液动锤射流元件喷嘴临界流速预测与验证   总被引：2，自引：0，他引：2  

李国琳  彭枧明  柳鹤  赵志强 《吉林大学学报(地球科学版)》2010,40(1):159-163

应用CFD动态分析技术,对SC71B型液动锤内部流场进行了仿真分析,结果表明,其射流元件临界流速为20.305～22.565 m/s,大大低于凭经验预测的40 m/s。为检验这一理论预测结果,对SC71B型液动锤射流元件临界流速进行了实验测定,为21.83 m/s,表明理论预测结果与实测结果高度吻合,证明了基于CFD动态分析的液动锤射流元件临界流速理论预测方法的可行性;同时通过理论分析和实测获得了至今为止液动锤射流元件临界流速的最低值,可为研制油气钻井用低速射流元件驱动控制的液动锤提供重要参考。  相似文献   

提高非开挖穿孔锤适应能力的研究          下载免费PDF全文

詹军  蒋荣庆  辜华良 《探矿工程》1999,(4):40-41

通过对穿孔锤工艺工作原理的分析,指出在过硬土层采用高压水射流,在软弱土层（含水量大土层）中使用粉喷技术的措施来提高穿孔锤的适应能力。  相似文献   

Schmidt hammer and terrestrial laser scanning (TLS) used to detect single-event displacements on the Pleasant Valley fault (Nevada,USA)     

Timothy Stahl  Alexander Tye 《地球表面变化过程与地形》2020,45(2):473-483

Changes in surface roughness on carbonate fault scarps often reflect varying durations of subaerial weathering. On the Pleasant Valley fault in central Nevada, the documentation of a surface rupture in 1915, a long recurrence interval of faulting, slow weathering rate, and a relatively high (2–3 m) single-event displacement make the discrimination of the historical and penultimate slip patches unambiguous. Following from a 2018 study, we used a Schmidt hammer and terrestrial laser scanning (TLS) to further test whether these weathering patterns delineate exposed slip patches on a fault scarp. Results show that Schmidt hammer rebound value ranges (termed ΔR – the difference between minimum and maximum R-values in repeat impacts at a point), increase by ~8–10 points across the historical–penultimate event transition zone in two separate scarp transects. TLS-derived surface roughness also indicates a clear difference between the most recent and penultimate events. The average single-event displacement (SED) estimated using the Schmidt hammer and TLS is 2.85 m at two transect sites and is roughly equivalent to the visually estimated 3 m. While this fault is an ideal case where we know some of the slip history, the results demonstrate that these techniques show promise for discriminating slip patches on larger carbonate fault scarps with longer paleoearthquake histories, and could be used alongside ³⁶Cl cosmogenic exposure-age dating to improve paleoseismic records on normal faults. © 2019 John Wiley & Sons, Ltd.  相似文献   

复杂地层钻进中贯通式潜孔锤的应用及反循环钻头的改进   总被引：7，自引：0，他引：7  

王茂森殷琨  陈宝义贾林 《煤田地质与勘探》2005,33(5):79-80

针对贯通式潜孔锤在复杂地层钻进中遇到的问题,对反循环钻头进行了改进:在钻头上部增加喷射孔,使气流只有一少部分进入孔底,大部分经喷射孔直接进入内管,排至地面。生产试验证明,改进后的反循环钻头更有利于形成反循环,使用效果良好。   相似文献   

PDA高应变测桩技术在打桩监测中的应用     

李廷军 《上海国土资源》2005,(3):38-40,57

根据PDA对打桩过程中的桩身内拉压应力、锤击能量及初打极限承载力的监测,从而评价所选择的沉桩方法是否合理,场地地层情况与监测结果是否吻合,以及优化基桩持力层的选择,从而更好的为工程服务。  相似文献   

FGC-15D large-diameter DTH air hammer drilling system and its application in offshore rock-socketed pile hole drilling     

Kun YIN  Jianming PENG  Maosen WANG  Zhanjiang ZHOU 《世界地质(英文版)》2006,9(2)

In the past two decades, numerous large-diameter rock-socketed piles were constructed in China to support foundations of skyscrapers, great bridges or to retain soil in potential geological hazard areas. However, drilling large-diameter rock-socketed pile holes with conventional drilling method such as rotary drilling or cable tool drilling is time-consuming and the cost is usually very high. In order to drill large-diameter rock-socketed pile holes faster at relatively low cost, the FGC15A large-diameter DTH air hammer drilling system was developed in 1987 and was given the second-class award by Ministry of Geology and Mineral Resources in 1991. Since it was innovated the drilling system has been used in more than twenty important and tough projects on land, and wonderful results were acquired. At the same time the large-diameter DTH air hammer drilling system was improved continuously. The FGC15D is the latest version of the technique.  相似文献