Analysis of Concrete Damage Model in Pile Body Stress Test

Automatic pile body stress test system is used in an in-situ static loading test. It’s found that strain process line has a step-like feature. When unloading, as the rebound amount of soil is less than the amount of pile body, negative frictional resistance exists in the soil. It’s considered that concrete damage model can explain the modulus “reduced” phenomenon of calibration section’s concrete. Based on damage mechanics theory, a function of modulus of concrete and its own strain are obtained. According to actual strain of pile body, different modulus are adopted to calculate pile body stress. The in-situ test results show that this method is more reasonable.     

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.     

Stability Analysis of Multiple Long Pile Models based on the Lateral Static Load Test of Pile

A mathematical model was established by using the transfer matrix based on Winkler elastic subgrade and spring supports in Newmark method. In simplification for subgrade reaction with discrete spring supports, the unequal displacements of two ends for pile section were included in the model. Lateral displacement and cross-section angle of the pile were determined by lateral static load test and the values of parameters of multiple subgrade reaction models were calculated by computer programming. By identifying the stability of long pile in different subgrade reaction models, the change patterns of three factors were analyzed, including effective length of long pile, restrictions on pile top and extensive length on the ground.     

Behavior Analysis of Laterally Loaded Single Pile under Large Deflection

Based on the simplified elastoplastic constitutive model of soil, the calculation method for the laterally loaded single pile with large deflection was submitted. The coefficient of subgrade reaction was presumed to increase linearly with depth, which simulates the soil resistance close to ground well. The relevant program was then developed using FORTRAN language. The examples show that (1)the displacement and bending moment increase nonlinearly when the lateral load and the moment load increase. (2)The pile displacement decreases with depth. (3)The pile displacement at the point which is over ten times pile diameter from ground is so small that can be neglected. (4)The pile head condition is the key factor, which influences the distributions of pile responses along depth. (5)By improving the mechanical properties of soil around pile, the maximum lateral displacement and bending moment can be decreased efficiently. The calculation results are in good agreement with the field test results and are better than those obtained using the pre existing solutions, which shows the presented solutions are reliable.     

三连栋日光温室拱式桁架结构静力分析与结构优化

为研究三连栋日光温室的合理性和安全性,通过有限元软件ANSYS对某三连栋日光温室拱式桁架结构进行了三维空间建模,并对该结构在多种荷载组合工况下进行静力分析,探讨了计算方法和结构的优化方法。结果表明：该温室结构吊物拉杆挠度偏大,不能满足设计要求。在原结构的基础上对有竖向拉杆的优化结构进行了计算分析,计算结果与理论值较吻合,且设计安全合理。研究结果为拟建者温室建模和温室结构优化提供参考。     

Study on Critical Length of Single Pile in Lime-Soil Pile Composite Foundation

The critical length of single pile in lime-soil pile composite foundation is studied by means of FEM. At the same time, the influencing factors such as lime-soil rate, diameter of pile and means of construction are studied.     

利用表面静态法发酵生产果醋的研究进展

通过对果醋酿造工艺进行阐述,特别是利用表面静态法发酵生产果醋的加工工艺,并在此基础上提出了该法的优缺点和适用范围,为发酵生产果醋的工业生产提供参考。     

Bearing Capacity Behavior of Roll Forming Filling Screw Pile

Bearing capacity behavior of roll forming filling screw pile (screw pile for short) is investigated through numerical calculation and static load test. The influence of pile-type parameters, such as width of thread tooth and thread pitch, on the ultimate bearing capacity of crew pile is studied; furthermore, the bearing capacity behavior of screw pile and that of pile with the same diameter are compared and analyzed through static load test. The results show that the ultimate bearing capacity of screw pile is a bit higher than that of pile with the same outside diameter; width of thread tooth has a distinct effect on ultimate bearing capacity which increases with the increment of width of thread tooth. When the screw pile is tested under light load, the resistance on pile side is distributed along screw pile, and tip resistance is small, but the resistance rises considerably with load increasing. Besides, the design formula of bearing capacity of screw pile is proposed.     

A Static Liquefaction Constitutive Model for Granular Materials Based on the Micromechanical Analysis

Based on the static liquefaction of granular materials, an elastoplastic static liquefaction constitutive model was proposed in the framework of critical state soil mechanics. The yielding surface and hardening rules were obtained by integrating the contact force of the model proposed by Chang and a non-associate flow rule was adopted as well. The model has taken the state dependent dialatency law and the effect of initial density to the stress-strain relationship into consideration. The parameters of the model are simple and have certain physical meanings. The predicted results obtained by the model have a good agreement with the undrained triaxial test of Toyoura sand and sand-silt mixture.     

Analysis and Study to Static and Dynamic Characterisstics for a Digital Speed Control Valve Made in Japan

n this paper,researches of digital valves in Japan in recent years are briefly de-scribed. The operation principles and the structure of a new digital speed control valve are analysed.This new valve is made by Japanese Tokyokeiki company. Based on these investigations , theoretiealanalysis,degital simulation and experimental study are emphasized to the valve's static and dynamiccharacteristics.     

Theoretical Analysis of Static Performance of Super Span Suspension Bridge with CFRP Cable

Equilibrium equation and compatibility equation are deduced to get the cable force equation and cable displacement control equation. Then the expression of characteristic parameter λ 2 in cable force equation is deduced. Meanwhile, the influence on the increment of cable force and displacement caused by λ 2 and load ratio P is analyzed. On this basis, taking 3 000 m span suspension bridge as a calculating example, the characteristics of the increment of cable force and cable displacement under symmetrical and asymmetrical load are studied. In this case, two different conditions are considered. One takes the elastic elongation into consideration, but the other does not. At last, compared with the steel cable, the influence on the parameter in cable force equation and displacement control equation caused by span is analyzed. The influence of the static performance of suspension bridge by parameter changing is analyzed as well. The substantive characteristics of the static performance of super span CFRP suspension bridge are cleared and the superiority and characteristics of CFRP cable structure are demonstrated in theory.     

Analysis of the Static Stability of Tailings Dam under Coupled Deformation and Seepage Fields

The static stability of a tailings dam is analyzed with a finite element approach, which takes into account the effect of plastic deformation, temperature, saturation and void ratio on the properties of soil materials, the effect of water and soil interaction and the extended Mohr-Coulomb failure criterion. The concept of yield approaching degree is introduced, which is defined as the ratio of the existing equivalent stress to the yield stress taking into account the effects of different influencing factors. The response of the tailing dam subjected to the coupled saturated/unsaturated seepage and deformation is simulated, considering that the dry beach is 100-meter long and the starter dam is jammed, respectively. The important indexes such as the deformation and the phreatic surface of the dam are obtained. The distribution of the yield approaching degree in the whole dam under the given condition is obtained, which can provide not only a general stability assessment of the dam, but also important information to the decision-making for the reinforcement and maintenance of the dam.     

茄子种高压静电场生物效应试验研究

利用高压静电场对茄子种子进行选种，并通过均匀设计安排试验，进行不同昨电场强度的高压静电场处理，测定茄子种的发芽势、发芽率、根长、苗高、叶面积、干鲜重、电导率和SOD值等指标，并对结果进行了回归分析和讨论，找出处理时间和电场强度的较佳取值组合。     

Field Comparative Experimental Study on Bearing Capacity of Both Bored Pile with Branches and Plates and Column Bored Pile at the Same Site

Compared with column bored pile,the bored pile with branches and plates is a new type of piles with higher bearing capacity and lower settlement.Field comparative tests related to ultimate bearing capacity of both the bored piles with branches and plates and column bored piles at the same site in Huzhou city of province Zhejiang in China were studied through self-balanced method under static pressure.The results testify that,compared with column bored pile under the same geological conditions,the bored pile with branches and plates can obtain better economic benefit such as: increasing ultimate compressive bearing capacity and ultimate extraction bearing capacity used per cubic meter concrete over 75.3%and 118.9%respectively,while dropping consumption of reinforced concrete upwards of 41.9%and 44.1% respectively,reducing settlement and pile length under the same loading.The tests will present an objective reference to the new type of piles in both theoretic study and application to analogous engineering.     

The Preliminary Study of the Automobile Steering-gear Performance Test Theory and Its Test System

This paper presents a new steering-gear performance test calculation formula,and set up a corresponding test system on this basis,and obtain a preliminary test result.     

蜱传立克次体病检测方法研究进展

为了选择更适合蜱传立克次体检测方法。通过对已发现的几种蜱传立克次体病的简单介绍,并且对目前该病检测方法的概述、分类、优缺点对比。从而为发展新的检测方法提供思路,并对未来的研究方向做了展望。     

静态顶空气相色谱法快速测定葡萄中乙醇和乙醛含量的研究

介绍了建立静态顶空气相色谱法测定贮藏后玫瑰香葡萄中乙醇、乙醛含量的方法。对顶空进样条件进行了优化,顶空温度65℃,恒温加热时间为35min最优。此方法的乙醇、乙醛检测限分别达到0.02mg/kg和0.03mg/kg,其回收率分别为98.7%和95.6%,与其它测定方法相比具有操作简单,分析快速,结果准确等优点。     

啤酒中有害微生物的检测与防治研究

啤酒中的有害微生物对啤酒的品质有很大的影响。在啤酒生产中,对有害菌的快速检验和有效控制有着重要的意义。综述了啤酒中有害微生物的检测技术和防治措施。