Features of Tropical Volcanic Rock and Soil of Jakarta-Bandung HSR and Engineering Countermeasures

The geological features of three types of tropical volcanic rock and soil distributed along Jakarta-Bandung high-speed railway(HSR),including pozzolanic clayey soil,mud shale and deep soft soil,are studied through field and laboratory tests.The paper analyzes the mechanism and causes of engineering geological problems caused by tropical volcanic rock and soil and puts forward measures to control subgrade slope instability by rationally determining project type,making side slope stability control and strengthening waterproofing and drainage.The“zero front slope”tunneling technology at the portal,the simplified excavation method of double-side wall heading and the cross brace construction method of arch protection within the semi-open cut row pile frame in the“mountainside”eccentrically loaded soft soil stratum are adopted to control the instability of tunnel side and front slopes,foundation pits and working faces;CFG or pipe piles shall be used to reinforce soft and expansive foundation or replacement measures shall be taken,and the scheme of blind ditch+double-layer water sealing in ballastless track section shall be put forward to prevent arching deformation of foundation;the treatment measures of CFG pile,pipe pile and vacuum combined piled preloading are adopted to improve the bearing capacity of foundation in deep soft soil section and solve the problems of settlement control and uneven settlement.These engineering countermeasures have been applied during the construction of Jakarta-Bandung HSR and achieved good results.

Study on Hydrological Engineering Geological Conditions and Anti- leakage Measures

With the continuous development of economy and society, people's ability to transform society has been improved. To break the constraints of hydrological and climatic conditions, some hydrology and water conservancy projects were constructed to meet the needs of human activities. In the construction of hydrological engineering, geological conditions are first surveyed to determine whether there are significant geological structure problems, in order to enhance the stability of hydrological engineering and reduce the probability of hydrological engineering leakage.

Geological conditions and reservoir characteristics of various shales in major shalehosted regions of China

China is home to shales of three facies:Marine shale,continental shale,and marine-continental transitional shale.Different types of shale gas are associated with significantly different formation conditions and major controlling factors.This study compared the geological characteristics of various shales and analyzed the influences of different parameters on the formation and accumulation of shale gas.In general,shales in China’s several regions exhibit high total organic carbon(TOC)contents,which lays a sound material basis for shale gas generation.Marine strata generally show high degrees of thermal evolution.In contrast,continental shales manifest low degrees of thermal evolution,necessitating focusing on areas with relatively high degrees of thermal evolution in the process of shale gas surveys for these shales.The shales of the Wufeng and Silurian formations constitute the most favorable shale gas reservoirs since they exhibit the highest porosity among the three types of shales.These shales are followed by those in the Niutitang and Longtan formations.In contrast,the shales of the Doushantuo,Yanchang,and Qingshankou formations manifest low porosities.Furthermore,the shales of the Wufeng and Longmaxi formations exhibit high brittle mineral contents.Despite a low siliceous mineral content,the shales of the Doushantuo Formation feature a high carbonate mineral content,which can increase the shales’brittleness to some extent.For marine-continental transitional shales,where thin interbeds of tight sandstone with unequal thicknesses are generally found,it is recommended that fracturing combined with drainage of multiple sets of lithologic strata should be employed to enhance their shale gas production.

Surface Geophysical Methods used to Verify the Karst Geological Structure in the Built-up Area:A Case Study of Specific Engineering-Geological Conditions

This article presents a research study of complex limestone karst engineering-geological conditions in the municipality Valaskanear Banska Bystrica in Slovakia.The aim of the study is to demonstrate the impossibility of spatial identification of cave spaces using surface geophysical methods due to the specific engineering-geological conditions of a thick surface layer of anthropogenic fill containing highly heterogeneous anthropogenic material.Its maximum thickness is 3 m.Another specificific condition of the study area is its location in the built-up area,due to which the applicability of geophysical methods was limited.The article contains methodological recommendations to be used in analogous geological conditions with karst structures topped with anthropogenic fill,which complicates the identification of cave spaces.The recommended solution herein is the identification of the cave system using underground mapping of the karst and its projection onto the surface for which surface geophysical methods have been combined.

Engineering geological conditions and features of geologic hazards in Wudongde reservoir of Jinshajiang River valley

There is a great difference between the distribution and evolvement characteristics of slope geological hazard in the same geographical location and climatic conditions,taking the similar structural-genetic connection in Wudongde reservoir area of Jinshajiang River valley for example. In all engineering geological conditions,the chronologic age and attitude of strata,and the lithologic association factors control the distributions and evolvement characteristics of slope geological hazard in the studied area. The study shows that the slopes in geological evolution are in different stages. The conclusion helps to understand the types and the intensity of geological disasters.

Application of fulllength anchor support technology in a largesection roadway under complicated geological conditions

Coal roadway support is the foundation and strong guarantee of safe coal production. With the FLAC3D numerical simulation, the roadway fulllength anchor support mechanism was studied, and the full-length anchor forcetransferring mechanism and stressfield distribution formed by roadway surrounding rocks were analyzed, which will provide a scientific basis for a support technology in large-section roadways under complicated geological conditions and lay a foundation for the popularization and application of a full-length anchor support system under special geological conditions.

隧道富水断层破碎带突涌预报与工程对策研究

为解决高原隧道断层破碎带易发突泥冒顶灾害的问题,采用现场调查、地面物探、洞内地震波反射法、瞬变电磁法、超前钻孔等超前地质预报方法,推广洞内物探三维分析,对富水断层破碎带突泥灾害特征、超前地质预报综合成果和工程应对加固措施进行研究。结果表明:三维物探成果能快速精准查明富水破碎带空间形态,成果直观,有效指导风险判识和工程处置措施;对富水断层带预报应充分结合勘察期成果,宏观初判断层分布特性,洞内采用物钻结合、长短结合的方法;首次提出按照“探明破碎带规模形态,查明破碎带物质组分性状,观测地下水特征变化情况”的思路,研判突泥涌水风险;施工处置应按照“探泄结合,先固后进,回堵再泄”的总体原则有序开展。研究成果和手段可为类似突涌灾害超前地质预报和工程应对措施提供参考。

山区铁路慢行小变形地质病害特征及对策研究

研究目的:近年来,我国开通运营的多条山区铁路发生路基上拱、隧道底鼓、桥梁偏移等小变形地质病害,变形量一般在几十毫米甚至上百毫米,严重影响轨面平顺性,导致不同程度限速运行。本文通过3个典型案例分析,研究各类小变形地质病害的工程特征及变形原因,提出更符合工程实际的防控对策。研究结论:(1)路基上拱小变形地质病害多发生在深宽路堑地段,主要为卸荷回弹、膨胀蠕变耦合作用导致缓倾软质岩层持续变形,可采用“应力隔断、应变消能、结构脱离”的防控措施;(2)桥梁偏移小变形地质病害易发生在地形切割较陡的破碎岩土体组成的斜坡地带,处于滑坡酝酿期的蠕动阶段,应将蠕变体作为滑坡体,采取截排水和支挡措施提高其稳定性;(3)隧道底鼓小变形地质病害多发生在地质构造环境复杂区段,发生卸荷松弛-弯曲板裂耦合的挠曲褶皱型底鼓蠕变变形,可综合采用“降水压、调曲率、增厚度、提强度”的防控措施;(4)本研究成果可为后续山区铁路慢行小变形地质病害综合勘察与整治提供指导。

川西藏东交通廊道区域工程地质条件评价

区域工程地质条件是重大工程规划建设地质安全的重要保障。川西藏东交通廊道位于青藏高原东部,穿越世界上地形地貌和地质构造最复杂的地区,区域工程地质环境复杂。响应重大工程规划建设的地质安全需求,以川西藏东交通廊道重大线性工程沿线为研究区,在分析区域工程地质环境的基础上,选取9个地质环境因子指标,采用基于GIS的层次分析法,完成了区域工程地质条件评价,将研究区划分为工程地质条件好、较好、中等和差4个等级。结果显示,活动断裂是最不利的工程地质条件因素,其次是地形起伏度和地质灾害易发程度。工程地质条件好的地区远离活动断裂带和深切峡谷,呈块状、条带状分布于活动断裂带及深切峡谷之间。工程地质条件差的地区主要分布于活动断裂带和高山峡谷区,突出表现为距活动断裂较近,尤其是多条断裂相交或近于相交的地区。研究结果能够为川西藏东交通廊道重大工程规划建设地质安全提供科学支撑。

基于校企协作的地质工程专业学位研究生培养质量问题及建议

专业学位研究生培养已取得了较大发展,基于校企协作的专业学位研究生培养模式已经成为各高校较为成熟的一种教育方式。但随着该培养模式的实施,在对学生实践能力培养的过程中亦逐渐显露出一些问题。文章基于对某西部高校地质工程专业学位研究生校企协作培养模式实施的现状分析,指出校企协作培养模式实施中存在实践培养目标不清、双导师权责不清及实践考核标准低等问题,针对上述问题分析了其产生的原因,并给出了相关对策及建议。

天津市汉南路桥梁场地工程地质条件及土层地震反应分析

汉南路改线及配套服务区项目为天津市建设世界一流大港集疏运北部通道基础设施工程,工程沿线有北疆电厂专用线铁路桥和南堡铁路大桥。汉南路桥梁工程作为重要生命线工程,需在工程建设开始前进行场地地震安全性评价。本文综合前人在区域范围内地震活动性和地震构造研究成果,基于场地地震工程钻孔勘探与测试数据,建立了场地土层一维波动模型,完成了场地地表地震反应计算,取得主要成果:1)两个桥梁工程场地50年超越概率10%对应的地表水平加速度峰值分别为0.209g和0.213g;2)工程全线均位于地震动峰值加速度分区中的0.2g区。汉南路桥梁场地土层地震反应分析工作为后续工程建筑规划、震害预测和抗震设计提供了重要依据,对场地地震地质灾害评价具有重要意义。

辽宁新元古界桥头组砂岩地球化学特征及其沉积背景

【研究目的】辽宁新元古界桥头组的沉积时代仍未准确厘定,导致关于其沉积背景特别是古气候的讨论充满争议,利用岩石地球化学特征等方法对其沉积背景进行讨论具有重要意义。【研究方法】通过桥头组砂岩的岩石地球化学资料,分析CaO/(CaO+Fe)、Sr/Ba、V/(Ni+V)等元素比值以及CIA、ICV、C_(eanom)等参数,重建古风化气候条件、古盐度及古氧化−还原条件。【研究结果】桥头组砂岩样品的CIA值多数位于温暖潮湿区域,而ICV值则多数位于寒冷干燥区域;样品的CaO/(CaO+Fe)、Sr/Ba值绝大多数落入中咸水区域,少量在微咸水区域;砂岩样品的V/(Ni+V)和C_(eanom)值则处于还原区域,少量在氧化区域。【结论】桥头组并非沉积于南华纪,其沉积期总体为中咸水的缺氧还原环境、气候温暖潮湿。

工程勘察方法在河道综合治理工程中的应用——以南京市溧水区云鹤支河为例

本文选取南京市溧水区云鹤支河为研究对象,系统分析工程概况和所处地质环境条件,采用工程地质钻探和室内试验等勘察手段查明研究区工程地质条件,并对填土工程地质、堤基工程地质进行评价,认为工程中主要会遇到渗漏问题、液化问题、沉降变形问题及岸坡稳定性问题,为设计及施工方案提供可靠的地质依据,研究工程勘察方法在河道综合治理工程中的应用。

矿山工程地质勘查中水文地质问题的危害性探究

为了保证矿山施工能够在安全的环境下有效展开,在施工开始前要做好工程地质勘查工作,这样利于在矿山施工的前期准备阶段能够明确各项数据,可以全方位了解施工所在区域的地质情况,使矿山施工工作能够有详实的数据可以参考。在矿山工程地质勘查工作中,对施工所在区域的水文地质问题进行勘查,不仅决定了矿山工程建设是否能够顺利进行,还确定了矿山工程的使用质量能否保持稳定。因此,为了确保矿山工程项目的财产不受损害,同时保护人民群众的生命财产安全,需要重视水文地质问题的危害性。

复杂地质条件下岩土工程勘察技术的运用分析

研究了复杂地质条件下岩土工程勘察技术的运用,在明确复杂地质条件下岩土工程勘察工作特点的基础上,从工程地质测绘技术、直接勘探技术、高密度电法勘探技术、探地雷达勘探技术、浅层地震反射波勘探技术、大地电场岩性勘探技术、数字化技术等方面出发,分析了岩土工程勘察技术运用要点,以充分结合新老技术,形成更好的勘察成果。

龙溪水库坝址区工程地质条件分析与坝型比选

龙溪水库坝址区水文地质较复杂,强风化破碎岩体、岩溶及断层裂隙共存于库区。为确保岩溶地表成库后具有较高经济效益,结合坝址区工程地质勘察成果,对坝址和坝型适宜性进行详细论证分析。设计优选的坝址为第三坝址,坝型为高填充自密实混凝土重力坝,坝型地质适宜性好、枢纽布置紧凑、开挖及填筑工程量小,方案技术可行且经济,能充分利用水资源。

基于资源性与可压性的深部煤层气“甜点”预测

【目的】我国在鄂尔多斯盆地东缘获得多个大型深部煤层气藏的勘探突破,然而如何有效地将储量转化为产量并实现高效开发尚不明确。【方法】以神府南区为例,综合应用地质、测试、压裂及生产动态资料,围绕深部煤层气藏资源性和可压性,开展地质−工程“双甜点”评价研究。【结果和结论】结果表明:(1)研究区成煤相带适宜,以三角洲沉积为主,8+9号煤层厚度大、分布稳定,热演化程度介于0.7%~1.5%,生烃条件较好;孔−裂隙系统发育,储集空间优越,为煤层气的赋存提供了储集空间;煤层顶板以封盖能力较强的泥岩为主,位于地下水滞流区,使得区内煤层气具备良好的保存条件,煤层含气性好,具有游离气与吸附气共存的特征。(2)利用井震结合的地球物理技术刻画了煤层脆性、水平主应力差和煤层裂缝的分布特征,建立了深部煤层气地质−工程“双甜点”识别指标体系,划分了3类地质−工程“甜点”区:Ⅰ类“甜点”区位于东部,Ⅱ类“甜点”区位于中西部,Ⅲ类“甜点”区位于西北部。(3)针对区内煤层埋藏深、孔渗性差、割理裂隙发育等特征,提出以“高排量大规模注入+变黏滑溜水造缝携砂+高强度加砂+全尺度裂缝支撑”为核心的体积压裂技术。压后试采评价显示Ⅰ类“甜点”区投产井上产快,峰值产量8000 m^(3)/d左右,生产稳定在7000~8000 m^(3)/d。研究成果有效指导并推动了神府区块深部煤层气勘探开发有利区优选与先导试验区方案实施,对该区深部煤层气的规模建产具有积极意义。

岩溶地面塌陷成因及演化规律分析

为系统厘清岩溶地面塌陷成因及演化机制,笔者详细了解了岩溶地面塌陷的研究现状及发展趋势,总结了近年来国内外学者对岩溶地面塌陷成因及机制的研究成果,并对此进行了整理及分析。研究发现,岩溶地面塌陷有3个必要基础条件:(1)必须有发育的岩溶,地层存在可溶性岩石,特别是碳酸盐类岩石,在含有CO_(2)的流水溶蚀的影响下,加以沉积作用产生洞隙,形成发育的岩溶;(2)上覆较薄的松散岩土层,越薄的松散土层越容易发生塌陷,反之则越不易发生;(3)最重要的是地下水动力条件,在上述两个条件基础上,还需要有地下丰富的水流活动,对地层结构进行潜蚀及剥蚀。岩溶地面塌陷成因及演化机制因不同诱因、不同地质结构条件而有差别。该研究可为岩溶地区的工程建设和地质灾害防治提供理论依据和技术支撑。

污染场地环境岩土工程地质勘察中水文地质条件评估方法研究

针对污染场地背景下岩土工程地质勘察中水文地质勘察评估存在的问题,文章研究一种新的污染场地环境岩土工程地质勘察中水文地质条件评估方法。采用三维稳定流数学模型构建污染场地地下水污染物溶质运移模型,掌握污染物迁移的时间、范围和发展趋势;依据“源-径-汇”模式建立影响评估指标体系,使用熵权法计算各指标权重,通过多层次水位地质条件评估模式进行评分。实验表明:该方法可准确获取污染场地污染源的种类、范围和分布情况等,能够动态评估污染场地环境下水文地质条件,增加评估结果的科学性与准确性。

河南省新安煤田郁山井田深部煤层及工程地质特征研究

为新安煤田后期远景规划和下一阶段的勘查工作提供必要的资料,分析了河南省新安煤田郁山井田深部煤层及工程地质特征,研究得出,研究区的可采煤层为二1煤层,属大部分可采煤层,位于二叠系下统山西组下部,煤厚0.00~3.61 m,平均1.47 m,煤层结构简单,煤层的稳定程度为较稳定;研究区内构造中等,煤层顶底板较弱,对矿床开采有一定的影响,工程地质条件属中等,研究区地温梯度一般在1.33~1.99℃/(100 m),全区平均地温梯度值为1.61℃/(100 m),为地温正常区。