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有机高分子改性土动力特性试验研究 总被引：5，自引：0，他引：5
翻浆冒泥是铁路路基主要病害之一。翻浆冒泥造成基床的软化和道碴板结引起道床整体弹性的降低,直接影响列车安全运营。实践证明用化学灌浆方法整治这种病害可取得良好效果。为评价选用有机高分子浆液对路基基床上的改性效果,模拟现场土性条件、应力条件、列车循环动力条件和排水条件,进行了室内循环动三轴试验,试验结果表明,有机高分子浆液改性土动强度显著提高,动力特性明显改善。改性效果在工程实践中得到验证。 相似文献
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在已完成的包括16个构件的等位移循环加载钢筋混凝土柱的系列试验中，通过在其中3根柱的塑性铰区沿混凝土受力方向安设位移计，较准确测定了混凝土测试标距内的平均应变在一个加载循环内的变化规律及其随周数增长的变化规律；发现了单周最大压应变随周数的增长而持续增大，单周最大名义拉应变随周数增长而持续减小的重要现象；并与柱顶水平力-水平位移滞回规律实测结果相对应，结合截面受力特征对所得单周和多周应变变化规律的成因作了分析。 相似文献
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Using live vegetation volume to analyze the effects of plot Pinus massoniana Lamb on water and soil conservation under natural rainfall events 总被引：1，自引：0，他引：1
Zhu-jun GU Xiao-xia WU Xiao-lei WANG Shao-yun PENG Hao LUO Xue-zheng SHI Dong-sheng YU 《国际泥沙研究》2013,28(4):579-587
The 3-D spatial distributions of vegetation are of great significance for water and soil conservation but are rarely concerned in literatures. The live vegetation volume （LVV） was used to relate to water/soil loss under 144 natural erosive rainfall events from 2007 to 2010 in a typical water-eroded area of southern China. Quadratic polynomial regression models were established for five pure tree （Pinus massoniana Lamb） plots between LVV and water （rtmoff）/soil conservation effects （RE/SE）. RE/SE corresponds to the ratios of runoff depth/soil loss of the pure tree plots to that of the control plot under each rainfall event. Increasing LVV exhibits descending （DS）, descending-ascending （DA）, ascending-descending （AD）, and ascending （AS） trends in the LVV-RE and LVV-SE curves. The effects of soil conservation on the plots were generally more noticeable than the effects of water conservation, and most of the RE and SE values reflected the positive effects of water and soil conservation. The effects were mainly positive under heavy rains （e.g., rainfall erosivity, R = 140 MJ mm ha-l h, maximum 30 min intensity, I30 = 16 mm h-l）, whereas the effects were mainly negative under light rains （e.g., R = 45 MJ mm ha-1 h, I30 = 8 mm h-l）. The trees＇ water/soil conservation effects notably transformed when rainfall erosivity and intensity were lower than the positive or negative effects to a certain threshold. About 50% rainfall events led to obvious transform effects when LVVs were near 0.5 or 0.6. These results are able to aid in the decision making on the forest reconstruction in water-eroded areas. 相似文献
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针对DTC-150防爆地质超前探测仪在工程应用中存在的几个问题,提出了研制新型矿井多波多分量地震反射波观测系统的必要性。通过对大量工程预测预报资料的分析,结合煤岩有效地震波频率特性等4个关键技术的研究,得出了煤岩有效地震波频率范围和观测系统的有效布设方式,研制了高速、高精度、多通道数据采集及处理系统,给出了掌子面绕射回波形成的探测盲区和巷道声波的处理方法,提出了掌子面绕射回波与直达波不重叠的条件。新型矿井多波多分量地震反射波观测系统的研制成功为矿井提供了更为准确、更长距离的超前预测预报手段,同时也为煤矿安全生产提供了有力的保证。 相似文献
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为了便于研究不同粗糙度结构面岩体在压剪荷载作用下的剪切强度、剪切变形等力学特性的变化规律，制作了3种具有不同起伏高度的大理岩规则齿形结构面，锯齿高度分别为0、1、3 mm，开展了不同法向应力下的结构面直剪试验。试验结果发现，结构面剪应力?剪切位移曲线可分为两类：滑动破坏型和峰值剪断型；结构面沿锯齿先爬坡后剪断的破坏过程可划分为4个阶段：压密闭合阶段、爬坡剪胀阶段、锯齿剪断阶段、挤压碾碎阶段；锯齿结构面剪切强度?法向应力曲线近似呈三段线的特征，建立了三线段剪切强度准则；锯齿结构面剪切刚度?法向应力曲线呈上凸型特征，提出了结构面剪切刚度模型公式；锯齿结构面法向位移?剪切位移曲线呈先剪缩后剪胀的变化特征，提出了评价剪胀特性的经验公式。 相似文献
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沁水盆地黄土塬区地表黄土覆盖厚度不均，地震波速度差异较大，对地震勘探的激发有较大的影响.针对区域地表地层特点，设计地震地质模型，分析不同激发层位地震正演记录.结合试验区现场试验，对比分析了正演模拟记录.结果表明，合理的激发层位能够有效压制干扰波，突出目的层位反射波，提高黄土塬区三维地震原始资料的品质. 相似文献
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煤矸石在排弃后粒径分布沿垂直剖面会呈现出明显的规律性,以现场煤矸石筛分级配为基础,进行了3试验级配下不同试样含水率时的风化煤矸石室内直剪试验。试验结果表明:低试样含水率时,风化煤矸石试验剪应力-剪位移曲线存在相对突出的峰值,呈明显应变软化现象;但随试样含水率的增加,风化煤矸石应力-应变关系呈现出明显的应变硬化特征。级配在不同含水条件下对风化矸石抗剪强度参数的影响存在差异,低试样含水率时粗颗粒形成的骨架对风化矸石内摩擦角有着重要影响,但随含水率增大,矸石细颗粒状态则对其起到控制性作用。各试验级配风化煤矸石内黏聚力随含水率增加差异减少试验值趋于一致,但内摩擦角的下降速率则明显存在区别,至饱和时风化煤矸石内摩擦角值下降至近零值,此时风化煤矸石试样抗剪强度主要由内黏聚力提供。 相似文献
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Analysis of the interaction and influence between urban underground tunnel and adjacent structure 总被引：1，自引：0，他引：1
The construction of underground project or the underground tunnel will influence the subsiding of adjacent building on the earth surface. One urban underground tunnel is adjacent to a high-rise building called Shuijingchengbao. By using three methods that are qualitative analysis of engineering geologic, experience analogism of adjacent similar engineering constructions and 3D finite element method (FEM), the interaction and influence between the tunnel and the adjacent structure was synthetically analyzed and evaluated. The result indicates that the structure’s building has neglectable disturbance to the displacement and stress of underground tunnel, the maximal vertical displacement of tunnel roof is only 1.15mm and the change of plastic zone is tiny. Hence, it can be justified that the building of the engineering is unlikely to influence the safety and stability of surrounding rock of the tunnel without abnormality construction and exceptional engineering-geology. It can offer a theoretical reference to the construction of the underground engineering. 相似文献
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