煤层陷落柱高分辨率地震探测技术   总被引：2，自引：0，他引：2  

赵丽赵育台  黄丹青 《中国煤田地质》2006,18(5):52-53,59

在华北、华东及西北地区近20多个煤田的石炭二叠系中，普遍存在着因煤系地层基底厚层灰岩古岩溶塌陷形成的煤层陷落柱，尤以山西省西山及汾河沿岸的煤田、河北省太行山中段的煤田更为普遍。煤层陷落柱发育形态分为圆锥形、筒形、斜塔形、不规则形等特点，应用高分辩地震勘探技术，根据陷落柱发育区反射波同相轴中断、扭曲、能量变弱、连续性变差、分叉合并或圈闭、产状突变等特征，可有效地探测其空间位置及形态。  相似文献   

大面积深厚杂填土地基处理技术     

刘焕存  高凤莲  许珩 《岩土工程技术》2006,20(6):307-310

通过一项具体的工程实例,论述了深厚杂填土地基的基本工程特性。介绍了一种处理深厚杂填土地基的新技术———重锤冲扩挤密灰渣土桩复合地基技术,并对施工过程的控制,以及施工效果的检测结果进行了分析,得出了对于大面积深厚杂填土地基采用此技术处理后,能够消除地基深部湿陷性,复合地基承载力可以满足200 kPa。  相似文献   

Numerical simulation of ground anchors     

Nak-Kyung Kim  Jong-Sik Park  Sung-Kyu Kim 《Computers and Geotechnics》2007,34(6):498-507

A procedure of finite-element modeling and beam-column modeling of ground anchors was proposed in this study to investigate the load transfer mechanism in ground anchors. The procedure included the modeling of soil, grout, and strand tendon and the interface modeling of soil–grout and grout–strand in ground anchors. A series of finite element analyses and beam-column analyses were performed using the proposed models on ground anchors. The numerical predictions were compared with observed measurements in a field load test. The results indicated that the numerical simulation of load transfer mechanism on ground anchors can provide reasonable predictions.  相似文献   

定向钻进技术在陷落柱治理中的应用     

葛会乾 《中国煤田地质》2007,19(A01):19-20

为治理龙庞矿陷落柱实水事故，采用螺杆钻进技术在陷落柱南缘设计施工两个定向井Z5-1及Z5—2。以Z5-1定向井为例，使用Ф117．6mm钻头，采用优质化学泥浆，钻压35～40kN，随钻钻进至480m后改为回转钻进，在稳斜钻具钻到516．45m处进行水泥浆堵漏，边堵漏边钻进，并且每钻进10m左右测斜一次，直到中靶。  相似文献   

改善钢筋混凝土短柱抗震性能的研究     

宋义平  曹万林  张建伟  王新杰  范燕飞  王志惠 《世界地震工程》2007,23(1):17-20

简要介绍了改善钢筋混凝土短柱抗震性能的若干措施。为进一步提高短柱的抗震性能，本文提出了内藏“斜向劲性核心束”矩形截面混凝土短柱，并进行了7根短柱的抗震性能试验研究，试验表明，内藏“斜向劲性核心束”矩形截面混凝土短柱比普通矩形截面短柱的抗震性能显著提高。  相似文献   

钢管高强混凝土叠合柱的抗震性能研究   总被引：11，自引：1，他引：10  

李惠  吴波  林立岩 《地震工程与工程振动》1998,18(1):45-53

通过周期性往复试验,研究了钢管高混凝土叠合柱柱的破坏形态,耗能能力、延性、承载力以及各种组成部分共同工作等内容,并与钢管高强混凝土核心柱进行了对比;随后通过计算,讨论了叠合柱中有关参数对其极限承载力和影响;最后给出了叠合柱正截面极限承载力的简化计算方法。  相似文献   

Under‐ice salinity and stable isotope distribution of Saroma‐ko Lagoon,Hokkaido, northern Japan     

Maki Morimoto  Kyoko Kawanobe  Osamu Abe  Takayoshi Kawai  Toshiyuki Kawamura  Kunio Shirasawa 《水文研究》2010,24(7):904-916

In winter, lakes and lagoons at high altitudes or high latitudes have interesting hydrological cycles that differ from those in other seasons or in other regions, because water surfaces are covered with ice. Hydrological balances of lakes and lagoons are complex dynamic systems, and to elucidate them, isotopic tracers of water have been used as effective tools along with observations of precipitation, evaporation, inflows, and outflows. Here, to understand hydrological processes during freezing periods in the brackish Saroma‐ko Lagoon, Hokkaido, northern Japan, we examined horizontal and vertical distributions of salinity and isotope compositions of lagoon water and ice in 2005 and 2006. Horizontal and vertical gradients of salinity and isotope compositions were observed from the river mouth to the sea channel, and factors determining these distributions were considered. The mixing of freshwater and seawater and a freezing effect were presumed to be factors in relationships between salinity and isotopes and in relationships between surface waters and ice just above the water. A simple box model for water balance was constructed based on these putative factors to reproduce the distributions of salinity and isotope compositions of surface waters and ice. An evaluation of the model revealed that this hydrological system is controlled primarily by horizontal advection of the epilimnion, freshwater influx, and the ice growth rate. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

Effects of frictional forces acting on sidewalls of buried box culverts     

Junsuk Kang  Frazier Parker  Young J. Kang  Chai H. Yoo 《国际地质力学数值与分析法杂志》2008,32(3):289-306

The effects of frictional forces acting on the sidewalls of buried box culverts are presented as determined with finite element method (FEM) and detailed soil modelling. The possibility of reducing earth pressure on deeply buried concrete box culverts by the imperfect trench installation (ITI) method has been contemplated during the last several decades. There have been limited research results published primarily regarding the qualitative aspect of load reduction in ITIs. It was found during the course of this study that significant frictional forces develop along the sidewalls of box culverts and adjacent sidefills in ITIs. Current American Association of State Highway and Transportation Officials provisions do not consider these frictional forces, but they cannot be neglected in ITIs, as their effect is dominant. An optimum geometry for the soft zone in ITIs is presented to maximize earth load reductions. The soil–structure interaction at the box culvert–soil interface was found to have a significant effect on total earth pressure acting on the bottom slab. Predictor equations for earth load reduction rates were formulated for ITIs incorporating the optimum soft zone geometry based on the FEM. Copyright © 2007 John Wiley & Sons, Ltd.  相似文献   

Equal strain consolidation for stone columns reinforced foundation     

Kang-He Xie  Meng-Meng Lu  Gan-Bin Liu 《国际地质力学数值与分析法杂志》2009,33(15):1721-1735

Column consolidation and deformation are considered by assuming that the quantity of water flowing through the disturbed soil zone into the column is not equal to that flowing out from the column and the difference between them is equal to the volume change of the column. In addition, three patterns of distribution of the horizontal permeability of soil in the disturbed zone are also considered to account for the disturbance effect of columns construction on the surrounding soil. These three patterns include the constant distribution pattern (Pattern I), the linear distribution pattern (Pattern II) and the parabolic distribution pattern (Pattern III). By incorporating the aforementioned characteristics into the analyses, the governing equations containing two variables (i.e. the average excess pore-water pressures within the column and within the entire foundation at any depth) for the consolidation of a composite foundation are derived. The solutions of the governing equations are then obtained using a new initial condition derived from the assumption of equal strain and the equilibrium condition. On the basis of the solutions for excess pore-water pressures, the average degree of consolidation of a composite foundation is obtained and discussed. Finally, a comparison is made of some available solutions. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

人类活动对海洋生态系统影响的空间量化评价——以莱州湾海域为例   总被引：2，自引：0，他引：2  

李延峰  宋秀贤  吴在兴  俞志明 《海洋与湖沼》2015,46(1):133-139

本文针对海域管理中难以量化人类活动对海洋生态系统影响的问题,提出人海关系空间量化模型,通过完善概念模型、构建指标体系、确定权重及标准,最终利用作用强度和位置关系量化人类活动对海洋生态系统的影响,数值在0—1之间,等分为四个影响程度,由弱到强依次为微弱、中等、强烈和极强,并将该模型和量化方法应用于莱州湾海域。研究结果表明:整个莱州湾受人类活动的综合影响均值为0.425,处于中等影响程度;其中污水排放、围填海工程及港口航运是对莱州湾生态系统影响比较强烈的人类活动;研究海域中40%受到人类活动的强烈影响,44%为中等影响,16%为微弱影响。空间量化分析显示,人类活动对莱州湾近岸海域的综合影响比邻近外海强烈,其中影响较强烈的区域出现在西南近岸海区,而影响较微弱的海区则为莱州湾北部外海。该方法空间量化结果与莱州湾实际情况相符,说明人海关系空间量化模型适合定量化评估人类活动对该海域生态系统的影响,可为"山东半岛蓝色经济区"海域管理提供技术支持。  相似文献