HDD铺管引起地表工后变形的数值模拟分析     

刘耀东  石朋飞  乌效鸣 《岩土钻凿工程》2012,(4):1-5

水平定向钻进（HDD）是一种重要的非开挖铺管技术,在非开挖领域应用非常广泛。由于其会扰动周围地层以及造成地层损失,进而造成一定程度的地表变形,如地表沉降、地表水平变形等。本文采用有限差分数值模拟方法,运用FLAC3D软件分析了HDD铺管的引起的地表工后变形问题;综合考虑了不同地层内聚力、地表荷载及扩孔级数情况下的地表工后变形。  相似文献   

Changing of the guards: Detrital zircon provenance tracking sedimentological reorganization of a post-Gondwanan rift margin     

Milo Barham  Christopher L. Kirkland 《Basin Research》2020,32(5):854-874

Understanding the development of sedimentary systems during continental rifting is important for tracking environmental change and lithospheric processes. Conceptual models have been developed for the sourcing, routing and facies architecture of sediments in rift-settings, driven in part by quantitative sediment tracking. Here, we present laser ablation split-stream detrital zircon U/Pb geochronology and Hf-isotopes for post-rift (Cretaceous-Paleogene) clastic sediments from Ocean Drilling Program (ODP) wells and Plio-Pleistocene palaeoshoreline material, from the southern margin of Australia. Provenance results are contextualized through comparison with well-characterized source regions and regional pre- and syn-rift sediment reservoirs to track changes associated with Australia-Antarctica separation during East Gondwana break-up. The provenance character of the post-rift sediments studied are distinct from pre-existing sediment reservoirs and demonstrate termination of previously stable sediment routing systems and a dominance of local basement of the Proterozoic Madura and Coompana provinces (~1.2 Ga and CHUR-like Hf-signatures; Moodini Supersuite) in offshore ODP wells. A composite post-rift Cretaceous?-Eocene sample in the easternmost well expresses characteristic Phanerozoic zircon age signatures associated with source regions in eastern Australia that are interpreted to reflect inversion in the Ceduna Sub-basin to the east. Detrital zircon signatures in Plio-Pleistocene palaeoshoreline sediment are also relatively distinct, indicating derivation from coastal erosion in the Leeuwin Complex (~0.5 and 0.7 Ga subchondritic grains) and Albany–Fraser Orogen (~1.2 Ga subchondritic grains) several hundred, to over a thousand kilometers to the west. Collectively, results highlight the fundamental geological processes associated with rifting that dramatically change the character of sediment provenance via (a) isolation of pre-existing primary and secondary sources of detritus, (b) development of new source regions in basin compartmentalized highs and localized fault scarps, and (c) establishment of marine and coastal currents that redefine clastic sediment transport.  相似文献   

地应力钻孔施工关键技术探讨   总被引：1，自引：0，他引：1  

秦俊生  谭成轩  刘春生 《城市地质》2016,(4):54-58

汶川地震后,地应力研究受到重视,应力孔施工也日渐增多。本文依据多个项目实践经验,总结了地应力钻孔施工中的一些主要技术问题,介绍了钻孔结构设计按照终孔直径选择、监测仪器安装以及地层条件来综合考虑的方法。特别是从保证技术套管的使用和起拔安全,保障仪器安装精度的扩孔技术,冲洗液的选择与控制,应力测量与应力监测仪器安装的技术保障措施等应力孔施工关键技术方法方面探讨和总结了该类型钻孔施工技术特点和技术经验,系统总结了孔内应力测量和监测仪器安装技术方法,对同类项目的开展具有一定的借鉴和现实指导意义。  相似文献   

基于浅层地震勘探与钻孔联合地质剖面探测的苏北盆地倪湖庄-七里墩断裂研究     

刘旭东  张世民  晏云翔  李林元  计昊旻  赵俊香 《震灾防御技术》2022,17(1):11-27

浅层地震勘探与钻孔联合地质剖面探测是隐伏断层定位与活动性鉴定的基本手段,需在实际工作中不断总结完善。通过采用浅层地震勘探技术,查明了淮安市区附近隐伏断裂的基本格局,并结合钻孔联合地质剖面探测与第四纪年代学测定,确定了新发现的倪湖庄-七里墩断裂的最新活动时代及活动特征。倪湖庄-七里墩断裂为近南北走向、倾向西的高角度正断层,断层倾角72°～82°,探测断裂长度为43 km。浅层地震勘探揭示其断面具有近直立或呈S形的上下反倾特点,指示具有走滑性质。该断裂错断了北东走向淮阴-响水断裂与北西走向无锡-宿迁断裂,最新活动时代为中更新世中晚期。本次探测工作对技术方法进行了探索,并提出以下建议:针对新发现的隐伏断裂,宜采用从已知点向外逐次探测的方式,即完成上一条测线的设计、施工与解译工作后,根据探测结果布设下一条测线;基于地震时间剖面进行钻探设计时,既要考虑断层两盘反射波组延伸与变形特征,又要考虑物探解译上断点与实际上断点的埋深差异;在河流下游开展钻孔联合地质剖面探测与地层对比时,需充分考虑局部地貌条件差异与第四纪海平面对陆域地表过程的影响。  相似文献   

科学大洋钻探与天然气水合物   总被引：7，自引：0，他引：7  

吴能友  陈弘  蔡秋蓉  王宏斌 《地球科学进展》2003,18(5):753-758

天然气水合物是由水和甲烷等气体水分子组成的冰状物,主要分布于海洋陆坡区和陆地永久冻土带,是21世纪理想的替代能源。科学家已对天然气水合物的物理化学性质、产出条件、分布规律、勘查技术、开采工艺、经济评价及开采可能造成的环境影响等进行了广泛而深入的研究。大洋钻探计划（ODP）是获得深部含天然气水合物和游离气沉积物的唯一途径,已成功实施了164和 204两个以天然气水合物为主要目标的航次,分析研究了含天然气水合物沉积物的原位物理化学特性和地球物理性质,探讨了气体-水-沉积物-水合物间的相互作用机理,为气体储量计算提供了依据,对推动水合物研究作出了重大贡献。综合大洋钻探计划（IODP）的启动,将为人们深刻理解地球历史和地球系统过程（ESP）,特别是认识天然气水合物在地质过程中的作用,提供前所未有的机会。  相似文献   

Magnetostratigraphy and relative palaeointensity of late Neogene sediments at ODP Leg 167 Site 1010 off Baja California   总被引：2，自引：0，他引：2  

Akira Hayashida  Kenneth L. Verosub  Franz Heider  & Roman Leonhardt 《Geophysical Journal International》1999,139(3):829-840

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Development of northwest Pacific guyots: General results from Ocean Drilling Program legs 143 and 144   总被引：1，自引：0，他引：1  

Peter Flood 《Island Arc》1999,8(1):92-98

Results of the Ocean Drilling Program legs 143 and 144, which investigated the nature and origin of seven guyots in the northwest Pacific Ocean, document a history of prolonged volcanism (128–84 Ma), followed by subsidence, accumulation of shallow-water carbonates, emersion following a sea-level fall, then continued subsidence, and drowning. Generally, the life span of a guyot is of the order of 5–20 million years. The stratigraphic sequence in each guyot consists of 3–10 m-thick, shoaling-upward cycles, which display a 100-Ka periodicity perhaps related to sea-level fluctuations. The drilling results indicate that the demise of the shallow-water carbonate platforms is related to either a temporal (110–100 Ma) event or paleolatitude location (0–10°S) involving nutrient-rich water not conducive to production of calcium carbonate by shallow-water organisms. Following emergence and erosion, re-submergence occurred during a rise of sea-level. However, the rate of sediment accumulation was unable to keep pace with the rate of sea-level rise and the guyots drowned. Subsidence continued as the lithospheric plate cooled. The majority of guyots are now at ~ 1500 m below sea-level. Plate movements over the past 100 million years have carried the guyots from ~ 14°S to their current location in the northwest Pacific. Guyots are flat-topped submerged volcanic islands capped by thick sequences of shallow-water carbonates. The flat-top morphology is constructional, not related to wave planation as originally thought and reported in most textbooks.  相似文献   

超长护筒在循环护壁成孔中的应用     

秦艳频 《矿产与地质》1999,13(2):128-129

在易坍塌地层进行大口径灌注桩孔施工中,利用反循环钻进工艺,进行大口径灌注桩孔和排出渣土;采取超长护筒护壁的方法,这一技术措施是成功的,有效的。  相似文献   

大陆科学钻探与中国第一口科学钻选址   总被引：2，自引：0，他引：2  

张永康 《江苏地质》1998,22(4):193-198

大陆科学钻探是一项堪与航天技术媲美的浩大系统工程。它的实施具有深远的科学和经济意义。通过介绍国外大陆科学钻探的现状和成果,阐述大陆科学钻探对地球基础科学、其他自然科学研究所具有的重大促进作用,从而为开展我国第一口大陆科学钻探,缩短与国外先进水平的差距提供有益的借鉴。  相似文献   

含砂量对HDD钻井液性能影响的试验研究     

赵士鹤  陈亚洲  葛延明  孙平贺 《岩土钻凿工程》2014,(2):38-41

水平定向钻进铺管钻遇地层多为土、砂层,钻井液对成孔质量影响较大,而固相含量又直接影响钻井液的综合性能。本文通过室内试验,分析了不同含砂量条件下,钻井液的塑性粘度、表观粘度、动切力、动塑比的变化规律,认为含砂量在15％以下时,对钻井液流变性能变化不大,而当钻井液中的含砂量超过20％时,钻井液会产生系统破坏,需要进一步处理方可二次使用。  相似文献