Damage distribution during the 1994 Northridge, California, earthquake relative to generalized categories of surficial geology     

M.D. Trifunac  M.I. Todorovska 《Soil Dynamics and Earthquake Engineering》1998,17(4):239-253

The spatial distributions of severely damaged buildings (red-tagged) and of breaks in the water distribution system following the 1994 Northridge, California, earthquake (M_L = 6·4) are investigated relative to the local characteristics of surficial geology. The pipe breaks are used as an indicator of nonlinear soil response, and the red-tagged buildings as indicator of severe shaking. The surficial geology is described by several generalized categories based on age, textural character and thickness of the near surface layer. Two regions are studied: the San Fernando Valley and Los Angeles-Santa Monica. The analysis shows that there is no simple correlation between damage patterns and surficial geology. Single family wood-frame buildings were damaged less when built on fine silt and clay (0–3 m thick) from the late Holocene.  相似文献   

Experimental and computational validation and verification of the Stokes–Darcy and continuum pipe flow models for karst aquifers with dual porosity structure     

Xiaolong Hu  Xiaoming Wang  Max Gunzburger  Fei Hua  Yanzhao Cao 《水文研究》2012,26(13):2031-2040

In our previous study, we developed the Stokes–Darcy (SD) model was developed for flow in a karst aquifer with a conduit bedded in matrix, and the Beavers–Joseph (BJ) condition was used to describe the matrix–conduit interface. We also studied the mathematical well‐posedness of a coupled continuum pipe flow (CCPF) model as well as convergence rates of its finite element approximation. In this study, to compare the SD model with the CCPF model, we used numerical analyses to validate finite element discretisation methods for the two models. Using computational experiments, simulation codes implementing the finite element discretisations are then verified. Further model validation studies are based on the results of laboratory experiments. Comparing the results of computer simulations and experiments, we concluded that the SD model with the Beavers–Joseph interface condition is a valid model for conduit–matrix systems. On the other hand, the CCPF model with the value of the exchange parameter chosen within the range suggested in the literature perhaps does not result in good agreement with experimental observations. We then examined the sensitivity of the CCPF model with respect to the exchange parameter, concluding that, as has previously been noted, the model is highly sensitive for small values of the exchange parameter. However, for larger values, the model becomes less sensitive and, more important, also produces results that are in better agreement with experimental observations. This suggests that the CCPF model may also produce accurate simulation results, if one chooses larger values of the exchange parameter than those suggested in the literature. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

Experimental Study on Response Performance of VIV of A Flexible Riser with Helical Strakes   总被引：1，自引：1，他引：0  

高云  付世晓  曹静  陈一帆 《海洋工程》2015,29(5):673-690

Laboratory tests were conducted on a flexible riser with and without helical strakes. The aim of the present work is to further understand the response performance of the vortex induced vibration (VIV) for a riser with helical strakes. The experiment was accomplished in the towing tank and the relative current was simulated by towing a flexible riser in one direction. Based on the modal analysis method, the displacement responses can be obtained by the measured strain. The strakes with different heights are analyzed here, and the response parameters like strain response and displacement response are studied. The experimental results show that the in-line (IL) response is as important as the cross-flow (CF) response, however, many industrial analysis methods usually ignore the IL response due to VIV. The results also indicate that the response characteristics of a bare riser can be quite distinct from that of a riser with helical strakes, and the response performance depends on the geometry on the helical strakes closely. The fatigue damage is further discussed and the results show that the fatigue damage in the CF direction is of the same order as that in the IL direction for the bare riser. However, for the riser with helical strakes, the fatigue damage in the CF direction is much smaller than that in the IL direction.  相似文献   

基于Web的地下管网溯源分析算法研究     

董万虎 《地理空间信息》2021,19(4):71-72,77

利用.NetCore的并行运算机制,实现基于Web的高性能地下管网的溯源分析功能。实践证明当某点管网数据监测出现异常时,能够快速分析所有可能流经该点源头管网信息,并在地图上动态展示分析结果,达到快速定位查询管网源头的区域管理目的。  相似文献   

超长管棚施工技术在山岭隧道软弱围岩中的应用          下载免费PDF全文

冯劲  林廷松  周红升 《探矿工程》2010,37(11):73-75

以黄衢南高速公路阳排尖隧道为例,介绍了大于30 m超长管棚施工技术;并根据现场监控量测数据,对左右洞不同管棚施工技术效果进行对比分析;分析结果显示,一次性施作超长管棚在山岭隧道软弱围岩地段有较好的实用性。  相似文献   

苏通大桥二期试桩后压浆的施工及效果检测          下载免费PDF全文

徐家明  李兆琴  方宏 《江苏地质》2010,34(1):79-83

随着高层建筑和大型桥梁的兴建,钻孔灌注桩在工程中已得到了极为广泛的应用。但是,钻孔灌注桩的固有缺陷,例如孔底沉渣、孔壁泥浆、端阻力、侧阻力发挥不同步等,限制了其承载力的发挥并且沉降较大。由此,钻孔灌注桩压力注浆技术应运而生,并被逐渐应用于工程实践中。所以,对桩的后压浆施工工艺、受力机理等技术问题进行研究是非常重要的。在国内外现有的理论研究和工程应用基础上,通过对苏通大桥Ⅱ期的试桩工程施工,详细阐述了桩端后压浆技术的具体应用。同时,利用钻孔取心及CT检测技术分析后压浆的施工效果。  相似文献   

石油钻杆接头水基淬火的研究          下载免费PDF全文

岳鹏  田连社  付源  张国杰 《探矿工程》2010,37(4):14-19

对石油钻杆接头水淬热处理技术进行了研究分析。介绍了水基淬火和油基淬火后石油钻杆接头的硬度、硬度均匀性的对比试验;不同条件下的淬火液对钻杆接头冷却速度的影响。研究表明,水基淬火方式能更好地提高钻杆接头马氏体化程度,从而提高淬火质量。  相似文献   

斜井长距离混凝土泵送技术          下载免费PDF全文

袁华俊  刘野  刘则启 《探矿工程》2010,37(4):78-81

以降云顶隧洞混凝土泵送为例,分析了斜井长距离混凝土泵送存在的问题、堵管机理及解决的方法,并论述了斜井长距离混凝土泵送设计与操作流程。  相似文献   

大唐国际东营一期49.5 MW风电场工程桩基施工及其原体试验          下载免费PDF全文

李吉林  张旭虎 《探矿工程》2010,37(9):40-45

大唐国际东营风电一期工程拟建风电场场区位于东营市东部沿海区域,拟建场地上覆第四系地层,结构松散,厚度较大,工程性质较差,地基强度较低,不能满足重要建（构）筑物对其强度及变形的要求,且场地内的饱和粉土及砂土在地震影响烈度达Ⅶ度时将可能产生液化现象,因此需进行地基处理。根据现场岩土条件,拟采用预应力高强混凝土管桩（PHC）,需进行桩基原体试验。主要介绍了桩基原体试验施工过程、检测方法及试验成果等。  相似文献   

地下连续墙技术在深基坑围护中的应用     

刘永杰  左新明  王建华 《探矿工程》2010,37(7):44-49

结合某高层建筑深基坑围护的工程实例,介绍了地下连续墙施工技术在深基坑围护工程中的具体应用,阐述了地下连续墙施工的工艺流程和技术要点,提出了施工的注意事项和特殊问题的预防处理方法。  相似文献