广西岩溶塌陷区某中学教学楼地基灌浆加固处理工程实例

建于中细砂层上的多层教学楼,下伏灰岩岩溶发育,地下水活动剧烈,使用7 a后,室内外地面出现陷坑,楼两端也过量沉降.文中介绍了为抢险而进行的工程物探、钻探补充勘察,进而开展地基加固治理设计、施工及沉降变形观测,及时恢复了教学楼的使用,为既有建筑物在岩溶地质灾害发育区的勘察、治理设计及施工积累了工程经验。     

CFG桩加固的效应及其应用

对CFG桩单柱承载力和CFG桩复合地基承载力及其沉降进行了分析，讲座了CFG桩复合加固效应，以工程实例说明了CFG复合地基在工程中的应用。     

基坑降水总应力变化时有效应力增量和沉降量计算

针对基坑降水引起地面沉降计算值比实际值偏大的情况，本文系统分析了潜水和承压含水层在降水后，不同条件下土中总应力及有效应力的计算。基坑降水后土体中的总应力不是通常认为的一成不变。特别是基坑降水中常遇到的降低潜水含水层水头的情况，总应力是减小的，有效应力增量值也小于孔隙水压力下降值。对比分析了通常采用的不变原理和本文提出的可变原理两种情况，降水后土体总应力和有效应力增量计算值有差异，采用分层总和法计算了基于两种原理的沉降量。潜水含水土层沉降量计算偏差最大，基于总应力不变的沉降量比总应力可变的计算沉降量约大20%。本文计算原理对于抽取深层承压地下水导致地面沉降同样适用。     

沉降监测基准网与监测网精度探讨

为了保证建筑物在沉降过程中变形观测点的观测成果的连续性、可比性，对沉降监测中基准网与监测网的观测精度匹配问题进行了详细的探讨，得出了有参考价值的结论。     

Book Reviews

Books reviewed:
Roderick P. Neumann, Imposing Wilderness: Struggles over Livelihood and Nature Preservation in Africa
Richard A. Schroeder, Shady Practices: Agroforestry and Gender Politics in The Gambia
Adebayo Adedeji (ed.), Comprehending and Mastering African Conflicts: The Search for Sustainable Peaceand Good Governance
Hilgard O'Reilly Sternberg, A água e o homem na várzea do Careiro     

Simulating Icelandic vegetation cover during the Holocene Implications for long-term land degradation

We have simulated the spatial relationship between temperature change and long-term potential vegetation cover dynamics. The results show that the potential vegetation and birch forest range is highly sensitive to the temperature conditions. Around 3000 BP the simulated potential vegetation cover began to decrease and at the time of the Viking settlement, in AD 874 (1076 BP ), vegetation and forest cover was already in decline. The climate driven decline continued to an unprecedented low potential for vegetation for the Holocene that lasted c. 600 years, i.e. between AD c . 1300 and 1900. These interpretations are further supported by geomorphological and pollen data.     

Geomorphological observations and related natural hazards using merged remotely sensed data: a case study in the Corinthos area (NE Peloponnese, S. Greece)

Natural hazards are mostly related to the activation of combined geomorphological and geological processes that control landform development. The study area is located in the NE part of Peloponnese (Corinthos prefecture). It is a typical agricultural area with intense relief, the result of active tectonics and important human intervention. This study demonstrates the benefits from the synergism of SAR data (ERS-2) and optical data (SPOT2-XS) in order to highlight the possible natural-hazardprone areas. These data give different and complementary information since the radar signal depends mostly on topography, surface roughness and soil moisture, whereas the visible/infrared channels provide spectral information mostly on vegetation and land use/cover. The application presented here was focused on the enhancement of the high erosion risk areas, the improvement of the terrain interpretation, the mapping and highlighting of the landform morphology, and a more accurate determination of the main factors that control the flooding risk of Corinthos town.     

钻井岩粉在钻井液中自由沉降的实验研究─—岩粉的沉降阻力系数及沉降速度

利用模拟岩屑分别在淡水、ＣＭＣ钻井液以及用于德国大陆超深井的ＫＴＢ钻井液中进行了沉降实验并测定了岩屑的沉降速度。观测到两种不同的沉降方式－稳定沉降、摇摆沉降。岩屑的沉降方式与岩屑的雷诺数有关。     

不等时距的灰色模型预测

本文就实际观测中的不等时距情况进行了讨论，经过变换，将等时距的GM（1，1）模型，转为不等时距的GM（1,1）模型，进行预测．并经过残差修正，提高预测精度．     

A laboratory investigation into the settlement of a foundation on geogrid-reinforced sand due to cyclic load

Summary Laboratory model test results for permanent settlement of a shallow square foundation supported by geogrid-reinforced sand and subjected to cyclic loading are presented. During the application of the cyclic load, the foundation was subjected to a sustained static load. Tests were conducted with only one type of geogrid and at one relative density of compaction of sand. Based on the model test results, the nature of variation of the permanent settlement of the foundation with the intensity of the static loading and the amplitude of the cyclic load intensity are presented in a non-dimensional form.