Based on the viewpoint of traditional modulus softening method and hyperbolic constitutive model，a formula of permanent deformation changing with time was established. Compared with results of dynamic triaxial test，it was found that the formula was impossibly used for the silty sand which was easily liquefied. On this basis，a rheological term was introduced into the stress equilibrium equation，by which the character of silty sand permanent deformation could be described properly. At the meantime，the way of calculating related parameters in the equations was also introduced. Plugging these parameters into the equilibrium equation，it showed that the numerical calculating results were highly identical with the test results. Although some problems needing for further studies，a new idea in studying the permanent strain was provided.

Several key characteristics of partial excavation methods are introduced, then the practicality of the excavation methods in weak and fractured rock are compared. The influence of the surface subsidence on tunnel construction methods is emphatically analyzed, meanwhile the construction parameters of several partial excavation methods are given. Thus some favorable recommendations are made combining on-site construction experience.

Combined with the pile foundation engineering constructed in loess slope for supporting super bridge, field experiments on two neighboring piles at the same slope region are conducted to investigate transmitted characteristics as well as distribution feature of axial force, skin friction and lateral earth pressure of both upslope side and downslope side under different vertical load cases. The test results show that load transmitting of pile foundation can be obviously classified into 3 regions. The first region covers from pile head to about the depth of three times pile diameter; within this region, the axial force developed in pile upslope side is less than corresponding position at downslope side; moreover, its decrease extent with pile depth and work efficiency of skin friction are greater than pile downslope side. The second region is within about pile depth of three times to ten times pile diameter, which shows a less axial force decrease extent with pile depth in upslope side and higher work efficiency of skin friction along downslope side at the same elevation. The third region starts from the pile depth of about ten times pile diameter and ends with pile tip. For pile body in this region, the difference of axial force and skin friction for two sides at the same elevation are insignificant;and the load from super region could be even and well-distributed transmitted downwards. For the special issue of uneven earth pressure of pile foundation installed in loess slope, certain reduction in some degree for vertical bearing capacity of pile design is conducted;and some necessary revision of the calculation formula is made. The acquired study results can provide a reference for other similar pile foundation.

基于对地震作用下黏性土中桩基与土动力相互作用机理的认识,从工程应用角度出发,采用量纲分析方法(π定理),在考虑影响桩基弯矩最广泛因素的基础上,提出了6个无量纲π式,并以此分析确定的半解析公式,它能对均质土体中的桩基(桩头固结)在地震作用下产生的最大弯矩进行较为准确地计算预测.结果表明,该结果与文献提供的设计图表相符,这可为实际桩基工程抗震设计提供参考.

When the stress monitoring is used to evaluate the highway rock slope stability,the problem to determine the variable regularity of stress and warning value appears.A case study was made of a typical slope along Guang-shaan Expressway to research the problems with the method of centrifugal model test and field test.The model test results show that the model test get the variable regularity of stress before failure,the variable curves are fitted with the power function,and the method of warning percentage is adopted to determine the warning value area.The field test results show that centrifugal model test results can be applied to evaluating the highway rock slope stability with stress monitoring;in the course of the stress monitoring,the researcher should notice the influence of the surrounding environment on slope.

The prediction,supporting and monitoring should together be taken account for the excavation of the weak surrounding rock tunnel.Taking the construction plan of Glongchan Tunnel as the example,the treatment process of the weak surrounding rock tunnel is presented,and the excavation scheme for the tunnel is analyzed.The CRD method is applied for Galongchan Tunnel due to the bad conditions of the surrounding rocks which rank to the V-type rock.In the advanced supporting method the multiple support techniques and CRD method are adopted during the process of the excavation,and the support stability is successfully solved.The deformation of the tunnel surrounding rocks can be obtained by using the fairly advanced technique,the non-contact measurement method.All the construction techniques for the soft and weak rock tunnels with large cross section are of the practical guiding significance to the design of the project.

For Ⅳ、Ⅴ、Ⅵ levels of weak rock,because of different levels,The calculated load of tunnel surrounding rock according to the relevant specification was too different.Based on surrounding rock sub-classification method of current highway tunnel,the relation between the new surrounding rock classification and the elastic p-wave velocity refining that was used by railway tunnel was built.The phenomenon of elastic p-wave velocity cross overlap was avoided when surrounding rock classification was different in railway tunnel.For Ⅲ、Ⅴ、Ⅴ、Ⅵ levels of weak rock,the further refining was done by Vp in railway tunnel,in order to calculate primary support design pressure of surrounding rock,so the oversize difference of computation load value Between adjacent classification was avoided.Combining with a subway tunneling of Qingdao,comprehensive fuzzy identifying method is used to judge Surrounding rock classification level of refinement and adjust,which is more safe and economical for design and construction.

According to the data from in-situ tests,the comparative analysis on the impact of construction technique including the positive circulation craftwork and the bored holes by churning drive to the bearing capacity of pile foundation in pile forming stage is carried out.The test results show that the bored piles by churning drive have eliminated the influence of the mud cakes by the side of the pile;the property of the pile load transmission has be improved,the skin friction of the pile is increased,and the decay rate of the axial force is increased;the maximum skin friction of the bored piles by churning drive is increased about 30%,the settlement of the maximum skin friction is about 50% of the settlement from positive circulation craftwork;the bored piles by churning drive have eliminated the influence of dregs at pile tip and the tip resistance of the pile is increased about 136%,and it is increased rapidly at the same settlement;the integrated influence of the bored piles by churning drive on the skin friction and the tip resistance can greatly increase the ultimate bearing capacity of the piles.

How to evaluate reasonably the stability of a soil slope reinforced with piles (SSRP) still is an urgent problem. At present, the three-dimensional (3D) finite element strength reduction method has been used for the soil slope stability analysis. However, to accurately determine the global instability of soil slopes is the key to implementing the strength reduction finite element method. In this paper, the 3D finite element strength reduction algorithm (FESRA), based on Hill’s model theory, is proposed to assess the stability of SSRP and study on the relationship between the safety coefficients of SSRP and the displacements of slope mass. The results show that: (1) the relationship between the safety coefficients of SSRP and the displacements of slope mass agrees with the Hill’s model; (2) the proposed method (3D FESRA based on Hill’s model theory) in this study may take into account simultaneously the pile response and slope stability, and makes the results of SSRP stability analysis reasonable and reliable, which could be used as a reference for the evaluation of stability of the same type of slope; and (3) further study should be done to confirm whether the proposed method in this study is suitable for other types of slopes.

目的 探讨促红细胞生成素(EPO)对血管性痴呆(VaD)大鼠海马CA1区胆碱乙酰转移酶(ChAT)的影响.方法 将经行为学筛选合格的Wistar大鼠随机分为假手术组(Sham组)、VaD组、EPO侧脑室注射+VaD组(E1组)和EPO腹部皮下注射+VaD组(E2组),采用永久性结扎双侧颈总动脉的方法建立VaD模型.通过免疫组织化学和RT-PCR方法检测VaD大鼠海马CA1区ChAT蛋白含量以及ChAT mRNA表达水平的变化.结果 EPO能明显改善VaD大鼠认知功能障碍,上调海马CA1区ChAT表达.结论 EPO可能通过增加VaD大鼠海马区ChAT表达改善其认知功能障碍.

Based on static load test of Xianyang Airport Overpass on Yongshou-Xianyang Expressway,the determination of vertical compressive load transmission characters of 3 test piles before and after soaking was studied and compared.The characters include the distribution characters of axial force and skin friction,the display characters of skin friction and pile tip resistance,as well as the ultimate bearing capacity.The results show that(1) collapse settlement of the loess around test piles is small,the distribution character of axial force after soaking is similar to that before soaking;(2) the maximum skin friction after soaking is smaller than that before soaking under the same load,the display character of skin friction after soaking is smaller than that before soaking,and the corresponding display character of pile tip resistance after soaking is greater than that before soaking;(3) from the pile tip resistance that accounts for percent of total load,test piles are friction pile.The determination of vertical ultimate bearing capacity shows that the vertical ultimate bearing capacity of single pile after soaking is two levels lower than that before soaking.The corresponding treatment measures were proposed.

Objective To study the personality and coping style of the aviation and research the influential factors on their mental health.Methods A total of 1341 aviation soldiers were tested by the Symptom Checklist 90(SCL-90),Eysenck Personality Questionaire(EPQ) and Simplified Coping Style Questionaire.Results The mental health status of the aviation was negatively correlated with extraversion scale(EPQ-E) and the positive coping style,positively correlated with neuroticism scale(EPQ-N) and the negative coping style,and wasn't significantly correlated with psychoticism scale(EPQ-P).Conclusion In order to improve the mental health of the aviation,it is necessary to perfect their personality and promote them to take the positive coping style.