机械钻孔灌注桩质量控制及常见事故分析

通过施工实践经验,介绍了机械钻孔灌注桩的施工质量控制要点,并针对施工中常见的坍孔、埋钻、卡钻、掉钻、缩孔、斜孔、钢筋笼上浮等常见事故,详细分析了其表现形式、事故成因及处理方法。     

矿山钻探施工中的孔内事故处理方式研究

为了能够减少钻探施工过程中的人力及材料损失,需要提前做好事故处理的预案,因此以对矿山钻探施工发生的孔内事故为例,对矿山钻探施工中的孔内事故进行研究。将矿山钻探施工中的孔内事故大致分为两类,分别是张性构造的断层带的填充物过多导致的钻探工具断裂事故,矿山钻探过程中孔内坍塌引发的埋钻事故。采用水力割刀工艺,可以提高钻孔事故处理的工作效率,减少人力物力损耗。     

岩溶地区冲(钻)孔桩施工常见事故防治及其对策

由于岩溶地质条件复杂性,往往会因坍孔、涌水、卡钻、埋钻、桩孔偏斜等事故,而妨碍冲钻孔桩施工进度,并带来较大损失,为此,要重视冲钻孔桩事故防治,做好勘察、监理、技术培训等工作,较好的完成冲钻孔装施工任务.本文结合岩溶地区特点,详细探讨冲(钻)孔桩施工常见事故,并提出防治性的技术措施,最后就如何提升冲(钻)孔桩施工质量,提出相应管理对策,以作借鉴.     

黑龙江宝兴沟金矿区ZK0702钻孔事故处理工艺

宝兴沟金矿区地层复杂,岩石普遍遭受强烈的风化和蚀变作用,因此在钻探施工过程中,地层孔壁易失稳,造成坍塌和掉块,钻孔护壁困难,经常出现夹钻和埋钻事故.以ZK0702钻孔施工为例,介绍该矿区施工过程中遇到的主要问题和施工难点,通过现场实践,采用打、反、扩、捞相结合的处理工艺,使用PAB无固相冲洗液保护孔壁,成功避免了钻孔事...     

地质岩心钻探施工中吸附卡钻事故处理分析

地质岩心钻探施工中吸附卡钻事故经常发生,在卡钻事故发生之后,一旦处理不当,就会导致部分钻孔被迫提前终孔,无法达到理想的地质岩心钻探施工目标。因此,本文以某地质岩心钻探施工项目ZK2562号孔为例,对该孔发生吸附卡钻事故的起因及处理方案进行了简单的分析。     

深部勘查钻探过程中跑钻事故处理案例分析

在破碎基岩地层进行深部钻探勘查过程中经常会出现各种意想不到的钻探事故,一旦事故出现对工期和成本都会造成巨大的影响,而且往往由于各种因素导致孔位的唯一性,尤其在已经基本接近闭孔的较深位置出现掉钻或者卡钻等事故时,重新开孔成本更会大幅度提高,此时,处理事故是唯一的选择,本文结合我公司实施勘查钻孔过程中出现的跑钻事故处理的成功案例进行阐述,以供同行在遇到类似事故时提供参考依据。     

竖井施工坠罐事故分析与预防

通过典型竖井施工坠罐事故案例,分析了竖井施工过程中坠罐事故产生的原因,应用事故树方法对竖井掘进坠罐事故进行了定性分析,提出了控制坠罐事故基本事件发生的途径,为竖井施工安全管理提供科学依据。     

基于层次分析法的钻井井塌卡钻事故分析研究

研究分析了钻井井塌卡钻事故的成因机理及其危害性,运用因果图分析法从影响井塌卡钻的地质因素、工艺因素、人为因素及管理因素等方面进行了定性系统分析.在此基础上结合层次分析法的数学理论,建立井塌卡钻事故模型,对井塌卡钻事故的致因因素权重进行计算确定,并进行一致性检验,判断计算结果的科学性,对所有致因因素权重进行排序比较,从而最终确定井塌卡钻的关键因素,分梯次进行预防,为现场施工和管理提供科学的决策依据.     

矿山水文地质工程钻探关键技术研究

由于矿山水文地质工程钻探施工难度较大,为此提出矿山水文地质工程钻探关键技术研究。根据工程地质特征,对钻孔、钻具、钻孔间距等钻探施工参数进行合理设计,对钻探设备进行选择;利用密度调整法对钻探施工过程中的地层压力进行预测;卡钻作为工程钻探过程中常见的孔内事故,根据不同规格绳索取心管的计算系数,计算出卡点位置,通过采取上提、下放、转动活动钻具等措施,对卡钻事故进行处理。通过以上三种技术完成了矿山水文地质工程钻探关键技术研究。     

岩芯钻探复杂孔内事故处理技术

绳索取芯钻探施工出现孔内事故虽然是一种常见的现象,但两次跑钻造成的孔内事故则是较为复杂的孔内事故,且事故的处理较为复杂,处理不好可能造成废孔,而经过正确的分析,采取合理的方案,通过分阶段采用一种组合式的方案解决了孔内事故,为类似钻探事故提供参考。     

企业环境应急体系建设

本文重点阐述如何结合生产安全事故应急预案、环保设施操作规程,建设满足应急要求的环境应急体系,并提出预案演练应注意的问题。     

危险性预先分析法在煤矿瓦斯事故中的应用

本文采用危险性预先分析法,统计出靖远煤业公司大水头煤矿东103综放工作面以往同类事故案例,分析工作面现状,辨识出瓦斯爆炸、瓦斯煤尘爆炸、瓦斯燃烧三类事故,提出相应预防措施.     

钻探深孔钻进技术与经验

胶东招平断裂带岩心钻探深孔钻进施工.对金刚石钻头与扩孔器、钻进参数、护壁材料及配方等优化选取.深孔钻进操作、孔内事故的预防与处理等方面采取一系列措施,取得了成功经验.深孔钻进的实现,为深部地质找矿提供可靠资料.     

The inference of accident liability from the accident record.

Under the assumption of unchanged liability after the occurrence of an accident, the distributions of accident liability in groups can be broken up into probable component distributions of liability for subgroups with different accident records. It is shown that the component distributions have the same form as the total distribution if the latter is of Type III. Accident records have some validity as indicators of accident liability, but relative certainty that particular persons have high accident liability can be achieved only for that small number of cases whose accident records include a large number of accidents. Quantitative examples are given. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aquatic Assessment of the Chernobyl Nuclear Accident and Its Remediation

This modeling study evaluated the aquatic environment affected by the Chernobyl nuclear accident and the effectiveness of remediation efforts. The study results indicate that radionuclide concentrations in the Pripyat and Dnieper rivers were well above the drinking water limits immediately after the Chernobyl accident but have decreased significantly in subsequent years due to flushing, burying, and decaying. Because high concentrations of 90Sr and 137Cs, the major radionuclides affecting human health through the aquatic pathways, are associated with flooding, two earthen dikes were constructed along the Pripyat River. The left-bank dike alone was successful in reducing the 90Sr concentration in the river by half. The 100-m-high, movable New Safe Confinement (NSC), which will cover the current Chernobyl Shelter, will reduce radionuclide contamination further in these rivers and nearby groundwater. If the Chernobyl Shelter should collapse before the NSC is built, the resulting peak radionuclide concentrations in the Dnieper River are expected to still remain below the drinking water limits. The radionuclide influx to groundwater through the NSC should not have any effect on concentrations in the Pripyat River.     

Management of ingested foreign bodies within the appendix: a case report with review of the literature

A case is reported of an elective appendectomy in a patient with known ingestion of a sharp foreign body. The metal drill bit was ingested unintentionally 3 months before presentation at our institution. Plain abdominal films demonstrated the foreign body in the right lower abdominal quadrant. Because the gold dental drill bit was sharp and thought to be lodged in the terminal ileum or cecum, an attempt was made to remove the object during colonoscopy. This attempt was unsuccessful because no drill bit could be detected in the colon or terminal ileum. A laparoscopic exploration was performed, and the foreign body was found to lie in the appendix, after bowel manipulation under fluoroscopic guidance and with direct laparoscopic visualization. A laparoscopic assisted appendectomy was performed. On pathologic examination the drill bit was embedded in the tip of the appendix with signs of intramucosal acute inflammation. Management and indication for surgery of foreign bodies in the appendix are discussed, and we review the related literature. This is the second reported case of a dental drill bit in the appendix causing appendicitis.     

Defensive burying and stress gastric erosions in alcohol-preferring AA and alcohol-avoiding ANA rats

The aim of this study was to investigate differences in shock-prod induced defensive burying and vulnerability to stress gastric ulcerations in two lines of rats selectively bred for alcohol-preference (AA) and alcohol-avoidance (ANA). Alcohol-na?ve animals from the AA and ANA lines were tested in the shock-prod defensive burying test and (after an interval of approximately 2 months) in a 75 min water-immersion stress ulceration-inducing procedure. The AA rats showed longer latencies (327.5 s) for burying after shock-prod compared with the ANA animals (128.0 s). Furthermore, the ANA rats developed more stomach ulcerations (12.35 mm) compared with the AA rats (1.30 mm). Animals also differed based on whether they had been tested for defensive burying or not, with the tested animals showing less ulceration development than the control group. We hypothesize that the difference between AA and ANA rats is controlled by some common biochemical mechanism. One likely candidate is the dopaminergic system, which is involved in both the motivational effects of alcohol, as well as anxiety and stomach ulceration. In addition, the alcohol-preferring strain seems to be less fearful and generally may be less sensitive to aversive stimuli, be it shock prod, the aversive properties of alcohol, or water immersion stress.     

Naloxone, preshock, and defensive burying.

Injected 64 male albino rats with naloxone hydrochloride (3 mg/kg) or saline and subjected them to preshock or no preshock prior to receiving a test shock that elicited defensive burying. Preshock was administered in a context different from, or the same as, that in which the test shock was delivered. The combination of naloxone and preshock led to more defensive burying than did saline and preshock. This was the case regardless of preshock context, a result suggesting that fear and/or analgesia may not always be critical ingredients in the preshock–naloxone interaction. The pattern of results for defensive burying was in basic agreement with that of other research on naloxone and defensive behavior, and it is suggested that the pattern represents an extension of the literature to a new species-specific defense reaction. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acute life-threatening event with rhabdomyolysis after starting on high-dose pyridoxine therapy in an infant with homocystinuria

A case of posttraumatic ischaemic stenosis is presented. The patient, a five year-old girl, was admitted to hospital with physical and radiological signs of small bowel obstruction about two weeks after sustaining blunt abdominal trauma in a car accident. At laparotomy two lesions of the distal jejunum were found. Proximal to this the small intestine was dilated. A segment of 25 cms. of small bowel including the two lesions was resected. Microscopic examination showed two ulcers with adjacent fibrosis consistent with ischaemic stenosis. The patient recovered completely after the operation. The entity of "seat belt syndrome" is presented.