Numerical Study on Neck Injury Under Different Postures in Vehicle Side Impact

Neck injury is a severe problem in traffic accidents. While most studies are focused on the neck injury in rear and front impacts, few are conducted in side impact. This study focuses on the difference of neck injury under different postures and the difference of 7 cervical vertebras under the same posture using the method of prescribed structure motion(PSM). The analytical results show that the maximum changes of mean force and mean moment of 7 cervical vertebras under 8 different postures are 20% and 47% respectively. The variation of each cervical vertebra is different under different neck postures. Up cervical vertebras (C1-C4) and low cervical vertebras (C5-C7) suffer different forces and moments under the same neck posture. Generally speaking, No.6 (neck right leaning 40°) is the posture with lowest neck injury risk.     

Discrete element approach for mine dump stability analysis

Mine overburden dumps have posed significant safety issues in the operations of various unit operations of open pit min-ing especially the external dumps. The external dumps are composed of a mixture of fragmented rocks and loose soil. Their charac-teristic is comparable to heavily discontinuous solid mass. The conventional approach of limit equilibrium methods provide safety factors for the slope but nothing about the stress-strain characteristics of the large dump mass. The designs of dump location and their respective geometry are integrated for the know-how of the stability characteristics of these dumps. The discrete element method uses a circular disk to represent the granular solid mass and their interactions are described by the Newton's third law of motion. The displacement is described by the sliding of the circular disk. This work is focused on the modeling efficiency of the discrete element methods to represent the behaviour of mine dump masses with the specified joint plane for the limit equilibrium method. The advantage of the work lies on the ease of information retrieval at any point at the dump mass concerning the stress and strain histories, displacement, failures etc. which when integrated produces a better understanding of the stability of the dump masses.     

Monitoring slope deformation using a 3-D laser image scanning system:a case study

An ILRIS-36D 3-D laser image scanning system was used to monitor the Anjialing strip mine slope on Pingshuo in Shanxi province.The basic working principles,performance indexes,features and data collection and processing methods are illustrated.The point cloud results are analyzed in detail.The rescale range analysis method was used to analyze the deformation characteristics of the slope.The results show that the trend of slope displacement is stable and that the degree of landslide danger is low.This work indicates that 3-D laser image scanning can supply multi-parameter,high precision real time data over long distances.These data can be used to study the distortion of the slope quickly and accurately.     

某反倾向岩质边坡地震稳定性数值模拟

以雅泸高速公路K136＋150～K136＋300 m段反倾向岩质边坡为例,采用基于离散元法原理的计算软件——UDEC,在充分研究边坡工程地质条件的基础上,模拟研究了反倾向岩质边坡在地震作用下的变形破坏机制及失稳破坏模式,进而分析了边坡的稳定性。结果表明：边坡在地震作用下其变形破坏是＂岩体松动→倾倒→崩塌＂的过程,此过程经历的时间较短,往往是在振动持时内完成。     

Similarity identification method on formational interfaces and application in general granite

An instrumented drilling system can be applied for the acquisition of drilling process parameters.The system can provide continuous and huge data for geotechnical engineering.However, due to the complexity of ground strata, the variation in the drilling parameters with stratigraphical characteristics is great and the correlation between likely comparable parameters is not high, which limits the use of conventional correlation approaches in this field.How to use the data for engineering and how to get a reasonable interpretation for the relationships among the drilling parameters, as well as between a drilling parameter and formational character-istics, become a technical choke point for the development and application of the instrumented drilling system.Based on similarity criteria, the extraction of sample data and characteristics, the pretreatment of data and feature matching algorithms have been ana-lyzed and an approach of slope coefficient searching identification has been established.A case study was carried out for the similar-ity between the rotational speed of the drill bit, flushing pressure, and effective thrust force graphics in general weathered granite.The result shows that the similarity coefficients between the rotational speed of the drill bit, flushing pressure, and effective thrust force are 0.72 and 0.83, respectively.Although there are differences between the distances of the graphics, the curves of both rota- tional speed and flushing pressure agree with the effective thrust curve in shape, which provides a possible method for the identifica- tion of various formations by use of the similarity between feature drilling parameters.     

一种多元复合地基复合模量的计算方法

多元复合地基的沉降计算依赖于其复合模量的取值.目前多元复合地基复合模量计算均未考虑桩对桩间土的侧向挤密作用,因而其沉降计算结果与实际值相差较大.而考虑桩体与桩间土的侧向挤压作用,依据线弹性变形理论,推求的多元复合地基的复合模量公式应用于工程实例,结果表明,该方法是合理可行的,并且存在着参数易于确定、方法简便、机理清楚的特点.     

强度折减法在高边坡支护稳定性分析中的应用

以一实际的岩土高边坡为例,探讨强度折减法的理论计算方法.利用强度折减法分别计算高边坡天然状态、未支护与支护状态下的整体稳定性,得到高边坡的整体安全系数与潜在滑动面,评价高边坡的支护系统的有效性,验证强度折减法在岩土体工程中的有效性.     

边坡爆破振动传播规律的试验研究

从爆破地震效应分析入手,对实验室内混凝土边坡的爆破振动进行试验研究,探讨爆破振动在边坡中的传播规律,并分析了边坡爆破振动对边坡作用机理和地震强度的影响。结果表明,人工预留的预裂缝作为减震沟有明显的减震效果,且表明可运用于实际的边坡爆破工程。     

友谊水库除险加固后对大坝渗透坡降的核算

针对水库"大坝左右坝肩帷幕灌浆及溢洪道固结灌浆、帷幕灌浆"施工项目完工后的实时监测,密切观测坝基渗流.通过观测对大坝进行坝基渗透坡降核算、坝体实测渗透坡降核算,坝基渗透压力基本稳定,坝基、坝体水力坡降均在允许范围内,运行良好,也说明除险加固效果达到设计水平,坝体除险加固效果达到设计要求.     

伊陕斜坡气田压裂施工中泵压异常的技术对策

通过对鄂尔多斯盆地伊陕斜坡气田压裂施工中在工作液、设备配合正常的情况下出现泵压异常升高的原因分析,采用降低施工泵压的工艺技术对策,解决了该区块压裂施工中泵压异常升高而发生砂堵的难题,确保了现场压裂施工的顺利进行,达到了对气层改造的目的。