Dynamic Response Analysis of High-rise Pile Cap-soil-structure under the Wave and Earthquake Action

Finite element software was used to simulate the internal force and deformation of high-rise pile cap-soil-structure under the wave and earthquake action. Meanwhile, wave force was calculated by using Morison equation, and the mechanical behavior of structure was simulated by inputing horizontal El-Centro wave. Then, the initial state and the state of the largest positive and negative acceleration were selected to study the structure according to the time history curve, and the displacement, bending moment, shear and axial force changes of pile foundation under wave and earthquake action were discussed, which was compared and analyzed with the structural response under the action of earthquakes solely. The result shows that the moment of front row of piles is biggest, and the force of pile bolck is the most dangerous; the axial force of the corner piles is the largest, and one of the center piles is the smallest under the action of wave and earthquake. When the wave forces and seismic forces are in the same direction, the displacement, moment, and shear force of pile bolck will be increased, on the contrary, the displacement, moment, and shear force of pile bolck will be decreased.     

Increase of Wave Velocity in Precast Pile along with Time and Its Analysis

Low strain dynamic testing on actual pile was conducted to investigate if the wave velocity is varied in the installed pre-cast pile.It was found that the wave velocity of the pile is raised along with time.The analysis has been carried out through with one dimension and three dimension stress wave propagation theories.Among various factors influencing the rise of wave velocity,the factor of the side soil contribution is the chief one.The soil around the pile works jointly with the pile,as if to enlarge the section size of the pile.Both the increase of wave velocity and the bearing capacity of pile are consistent.So the time effect of wave velocity can be used to study the time effect of bearing capacity of the pile and to determine the bearing capacity of piles.     

Experimental Analysis on the Longitudinal Shear Resistance of Flat-type Composite Slab

The shear bond behavior of the flat-type composite deck slab, Econdek65-675 is investigated primarily. Based on the Euro code 4, the relevant value, m-k, is achieved based on the test of 18 composite slab specimens. According to the thickness which is 115 mm, 150 mm and 200 mm respectively, these 18 specimens were divided into three groups with two sets in each group. One set was tested for shorter shear span loading and the other one was set for longer shear span loading. It is shown that the Euro code 4 is more accurate than the American code. Meanwhile, the calculation formula of longitudinal shear resistance of the composite slab as well as its relevant curve is presented. Compared with other similar composite slabs, it is proved that Econdek65-675 possesses reliable composite efficiency.     

Analysis on Longitudinal Cracks and Deflection of the Pre-stressed V-shape Slab Roof Structure

In this paper, the finite element method is used to analyze the behavior of the prestressed V-shape Slab Roof structure, especially the effect of temperature change on the stress of slab. The calculated results indicate that when the temperature changes, the tensile stress at the lower extreme fibers of the flange plate near rib exceeds the tensile strength of concrete subjected to the combined action of triaxial stresses and results in the longitudinal cracks of the flange plate. The deflection analysis is based on the mechanical model of the prestressed V shape slab with the longitudinal cracks. The calculated results are in general agreement with the field observations.     

Numerical Analysis on Bearing Capacity of Piles Subjected to Side Loads

Besides the loading applied by the upper building, the piles are often subjected to indirect loading such as side loads. These kinds of loads would cause the pile bear additional force (negative skin friction), which may be large enough to reduce the bearing capacity and cause structural failure of a pile. By establishing the numerical model of pile soil interaction, the bearing capability of pile under side load was analyzed. The joint effect of different magnitude and the distance of the side load on the skin friction were focused. The joint effect of length of the pile and the distance of side load on the skin friction was discussed. The expression of the two combination relationship was obtained. Meanwhile, by using the least square method, the expression of total skin friction on different side load combination was achieved. And based on the statistical analysis of the dispersion coefficient, the function expression was proved to be of high precision. The results show that when k, which indicates the relative relation of side load distance s and the side load magnitude Q, increases to 32, the value of negative skin friction goes to zero. When c, indicating the relative relation between pile length L and side load distance s, increases to 0.5, the value of negative skin friction goes to zero. Beyond limit value of these two relative relationships, the bearing capability of the pile will not be affected by side loads.     

Application of Artificial Neural Network in Elastic Internal Force Analysis of Two Way Slab

In this paper, the Artificial Neural Network (ANN) is applied to the internal force analysis of structure. After introducing the model and algorithm of back-propagation network, a trained BP network of three layers is used to calculate the maximum of elastic moment of middle span of two-way slab. In order to enhance the generalized capability of network, the modified value of weight should be regarded as convergence standard and in order to accelerate the learning process without vibration, the method of adding momentum coefficient is adopted. The analysis program of BP network is carried out with the software of Matlab. The result demonstrates that application of ANN in structure analysis is feasible.     

An Equivalent Shear Displacement Method of Single Capped Pile in Layered Soil

Based on the interaction of single pile, cap and soil, the load transfer matrixes of single pile and soil were proposed to establish an equivalent shear displacement method of single capped pile in layered soil. With the compatibility of displacement at the interface between the pile and the soil, equilibrium equations of pile and soil could be derived. With the increase of the total load on the pile cap, the lateral friction at the interface of the pile and the soil becomes so large that the occurrence of the sliding takes place. While there is little sliding at the interface between the soil under cap and the soil outside of the cap because of the less lateral friction, which gives rives to less settlement of the soil outside of the cap. Eventually, the results of the finite element method, existing theoretical method and the model tests were compared with those from the analytical method and were found to be in good agreement. The increase of the ratio of length to diameter does not infinitely enlarge the overall stiffness of the single capped pile, because the pile cap would afford part of the loading all the time.     

Analysis on Effect of Traffic Loads on Landslide Stability

In the design of landslide control engineering,the effect of traffic loads has not been taken into account.The authors simplified the traffic loads as mobile dead loads and traffic dynamic load.The mobile dead load ranges from 2.34 to 6.41 kPa.The impact coefficient was chosen to denote the traffic dynamic load and ranges from 0.1 to 0.4.Using several stability analysis methods widely accepted by engineers,combining two analysis samples,by the contrast of stability tests with and without consideration of the mobile dead load or the traffic dynamic load,the authors found that when the traffic load is not taken into account,the stability coefficient of shallow layer landslide(<8m) is overrated by 4.3-11 percent or 5.8-12.1 percent in comparison with the case when the mobile dead load or traffic dynamic is taken into account respectively,that is,the influence of mobile dead loads and traffic dynamic load is cannot be neglected.In case of medium deep layer landslide or the road is passing through the anti sliding section,the influence of the traffic load is a little and can be neglected.     

Effects of Wave Speed on Frequencies of the Self excited Oscillation Pulsed Abrasive Water Jets

The effects of cavitation and abrasive acceleration in the self excited oscillation pulsed abrasive water jets are directly determined by its oscillating frequencies, so the wave speed in the jets and its effects on pulsed frequencies are discussed. The numerical results show that the oscillating frequencies of the jets increase obviously with decreasing wave speed, and the abrasive parameters have almost no effects on the wave speed, whereas the exit of air in fluid has significant consequences on the wave speed.It was found that these conclusions were applicable for design the nozzle of the jets.     

响应面法优化超声波提取苜蓿多糖最佳工艺条件的研究

为了更有效地提取苜蓿多糖,利用响应面法优化确立提取苜蓿多糖的最佳工艺条件。试验用超声波辅助法水提苜蓿多糖,采用RSA中的Plackett-burman设计,筛选试验因素,得出了最佳提取条件:超声波提取时间为16.69min,料液比为1∶37.4,提取温度为74.5℃,最佳得率为6.19%。该提取工艺产率稳定且效率高于普通水提法。     

Analysis of the Kinetic Theory of Submerged Abrasive Water Jets

Abrasive water jets can incise objects with strong rigidity under water. The analytical means of kinetic theory is optimal for theoretical problems of submerged abrasive water jets. The flow characteristics in submerged abrasive water jets were analyzed based on kinetic theory for multiphase flows. The impact characteristics of every phase in submerged abrasive water jets was analyzed and continuity and momentum equations subsequently were developed for solid, gas and liquids in submerged abrasive water jets. It is shown that if the distributing function of every phase were given, the law of its movement could be ascertained.     

超声波法提取胸腺肽的各影响因素分析

为了确定超声波法提取胸腺肽的最适工艺参数,以浸提液种类、超声波处理时间、浸提液料液比、浸提液pH值、离心转速,以及超声波输出功率为实验内容,进行各因素的影响作用分析。采用SAS8.2实验设计及统计分析,对参数进行单因素方差分析与多重比较,得到了最适工艺的参数范围。     

2014年春季内蒙古2次大风降雪寒潮过程分析

对于环流特征相似的寒潮过程,其爆发的方式、产生的天气和影响的区域基本相似,但个别寒潮过程却存在较大的差异,造成预报上的误判。针对此类特例,基于常规气象观测资料,自动站观测资料和NCEP逐6 h 1°×1°再分析资料,应用天气学分析和诊断方法,对2014年4月24日（过程1）和5月1日（过程2）2次寒潮天气过程的环流、系统和爆发的动力、热力学机制等进行对比分析。结果表明：2次过程北半球中高纬500 hPa环流形势均具有两脊一槽的环流特征。寒潮区域升温明显,前期平均温度分别比历史同期偏高1.0~7.3℃和0.1~10.7℃,500 hPa冷槽和强锋区均在新疆北部堆积、爆发南侵;2次过程在爆发方式和成因上存在着较大的差异,过程1中促使寒潮爆发流场为横槽转竖,槽前疏散结构和正涡度平流使低槽切断出低涡并东南移,冷平流中心移至槽前,横槽转竖寒潮爆发。过程2为低槽东移,冷槽移过阿尔泰山和蒙古高原加深东移,冷空气入侵内蒙古,寒潮爆发。虽然2次过程均造成了全区范围的强降温,但由于上述影响方式和成因的不同,使得大风、沙尘暴和降水呈现出不同的影响特点。寒潮过程中大风和沙尘暴的分布除与冷平流有关外,还与高空动量下传的地点和时间密切相关,对于寒潮过程中的降水而言,低层的温度层结及其水汽输送特点,决定了不同地区的相态变化和降水的量级。通过关注环流相似寒潮过程中的爆发方式和动力过程,对于正确预报寒潮天气造成的不同地区的降温、大风、沙尘和降水具有很好的借鉴意义。     

近66a重庆北碚高温热浪变化特征及其对花木生长的影响

为深入了解北碚区高温热浪的变化特征及其对花木生长的影响,利用重庆北碚区1951—2016年逐日平均最高气温、极端最高气温地面气象观测资料,综合采用线性回归、数理统计等方法分析分析北碚高温热浪日数、频次、强度的变化特征。结果显示,北碚高温日数、高温热浪及高温累积有效积温年际变化幅度大,在整个波动中呈现上升趋势;平均每年有32.5天的≥35℃高温日数,年均高温热浪次数为3.8次,年平均持续时间为24.7天;高温热浪引发的伏旱灾害频繁发生,在伏旱期间,当一侯中有3d极端最高温度>35.0℃时,高温伏旱开始影响花木的正常生长,当一侯中有3d极端最高温度>40.0℃时,高温伏旱对花木的生长造成严重影响。     

吉林省雪水沉积物的理化特性分析

为了研究雪水中沉积物对土壤生态环境的影响,笔者采用X射线衍射法、化学分析对吉林省长春市、白城市、延吉市雪水中沉积物的颗粒组成、矿物组成、可溶性离子组成及有机碳含量进行测定。结果表明：降雪雪水中沉积物主要以<2 μm粒径为主,平均含量大小顺序为（<2 μm）>（>200 μm）>（20~200 μm）>（2~20 μm）。雪水沉积物中原生矿物主要以石英、长石为主,黏粒矿物以蒙脱石、伊利石、高岭石、蛭石为主。大气降雪中（SO42-+NO3-）/(Ca2++NH4+)=1.38,具有对酸的较强中和能力,不易发生酸性降水,对环境酸化不造成影响。降雪沉积物中有机碳含量较高,均值为52.85 g/kg。     

超声波提取芦笋中多糖的工艺研究

探索微波辅助法提取芦笋总多糖的最佳工艺,为深入研究芦笋多糖提供技术支持。采用单因素实验和3因素3水平正交试验,采用微波辅助下的水提醇沉法提取水溶性粗多糖,经真空干燥后测定粗多糖得率,以评定多糖的提取工艺。结果显示,提取芦笋粗多糖的最佳工艺条件是:料液比为1∶40,温度为80℃,时间为30min。该条件下的粗多糖得率为3.012%。     

超声波法从小浆果树莓中提取果胶的研究

以小浆果树莓果实为原料,采用咔唑比色的方法,利用超声波法研究了超声波提取时间、超声功率和料液比对果胶提取量的影响,在此基础上进行L9(33)正交试验,确定了超声波法提取树莓果实中果胶的最佳提取条件为:料液比为1∶80,超声功率为400 W,超声波提取时间35 min,果胶含量可达1.21%。     

Study on the Travelling Wave Solutions of the KdV Burgers Equation

With the aid of the Lax Niouver transformation,the exact travelling wave solutions and the asymptotic travelling wave solutions of the KdV Burgers Equation are obtained.Furthermore,the series solutions are constructed with the Adomian integration.The relations of the travelling wave solutions between the KdV Burgers equation and the RLW Burgers equation are found.Moreover,a class of known exact solutions of the KdV Burgers equation are analysed.