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ＮＴＴ研究所开发出一种在硬土质地基中,利于地球环境的泥土压工程系统,使长距离曲线顶管既有可能又经济。本系统耐磨损性高、具有良好的切削效率。在长距离顶管中新型排土机构能维持高顶管效率,降低了顶管管体土壤的摩擦阻力。长距离压送排土部分尼浆材料生成泥浆。泥浆处理设备对排出泥土一般残土处理,并构成泥土改良设备。小口径顶管在砾率高的土层和有大直径的卵石土层中历来都很困难,只有在软土质条件下,才有可能实现长距 相似文献
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ＨＢＴ－５０型混凝土泵是在消化吸收国内外混凝土泵先进技术的基础上研制成功的一种全部国产化的新机型,其性能达到国内领先水平 相似文献
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对地质勘探和矿山斜井跑车事故的种类和原因进行了分析,介绍了国内外斜井防跑车安全装置的研究现状,在对各种防跑车装置进行比较后,对小断面勘探斜井使用防跑车安全装置的前景进行了展望。 相似文献
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管道穿越黄土陡坡斜井工程稳定性分析 总被引：2，自引：0，他引：2
长输油气管道工程频遇黄土冲沟,给管线的施工和安全运营带来了困难。基于邓肯-张非线性弹性本构模型,利用数值模拟方法,对斜井开挖法穿越边坡的井周及坡体的受力变形规律进行了系统的研究和分析。结果表明,在确保斜井布设在边坡潜在的最危险滑动面以外的前提下,坡顶斜井入口越接近坡肩,斜井井周及坡体的稳定性越好。鉴于黄土斜井拱顶易出现塌落的问题,基于多工况数值模拟分析结果,结合响应面方法,构建了拱顶屈服区深度的预测公式,经验证相关性良好,可用于对斜井穿越黄土冲沟或陡坡的支护设计。 相似文献
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长输油气管道经过黄土冲沟边坡时常常采用斜井穿越的方式,采用数值强度折减法与实际地形建模结合的方法,以陕西千阳黄土冲沟边坡为例,通过对黄土力学参数的不断折减,以收敛性准则作为边坡是否产生滑动的破坏判据,根据边坡滑动时的位移等值线图确定了边坡潜在滑动面的形状及位置,确定了管线穿越斜井的初始安全设计参数;基于初步设计参数研究了管线斜井开挖过程中井周土体的位移变化规律,并对斜井开挖后黄土冲沟边坡的稳定性安全系数进行了进一步分析计算。分析结果表明,所给出的管线穿越斜井设计参数的确定方法,能在设计阶段有效避开冲沟边坡潜在滑动区,基于这种设计参数使得管道斜井施工对边坡稳定性影响很小,边坡安全系数由1.162变为1.156,变化不大。根据计算结果,对斜井支护区域也提出了合理的建议。 相似文献
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卵砾石层大断面斜井井筒支护方法现场试验研究 总被引：1，自引：0，他引：1
我国缺少在巨厚卵砾石层中采用普通施工方法掘进煤矿斜井井筒的成熟支护经验。结合伊犁一矿材料斜井和回风斜井的施工过程,设计了现场支护试验方案,对不含水和含水卵砾石层大断面斜井井筒的多种支护方法进行了试验。研究结果表明,含水与不含水卵砾石层斜井井筒相比,其支架变形量和支护难度显著变大;架棚临时支护结合钢筋混凝土永久井壁支护是不含水卵砾石层大断面斜井井筒有效的支护方法;含水卵砾石层地压显现明显,采用超前支护、架棚临时支护和钢筋混凝土永久井壁支护相结合的方法可以实现围岩稳定。由试验推断,库仑和太沙基土压力理论用于计算卵砾石层围岩压力误差显著。 相似文献
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在地質勘探过程中,由于地形、地質以及施工設备等具体条件不同,除常采用平窿、豎并以外,亦常采用斜井。我队兩年來共施工了四个斜井,其中开掘最先且规模最大的为5号斜井。当时由于技术水平低,经验缺乏,故在斜井设計与施工过程中,遇到了不少的困难与问題,但通过实际工作中的摸索,取得了一些经验教訓。现將5号斜井的设計与施工中的經驗教訓初步总結如下,供大家在实际工作中的参考。 相似文献
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该文介绍了苏丹杜维姆大桥在夏季高温条件下如何确保现浇混凝土施工的质量控制措施,通过有效控制原材料温度、设备温度及环境温度,延缓了混凝土凝结时间,确保了混凝土顺利泵送和浇筑质量。 相似文献
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鉴于传统的手工方法或CAD绘制抽水试验过程中Q=f（S）及q=f（S）曲线中出现的效率低、精度不高的问题,利用Excel的计算、图表功能．以内蒙古鄂尔多斯某井田203孔8煤至17煤抽水试验资料为例,详细阐述了图表法和数值法绘制Q=f（S）及q=f（S）曲线的具体步骤及判别啦线是否正常的方法,为野外水文地质技术人员提供了一个很好的参考范本。 相似文献
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高灵敏土中CFG桩复合地基剪切液化问题探讨 总被引：1，自引：0，他引：1
应用长螺旋钻管内泵压CFG桩施工工艺处理高灵敏度土时,常常造成桩周饱和土层剪切液化,引发串孔、缩径、断桩、地面沉降等不良工程事故。通过对郑州地区高灵敏度土的动力特性试验,分析了剪切液化诱发上述问题的作用机理,探讨了剪切液化的影响范围及其防治措施。 相似文献
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Mazda Kompani-Zare Nozar Samani Siavash Behrooz-Koohenjani 《Hydrogeology Journal》2009,17(5):1175-1187
Large diameter fully cased wells that gain water from the bottom are often dug in sandy and collapsible aquifers. They have cylindrical vertical walls lined with brick or concrete. The well bottom is partially filled with aquifer material through which the flow is vertically upward. When the vertical hydraulic gradient reaches a critical value, quicksand occurs and the well structure can be destroyed. Another difficulty encountered is drawdown in the wellbore and the drying up of the well. To overcome these problems, the flow around and beneath these wells is numerically simulated. The simulation results are used to investigate the effect of well and aquifer parameters on quicksand and drawdown. For practical purposes, the dimensionless drawdown-time and dimensionless vertical gradient-time curves are developed. It was found that the ratio of filling material thickness to well radius affects the shape of these type curves. The type curves may be used to predict the time after pumping commences when quicksand occurs and the well dries up. They are also useful to design the safe pumping rate and duration as well as the optimum well radius. These are demonstrated by analyzing the pumping test data from a case study in the arid Chah Kutah region, southern Iran. 相似文献
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混凝土地下连续墙具有施工方便、质量可靠、抗渗性好等优点，在水利水电、基坑支护、地铁等防渗工程中广泛应用，所用材料既有塑性混凝土，也有刚性混凝土。在内蒙古某露天煤矿截水帷幕工程中，针对其工程地质与水文地质特征，研发一种低强度（8~10 MPa）抗渗（P6级）混凝土作为墙体浇筑材料，该混凝土水胶比值为0.68，砂率为45%，1 m3混凝土中各原材料质量分别为:水泥180 kg，粉煤灰200 kg，膨润土20 kg，砂720 kg，石子880 kg。分析了其渗透与抗渗机理，并通过钻孔取心和围井抽水试验对其效果进行了验证。试验结果表明:混凝土墙体浇筑完整、连续，抗压强度达8.3 MPa，渗透系数达8.67×10-7 cm/s。工程实施后矿坑疏排水量显著减少，该措施为矿区水资源及矿坑周边草原植被等生态环境保护奠定了基础。 相似文献
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Hydraulic barrier function of the underground continuous concrete wall in the pit of subway station and its optimization 总被引：4，自引：0，他引：4
Jianxiu Wang Lisheng Hu Lingao Wu Yiqun Tang Yanfei Zhu Ping Yang 《Environmental Geology》2009,57(2):447-453
Subway traffic is now being developed in China on a large scale and the planning subway stations are often located in dense
district with tall building. The dewatering of confined aquifer may cause ground settlement, the cracking, deformation and
tilting of the building, and even collapse. Combing with the dewatering project of environment protection of the pit of Yishan
Road station of Shanghai subway No. 9, through the inversion of seepage parameters based on the field pumping test, the hydraulic
barrier function of the underground continuous wall is simulated. The result indicates that with the reduction of the exposed
length of the filter tube and the increase of that enclosed, the drawdown of the confined aquifer decreases. Especially with
the increase of the enclosed length of the filter tube, the drawdown outside the pit can be controlled effectively. According
to the result of the numerical simulation, the design of the continuous concrete wall of the pit for Shanghai Subway No. 9
is altered and the depth of the continuous concrete wall of the standing part and that in the end well are increased to 61
and 62 m, respectively. The monitored result of the equal drawdown pumping test indicates that the drawdown outside the pit
with a distance of 1–6 m to the wall is less than 2 m; It means that there is nearly no influence on the environment around
the pit during dewatering. 相似文献
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娄新高速公路岩溶发育特征与地基处理方案优化研究 总被引：2，自引：2，他引：0
娄底—新化高速公路岩溶发育。由于邻近煤矿采矿抽排水,地下水位急降,形成土洞和塌陷。为保证公路建设经济、安全,须对岩溶路基进行处理。通过对地基处理方案影响因素进行研究与分析,运用多目标决策模糊集理论并结合层次分析方法,优选出具有多指标因素属性和模糊特性的岩溶地基处理方案。在此基础上,从地质条件出发,并考虑加固效果、工程造价等,比较了3种岩溶地基处理方案:注浆、沉管挤密桩、强夯+双层钢筋混凝土连续板。分析结果表明:强夯+双层钢筋混凝土连续板方案最佳,模糊优化计算中,该方案对优的隶属度最高,达0.86,具有施工便捷、加固效果好、成本低等优点,总造价为仅1 350万元,分别比沉管挤密桩、注浆处理少170万和360万元。 相似文献
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Peiyue Li Hui Qian Jianhua Wu Hongwei Liu Xinsheng Lyu Hongbo Zhang 《Environmental Earth Sciences》2014,71(1):293-299
Global curve-fitting method (GCFM) is regarded as an effective approach in hydrogeological parameter estimation, as it integrates and uses pumping data and water recovery data of a transient pumping test for parameter estimation. The impacts of pumping duration on hydrogeological parameter estimation by GCFM were investigated in the present study using 2 in situ pumping tests and 24 simulated transient pumping tests. Empirical formulas for determining the optimal pumping duration were derived. The study results suggest that pumping duration will have impacts on the accuracy of hydrogeological parameter estimation. When pumping duration is longer than a certain period, relative errors of hydrogeological parameter estimation keep relatively stable within an acceptable limit. Therefore, it is unnecessary to continue the pumping for a very long time after the groundwater level has become stable. When the change rate of drawdown over time (γ) in an observation well located within a distance of 100 m to the pumping well reaches 0.134, the pumping can be stopped. If there are more than one observation wells in a pumping test, the smallest γ value should be selected to determine the optimal pumping duration. This research is meaningful in the instruction of pumping tests, and will reduce test costs greatly. 相似文献