水泥土(砼)抗压试件尺寸表面约束对强度的影响

推导了圆柱体试件和长（立）方体试件,分别在不同表面摩擦力和不同高宽（径）比下基于双剪屈服准则下抗压强度的理论计算公式,并与实验结果比较所得结果与实验结果甚为吻合。其理论计算与实验结果都说明,试件尺寸的不同与表面抹油与否对水泥土抗压强度均有一定的影响。其高宽（径）越大,其强度越低且越趋于一定值。试件上下表面不摸油其抗压强度略高抹油情况。     

The impact of ocean data assimilation on seasonal predictions based on the National Climate Center climate system model

An ensemble optimal interpolation (EnOI) data assimilation method is applied in the BCC_CSM1.1 to investigate the impact of ocean data assimilations on seasonal forecasts in an idealized twin experiment framework. Pseudo-observations of sea surface temperature (SST), sea surface height (SSH), sea surface salinity (SSS), temperature and salinity (T/S) profiles were first generated in a free model run. Then, a series of sensitivity tests initialized with predefined bias were conducted for a one-year period; this involved a free run (CTR) and seven assimilation runs. These tests allowed us to check the analysis field accuracy against the “truth”. As expected, data assimilation improved all investigated quantities; the joint assimilation of all variables gave more improved results than assimilating them separately. One-year predictions initialized from the seven runs and CTR were then conducted and compared. The forecasts initialized from joint assimilation of surface data produced comparable SST root mean square errors to that from assimilation of T/S profiles, but the assimilation of T/S profiles is crucial to reduce subsurface deficiencies. The ocean surface currents in the tropics were better predicted when initial conditions produced by assimilating T/S profiles, while surface data assimilation became more important at higher latitudes, particularly near the western boundary currents. The predictions of ocean heat content and mixed layer depth are significantly improved initialized from the joint assimilation of all the variables. Finally, a central Pacific El Ni?o was well predicted from the joint assimilation of surface data, indicating the importance of joint assimilation of SST, SSH, and SSS for ENSO predictions.     

区域地球系统模式研究进展

区域地球系统模式是区域气候模式下一阶段的主要发展目标。本文阐述了发展区域地球系统模式的重要意义,分析了近年来区域地球系统模式的研究进展和典型案例,指出其多圈层通量耦合、空间分辨率提高以及耦合数据同化的三个共性特征。建议以开源共创的方式整合各界研究力量,加快建设我国自主可控的区域地球系统模式;围绕新建立的模式开展跨学科研究,特别关注其中多圈层、多尺度过程的相互作用;围绕高分辨率区域地球系统模式建立区域数字孪生监测预警平台,用于关键区域的防灾减灾和关键决策支撑。     

大理岩脆-韧性转换变形实验研究

本文利用两组大理岩岩样进行脆-韧性变形有实验，一组在室温条件，围压变化范围为20-400MPa；另一组围压为50MPa，温度变化范围为15-200℃。前者发生脆-韧性转换的围岩范围为50-400MPa，其中变形最敏感的围压为50-150MPa，脆-韧性转换过程表现为应变硬化作用；后者发生脆-韧性转换的温度为50-200℃，其中变形最敏感的温度为100℃左右，脆-韧性转换过程表现为应变软化作用为主。在变形（实验）岩样宏观变形行为和微观构造特征分析的基础上，讨论了岩石脆-韧性转换变形的若干标志（包括力学性质、宏观变形行为和显微构造标志等），并阐明了大理岩脆-韧性转换变形方式是以微破裂、晶内滑移和碎裂流动作用为主。这些实验研究结果对于地壳中浅层次构造变形及表层构造软弱带成因研究肯有重要意义。     

Inversion of calcite twin data,paleostress reconstruction and multiphase weak deformation in cratonic interior – Evidence from the Proterozoic Cuddapah basin,India

Paleostress orientations from mechanically twinned calcite in carbonate rocks and veins in the neighborhood of large faults were investigated to comment on the nature of weak upper crustal stresses affecting sedimentary successions within the Proterozoic Cuddapah basin, India. Application of Turner's P–B–T method and Spang's Numerical dynamic analysis on Cuddapah samples provided paleostress orientations comparable to those derived from fault-slip inversion. Results from the neighborhood of E–W faults cutting through the Paleoproterozoic Papaghni and Chitravati groups and the Neoproterozoic Kurnool Group in the western Cuddapah basin, reveal existence of multiple deformation events − (1) NE–SW σ₃ in strike-slip to extensional regime along with an additional event having NW–SE σ_3, for lower Cuddapah samples; (2) compressional/transpressional event with ESE–WNW or NNE–SSW σ₁ mainly from younger Kurnool samples.Integrating results from calcite twin data inversion, fault-slip analysis and regional geology we propose that late Mesoproterozoic crustal extension led to initial opening of the Kurnool sub-basin, subsequently influenced by weak compressional deformation. The dynamic analysis of calcite twins thus constrains the stress regimes influencing basin initiation in the southern Indian cratonic interior and subsequent basin inversion in relation to craton margin mobile belts and plausible global tectonic events in the Proterozoic.     

任意晶系中非180°取向畴的矩阵分析

利用线性变换的方法，推导出三斜晶系中绕任意方向旋转任意角度的空间点阵基矢间的变换矩阵，给出了变换矩阵在四方晶系中的表达式并分析了ZrO2中的两种取向畴。     

Phillipsite in deep-sea sediments

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盾构法隧道施工对邻近摩擦单桩影响的研究

采用对隧道洞室周边及开挖面的土体施加由盾构机引起的各种荷载的方法模拟盾构施工,通过变化隧道埋深、隧道数量及开挖顺序研究盾构法开挖隧道对邻近摩擦单桩的影响。计算结果表明,隧道与桩的水平距离不变时,隧道埋深存在一个临界值,当隧道埋深为此临界值时隧道开挖引起的桩顶沉降、桩身侧移最大;隧道埋深较小时,隧道开挖会使桩产生较小的上移;隧道与桩的水平距离缩小相同值时,隧道埋深越小,开挖引起的桩顶沉降增加量越大;双隧道开挖引起的桩顶最终沉降量大于单隧道开挖引起的桩顶最终沉降量;双隧道同时开挖引起的桩顶沉降量、桩顶最大侧移大于双隧道先后开挖引起的桩顶沉降量、桩顶最大侧移;无论是同时开挖还是先后开挖,垂直双隧道引起的桩顶沉降量明显小于平行双隧道引起的桩顶沉降量。     

连拱隧道施工过程的三维空间效应模拟与分析

采用三维有限元方法动态模拟了连拱隧道的施工过程,并分析和探讨了隧道在开挖过程中围岩变形的时空效应以及左右洞施工的相互影响。分析结果表明,对单洞施工,开挖面对围岩变形的影响范围为其前后方2.5 B（B为隧洞净宽）;考虑右洞开挖,对左洞围岩位移的影响范围分别为开挖面前方（未开挖）2 B和开挖面后方（已开挖）1 B。最后分析了拱顶最大沉降量随开挖面推进的变化和产生的位置以及右洞开挖的影响。     

数字孪生技术在小型水库管理中的应用初探

针对我国小型水坝存在的安全隐患问题,本文基于数字孪生技术提出并构建了小型水坝数字孪生动态监管云平台,论述了小型水坝数字孪生平台建设思路。首先基于物联传感设备实现雨水情、坝体安全感知,然后通过构建室内外一体化精细三维模型搭建统一时空数据底座,实现视频监控与三维模型的融合,最后基于AI技术实现入侵检测,构建小型水库动态监管云平台。数字孪生技术能够为水库大坝提供全面的实时监测信息,实现实时连接与动态交互。本文初步探讨了数字孪生技术在水库大坝管理中的应用,可为小型水坝状态感知与安全管理提供参考。