基坑防渗体局部失效渗流场变化特征

采用三维有限元方法分析了基坑开挖工程在防渗体出现局部失效情况下，引起渗流在失效部位的集中及渗流场空间状况。提出了以一维通道嵌入三维块体的方法模拟管涌发展过程及渗流场变化特征。讨论了管涌通道渗透性对基坑管涌发展规律的影响。     

沉管灌注桩大面积断桩原因分析

通过2个工程实例分析了沉管灌注桩出现大面积断桩的原因是由于后期基坑开挖不当造成的，并提出了预防断桩出现的一些措施以及对断桩的处理补救措施。     

浙江江山石鼓水库除险加固工程技术措施

根据浙江江山石鼓水库大坝的结构构造特点、水库地质条件以及水库病险原因与状况，制定出一套科学完善的病险水库除险加固工程技术措施和施工操作规程，对病险水库进行了全面彻底治理，并取得良好效果。详细介绍了工程病险状况，除险加固方案设计，施工工艺及操作规程，加固效果检测及评价等。     

北方农牧交错带退耕还林还草经济政策优化调控

退耕还林还草作为北方农牧交错带生态重建的切入点,在实际操作中也不可避免地存在一定的问题。文章对当前退耕还林还草的社会经济特征、政策安排、协调机制及制约因素进行了分析。提出:区域粮食适度自给定位、部门协调机制创新、产权制度改革、区域产业专业化分工、适度生态移民及建立生态补偿机制为进行政策优化调控的主要途径。     

The role of baseflow in dissolved solids delivery to streams in the Upper Colorado River Basin

Salinity has a major effect on water users in the Colorado River Basin, estimated to cause almost $300 million per year in economic damages. The Colorado River Basin Salinity Control Program implements and manages projects to reduce salinity loads, investing millions of dollars per year in irrigation upgrades, canal projects, and other mitigation strategies. To inform and improve mitigation efforts, there is a need to better understand sources of salinity to streams and how salinity has changed over time. This study explores salinity in the baseflow fraction of streamflow, assessing whether groundwater is a significant contributor of dissolved solids to streams in the Upper Colorado River Basin (UCRB). Chemical hydrograph separation was used to estimate baseflow discharge and baseflow dissolved solids loads at stream gages (n = 69) across the UCRB. On average, it is estimated that 89% of dissolved solids loads originate from the baseflow fraction of streamflow, indicating that subsurface transport processes play a dominant role in delivering dissolved solids to streams in the UCRB. A statistical trend analysis using weighted regressions on time, discharge, and season was used to evaluate changes in baseflow dissolved solids loads in streams (n = 27) from 1986 to 2011. Decreasing trends in baseflow dissolved solids loads were observed at 63% of streams. At the three most downstream sites, Green River at Green River, UT, Colorado River at Cisco, UT, and the San Juan River near Bluff, UT, baseflow dissolved solids loads decreased by a combined 823,000 metric tons (mT), which is approximately 69% of projected basin‐scale decreases in total dissolved solids loads as a result of salinity control efforts. Decreasing trends in baseflow dissolved solids loads suggest that salinity mitigation projects, landscape changes, and/or climate are reducing dissolved solids transported to streams through the subsurface. Notably, the pace and extent of decreases in baseflow dissolved solids loads declined during the most recent decade; average decreasing loads during the 2000s (28,200 mT) were only 54% of average decreasing loads in the 1990s (51,700 mT).     

Modeling the 2D behavior of dry‐stone retaining walls by a fully discrete element method

The dry‐stone retaining walls (DSRW) have been tipped as a promising solution for sustainable development. However, before recently, their behavior is relatively obscure. In this study, discrete element method (DEM) approach was applied to simulate the plane strain failure of these walls. A commercial DEM package (PFC2D™) was used throughout this study. The authors used a fully discrete approach; thus, both the wall and the backfill were modeled as discrete elements. The methodology for obtaining the micromechanical parameters was discussed in detail; this includes the three mechanical sub‐systems of DSRWs: wall, backfill and interface. The models were loaded progressively until failure, and then the results were compared with the full‐scale experimental results where the walls were loaded, respectively, with hydrostatic load and backfill. Despite its complexity and its intensive calculation time, DEM model can then be used to validate a more simplified approach. Copyright © 2015 John Wiley & Sons, Ltd.     

Retaining wall optimization using interior search algorithm with different bound constraint handling

Along with the applicability of optimization algorithms, there are lots of features that can affect the functioning of the optimization techniques. The main purpose of this paper is investigating the significance of boundary constraint handling (BCH) schemes on the performance of optimization algorithms. To this end, numbers of deterministic and probabilistic BCH approaches are applied to one of the most recent proposed optimization techniques, named interior search algorithm (ISA). Apart from the implementing different BCH methods, a sensitivity analysis is conducted to find an appropriate setting for the only parameter of ISA. Concrete cantilever retaining wall design as one of the most important geotechnical problems is tackled to declare proficiency of the ISA algorithm, on the one hand, and benchmark the effect of BCH schemes on the final results, on the contrary. As results demonstrate, various BCH approaches have a perceptible impact on the algorithm performance. In like manner, the essential parameter of ISA can also play a pivotal role in this algorithm's efficiency. Copyright © 2017 John Wiley & Sons, Ltd.     

2000～2015年会理县地表覆盖变化监测

以LandSat多时相影像为数据源,采用基于规则的面向对象分类方法,监测会理县2000～ 2015年地表覆盖变化.结合1∶50 000 DEM数据,分析了会理县地表覆盖构成与转移、变化动态度及潜在退耕地情况.监测分析结论能为会理县加强空间管制、促进土地资源集约利用、指导生态文明建设等提供决策信息支撑.     

Rights in places: An analytical extension of the right to the city

Following recent scholarship on place and place-making, we identify key challenges for contemporary empirical research using the “Right to the City” as an analytic. We seek to distinguish between the aspirational “right” articulated as a political and conceptual call to arms on one hand, and the “actually existing rights” that are carved out through both formal and informal mechanisms (including political protest) in the everyday city on the other. Actually existing rights are defined not through fiat or via momentary revolutionary acts, but through the durability of relationships between multiple actors, including residents, citizens, states, and corporate agents. We re-articulate urban rights as actually contingent and agonistic properties of the relationships that citizens have with places. This paper uses the historic conflict over community gardens in New York as an illustration of how thinking of rights regimes as multiple, overlapping, and placed helps better illuminate potential political interventions. Thinking of rights and places as plural, overlapping, and contingent is analytically productive because it highlights (rather than overwriting) conflicts between competing articulations of rights and privileges in cities.     

Public views on economic growth,the environment and prosperity: Results of a questionnaire survey

The long-standing academic and public debate on economic growth, prosperity and environmental sustainability has recently gained new momentum. It lacks, however, a broad perspective on public opinion. Prior opinion surveys typically offered a simple dichotomous choice between growth and environmental protection. This study examines public beliefs and attitudes about a wider range of aspects of the growth debate. To this end, we conducted an online questionnaire survey including a country-wide, representative sample of 1008 Spanish citizens. Using factor analysis, we identify six distinct dimensions of public attitudes, referred to as: prosperity with growth; environmental limits to growth; general optimism; wrong priority; overrated GDP; and governmental control. We further analyze several specific questions associated with the growth debate, such as those concerning the desired GDP growth rate, the preferred growth-environment position, and beliefs about, as well as reasons for, a possible end or continuation of growth. We find that most respondents favor GDP growth rates of more than 3%. A majority views growth and environmental sustainability as compatible (green growth), while about one-third prefers either ignoring growth as a policy aim (agrowth), or stopping it altogether (degrowth). Only very few people want growth unconditionally (growth-at-all-costs). About one-third of the respondents believe that growth may be never-ending. We examine how support for or disagreement with different statements on growth are related to each other, as well as how they are influenced by socio-demographic, knowledge and ideology/values variables. Overall, our findings can inform public debates about the growth paradigm and its potential alternatives by providing a more nuanced understanding of public opinion. We make suggestions for future research, including modifying poll questions on growth and environment through offering a more diverse set of response options.