Complications for traditional land consolidation in Central Europe

An integral part of post-socialist transformation under the Washington Consensus has been the privatisation of previously state owned and/or co-operative farms. In many instances, there have been attempts at ‘turning back the clock’ to pre-War conditions, including land ownership structures. Frequently, the result has been the division of large, economically efficient units into numerous, small and economically barely viable private plots. Following accession to the European Union, these re-constituted peasant-scale structures pose a major challenge to the Union’s agricultural policy. As this paper demonstrates, a simple transfer of western European practices, such as land consolidation, is not possible. The particular legacies of the communist system have given land ownership particular values, legitimacy and personal identity, and emotional bonds. Simple technocratic solutions, as applied in the West earlier, are thus not feasible. Consequently, the paper points out, new forms and instruments of tackling disadvantageous agricultural structures need to be found.     

江苏镇江焦山索道上站滑坡治理中技术方法的应用

镇江市是江苏省滑坡地质灾害较为严重的城市,其地质灾害防治工作开展较早,积累了一定的防治管理经验。而焦山索道上站滑坡治理工程是多种滑坡治理技术方法和措施的综合应用,通过混凝土抗滑桩、锚索、锚杆、排水以及挂网喷播复绿等技术方式和措施的应用,成功地完成了焦山索道上站的滑坡治理工程,为镇江市其他滑坡地质灾害的治理提供了一定的参考借鉴作用。     

水源井同径套、筛管封井止水工艺

水源供水井，在封井止水下艺中，始终存在封井质量、水泥固结质量及井内钻具事故等风险，为此在对准格尔旗施工的10口水源供水井施工中，制作了单向逆止阀水泥封隔器，并与Ф340套、筛管用吊卡按一定顺序下入井内。该装置的使用，有效地提高了封井止水的质量。     

帷幕灌浆在坝基防渗处理中的应用——以新疆乌什水水库为例

新疆乌什水水库为注入式水库。于1984年始修,总库容3850×104m3,灌溉下游农田。因坝基严重渗漏,2002年被新疆水利专家评为险库,对坝基需进行防渗帷幕灌浆处理。为此,设计和施工中确定了坝基防渗处理原则,从而探索出一套最佳的灌浆工艺。现场运用多种手段对灌浆质量进行全面检查,对施工全过程实施质量控制和跟踪监理,使施工的838个灌浆孔(总进尺25804.18m)的优良率达84.8%,7个固结灌浆单元和21个帷幕灌浆单元工程合格率达100%。固结灌浆和帷幕灌浆部分工程及坝基防渗帷幕单位工程均被评为优良工程。     

土地开发整理项日管理信息系统建设

本文首先分析了我国土地开发整理的地位和现状,回顾了“十五”期间我国在土地开发整理方面做出的巨大的成绩,展望了“十一五”期间我国在土地整理工作上的投入力度和方向。在此基础上,对我国土地整理工作所采用的技术手段进行了分析,提出了实施土地开发整理工作的信息化是解决目前存在问题的有效措施,为了保证国家每年投资数十亿资金的土地开发整理项目从审查到实施各个环节的科学性和规范性,迫切要求充分利用计算机技术、网络通信技术和3S技术等先进手段加强项目的全程管理。接着,对“国家投资土地开发整理项目管理信息系统”从功能角度进行了详细的阐述,将系统划分为若干个子系统进行开发,并对一些子系统的功能进行了阐述。最后介绍了系统的应用情况。     

单管分喷法在地基加固中的应用

介绍了单管分喷法在地基加固中的施工技术、工艺。该方法具有设备简单、质量可靠、工期短、造价低等优点。     

强夯地基效应及加固机制浅析

强夯地基效应,是指经强夯处理使地基土的结构形式,强度和变形大小,及其作用过程发生的改变。通过对强夯过程中一系列的现象分析,揭示强夯地基效应的形成机制,对强夯地基效应的三个方面及其之间的联系进行分析,其结论对于强夯处理设计和加固机制的认识有较大意义。     

Importance of footing–soil separation on dynamic stiffness of piled embedded footings

Different phenomena such as soil consolidation, erosion, and scour beneath an embedded footing supported on piles may lead to loss of contact between soil and the pile cap underside. The importance of this separation on the dynamic stiffness and damping of the foundation is assessed in this work. To this end, a numerical parametric analysis in the frequency domain is performed using a rigorous three‐dimensional elastodynamic boundary element–finite element coupling scheme. Dimensionless plots relating dynamic stiffness functions computed with and without separation effects are presented for different pile–soil configurations. Vertical, horizontal and rocking modes of oscillation are analyzed for a wide range of dimensionless frequencies. It is shown that the importance of separation is negligible for frequencies below those for which dynamic pile group effects start to become apparent. Redistribution of stiffness contributions between piles and footing is also addressed. Copyright © 2009 John Wiley & Sons, Ltd.     

Coupled HM analysis using zero‐thickness interface elements with double nodes—Part II: Verification and application

In a companion Part I of this paper (Int. J. Numer. Anal. Meth. Geomech. 2008; DOI: 10.1002/nag.735 ), a coupled hydro‐mechanical (HM) formulation for geomaterials with discontinuities based on the finite element method (FEM) with double‐node, zero‐thickness interface elements was developed and presented. This Part II paper includes the numerical solution of basic practical problems using both the staggered and the fully coupled approaches. A first group of simulations, based on the classical consolidation problem with an added vertical discontinuity, is used to compare both the approaches in terms of accuracy and convergence. The monolithic or fully coupled scheme is also used in an application example studying the influence of a horizontal joint in the performance of a reservoir subject to fluid extraction. Results include a comparison with other numerical solutions from the literature and a sensitivity analysis of the mechanical parameters of the discontinuity. Some simulations are also run using both a full non‐symmetric and a simplified symmetric Jacobian matrix. On top of verifying the model developed and its capability to reflect the conductivity changes of the interface with aperture changes, the results presented also lead to interesting observations of the numerical performance of the methods implemented. Copyright © 2008 John Wiley & Sons, Ltd.     

Identifying parameters controlling soil delayed behaviour from laboratory and in situ pressuremeter testing

The aim of this paper is to present a methodology for identifying the soil parameters controlling the delayed behaviour from laboratory and in situ pressuremeter tests by using an elasto‐viscoplastic model (EVP‐MCC) based on Perzyna's overstress theory and on the elasto‐plastic Modified Cam Clay model. The influence of both the model parameters and the soil permeability was studied under the loading condition of pressuremeter tests by coupling the proposed model equations with Biot's consolidation theory. On the basis of the parametric study, a methodology for identifying model parameters and soil permeability by inverse analysis from three levels of constant strain rate pressuremeter tests was then proposed and applied on tests performed on natural Saint‐Herblain clay. The methodology was validated by comparing the optimized values of soil parameters and the values of the same parameters obtained from laboratory test results, and also by using the identified parameters to simulate other tests on the same samples. The analysis of the drainage condition and the strain rate effect during a pressuremeter test demonstrated the coupled influence of consolidation and viscous effects on the test results. The numerical results also showed that the inverse analysis procedure could successfully determine the parameters controlling the time‐dependent soil behaviour. Copyright © 2008 John Wiley & Sons, Ltd.