地表最大沉降约8mm,相比t=0.00D最大沉降减少约84%。结合研究结果所得规律,设计了盾构隧道软土地基加固方案,取得了理想效果。研究可为类似工程提供有价值的参考。     

富水软弱地层盾构区间近距离下穿既有运营地铁区间设计关键技术研究

新建地铁区间近距离下穿既有运营线路的情况越来越多，特别在富水软弱地层，地下水位高、土层压缩性高、承载力低，在下穿过程中极易造成既有区间结构较大变形，影响既有运营线路安全。本文以天津地铁4号线盾构区间近距离下穿既有9号线区间为例，通过采用合理的技术措施，保障了工程的顺利实施。此外，通过数值模拟分析了盾构下穿既有线时的变形情况，并与施工实测数据进行对比，变形趋势基本一致，可为后续类似工程提供参考。     

Consistency of a nonparametric estimation of a density functional

LetX be a random variable with distribution functionF and density functionf. Let ? and ψ be known measurable functions defined on the real lineR and the closed interval [0, 1], respectively. This paper proposes a smooth nonparametric estimate of the density functional \(\theta = \int\limits_R \phi (x) \psi \left[ {F (x)} \right]f^2 (x) dx\) based on a random sampleX ₁, ...,X _n fromF using a kernel functionk. The proposed estimate is given by \(\hat \theta = (n^2 a_n )^{ - 1} \mathop \sum \limits_{i = 1}^n \mathop \sum \limits_{j = 1}^n \phi (X_i ) \psi \left[ {\hat F (X_i )} \right]k\left[ {(X_i - X_j )/a_n } \right]\) , where \(\hat F(x) = n^{ - 1} \mathop \sum \limits_{i = 1}^n K\left[ {(x - X_i )/a_n } \right]\) with \(K (w) = \int\limits_{ - \infty }^w {k (u) } du\) . The estimate \(\hat \theta \) is shown to be consistent both in the weak and strong sense and is used to estimate the asymptotic relative efficiency of various nonparametric tests, with particular reference to those using the Chernoff-Savage statistic.     

Existence of a convex extension of a preference relation

In this paper we say that a preference (i.e. irreflexive) relationP isregular (or aweak order) if both it and its non-comparability relation are transitive; we also say that a preference relationP ^* is aconvex extension of another preference relationP ifP?P ^* holds andP ^* is regular and convex-valued. We prove that a convex extension ofP exists if and only if every non-empty and finite set of alternativesA is not included in the convex hull of ∪ _x∈A P(x).     

Simulation of a blood-inventory-bank system in a hospital

A blood-bank inventory system has been analysed viewing it as an inventory-hank system where the demand forecasting forms a part of the inventory model. A simulation model incorporating the “desired-beginning-inventory-level” policy has been used for the analysis of system-performance. Optimal inventory policy-guidelines have been suggested for a hospital blood-bank using blood shortage and blood out-dating as the two important components of the measure of effectiveness. Numerical results have been given.     

一个人和一本杂志的奇迹

曾经接近倒闭的台湾《商业周刊》在俞国定手中奇迹般地成为今天台湾业界发行量、广告额排名第一的杂志。他掌握了媒体成功的秘笈了吗?     

Calculating Cumulants of a Taylor Expansion of a Multivariate Function

A method, which we believe is simpler and more transparent than the one due to McCullagh (1984) , is described for obtaining the cumulants of a scalar multivariate stochastic Taylor expansion. Its generalisation is also suggested. An important feature, previously not reported, is that the expansion of every cumulant of order ≥ 2 is made up of separate subseries.
In order to handle certain frequently occurring sums over permutations of members of compound index sets, we introduce a new notation  [ m ]_*,  where   m   is a positive integer.     

On a two-step estimation of a multivariate logit model

In this article the author studies the properties of the two-step estimation method proposed by Domencich and McFadden (Urban Travel Demand, North-Holland, 1975) for a multivariate logit model and shows that it is consistent but asymptotically less efficient than the maximum likelihood estimator. Its computation, however, can be considerably simpler than that of the maximum likelihood estimator, especially in models involving several dependent variables.     

Developing a Continuous Space Representation of a Simulated Population

Abstract

Spatial microsimulation models typically match census of population data with survey data in order to simulate synthetic populations of individuals and households within small-scale geographic areas. For most spatial microsimulation applications this level of spatial precision is satisfactory. For others, more precise information on the location of simulated units may be required. To this end this paper develops a continuous space representation of a simulated population. It presents a statistical matching approach for assigning simulated households from a spatial microsimulation model to unique spatially-referenced residential locations. The allocation is based on a random assignment after splitting the simulated households into two groups: those predicted to reside in apartments and those predicted to reside in houses. The resulting ‘geohouseholds’ have a range of potential applications in economic and spatial analysis.

Création d'une représentation spatiale continue d'une population stimulée

Résumé Les modèles de microsimulation spatiale assortissent généralement les données de recensement de la population à des données de sondages, afin de simuler des populations synthétiques de particuliers et de foyers au sein de régions géographiques à échelle restreinte. Dans la plupart des applications de microsimulation spatiale, ce niveau de précision spatiale est satisfaisant. Dans d'autres, des informations plus précises sur l'emplacement d'unités simulées pourront s'avérer nécessaires. A cette fin, la présente communication crée une représentation spatiale continue d'une population simulée. Elle présente une méthode de correspondance statistique permettant d'affecter des foyers simulés, issus d'un modèle de microsimulation spatiale à des lieux résidentiels unique à référence spatiale. Cette allocation est basée sur une affectation aléatoire après la subdivision des foyers simulés en deux groupes : ceux dont on prévoit qu'ils résideront en appartement, et ceux dont on prévoit qu'ils résideront dans un maison. Les « géofoyers » résultants présentent toute une série d'applications potentielles pour les analyses économiques et spatiales.

Desarrollo de una representación espacial continua de una población simulada

Extracto Típicamente, los modelos de microsimulación espacial emparejan el censo de datos de la población con datos de encuestas, con objeto de simular poblaciones sintéticas de individuos y hogares dentro de áreas geográficas a pequeña escala. Para la mayoría de las aplicaciones de microsimulación espacial este nivel de precisión espacial es satisfactorio. Para otras, podría requerirse información más precisa sobre la ubicación de unidades simuladas. Con este objetivo, este trabajo desarrolla la representación espacial continua de una población simulada. Presenta un planteamiento de emparejamiento estadístico para asignar hogares simulados procedentes de un modelo de microsimulación espacial a ubicaciones residenciales únicas referenciadas espacialmente. La colocación se basa en una asignación al azar después de dividir los hogares simulados en dos grupos: los que se predice que residirán en apartamentos y los que se predice que residirán en casas. Los ‘geohogares’ resultantes ofrecen una gama de aplicaciones en potencia en el análisis económico y espacial.

     

Defining and measuring the development of a country over time: a proposal of a new index

This paper introduces the concept of harmonic growth as an extended acceptation of the notion of development, and discusses its measurement via the Harmonic Growth Index (HGI). The growth is seen as harmonic when the behaviour of a benchmark time series, which here is a measure of wealth, such as per capita GDP, is followed by a similar pattern in socio-economic series. Unlike most widely used indicators in the literature, which take into account the measurement of development over a single time, HGI measures the degree to which a social indicator’s time series pattern matches with the GDP’s. The index is a function, ranging in [0, 1], of the coefficients of the uniform B-splines fitted to each time series, according to the functional data framework. A case study on Mediterranean welfare countries (Greece, Italy, Portugal, and Spain), in the period 1996–2007, shows critical differences in the selected indicators which can be ascribed to their dissimilar specific development models. HGI can be also considered as a general index to measure the similarity between time patterns, or as an alternative to correlation for (non-necessarily linear) time series.     

Construction of a continuous utility function for a class of preferences

We construct a continuous utility indicator for a subclass of continuous preference relations, including some with thick indifference classes, using a measure theoretic technique related to that of Neuefeind (1972). This indicator is not continuous on the full class of continuous preferences endowed with the closed convergence topology. It appears that no such indicator can be constructed, although Mas-Colell (1975) has established that one exists. A finer topology for preferences seems appropriate.