An Integrated Method for Analyzing Load Transfer in Geosynthetic-reinforced and Pile-supported Embankment

Weizheng Liu,Shuai Qu,Hao Zhang,Zhihong Nie 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.3

The load transfer mechanism of a geosynthetic-reinforced and pile-supported embankmentis is influenced by the interactions among embankment fill, bridging layer, piles and foundation soil. In this paper, an integrated method for calculating the loads carried by the pile and subsoil is developed based on the displacement compatibility principle, which takes the soil arching effect, tensioned membrane effect and pile-soil interaction into account. In the presented method, the magnitude of shear stress due to the arching action depends on the relative displacement within the embankment fill and the elastic-perfectly plastic stress-displacement response is considered, the tension and strain in the geosynthetic are obtained using the parabolic method, and the hyperbolic model is adopted to relate the negative and positive skin friction with differential settlement between pile and surrounding soil. The proposed method of determining the stress on the pile and subsoil provides a better agreement with the field measurement comparing to the existing analytical methods. In addition, a parametric study is conducted to evaluate the effects of several factors on the load transfer behavior, such as the mobilization coefficient of shear strength, cohesion and internal friction angle of embankment fill, pile spacing, and compressive modulus of subsoil. The results indict that the cohesion plays a more important role in transferring of load from soft subsoil to rigid piles than the internal friction angle of embankment fill. Additionally, different optimal pile spacings which lead to the maximum stress concentration ratio are found for different embankment heights.

An Iterative Computing Method for Load Effect of Bidirectional Reinforced Embankment

Weizheng Liu,Kang Sun,Weihua Lu,Junhui Zhang,Yongxing Zhang,Bo Yang 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.5

Bidirectional reinforced embankment (BRE) technology, pile supporting in vertical and geosynthetic reinforcement in horizontal, has been widely adopted in engineering practice to control total and/or differential settlement. In design, the load distribution of BRE is essential for determining pile size (i.e., diameter and length), pile spacing, pile cap details (if any), and properties of geosynthetic reinforcement, et al. Several methods have been proposed in previous studies to investigate the load bearing mechanism in the BRE platform. However, resistance of foundation soil is typically neglected, which implies that the load on piles would be overestimated if the resistance of foundation soil is neglected or over weakened. The reason for this overestimation is that larger geosynthetic deflection would be expected without the reaction of foundation soil, which would cause a more significant soil arching and thus more load would be transferred to piles. To minimize this overestimation, a method for analyzing load transfer mechanism in the BRE was proposed, considering the subsoil resistance as well as the existence of neutral plane (i.e., zero skin friction). An equal settlement was assumed for soils at the embankment bottom and the foundation top. The iteration process was adopted to solve equations to determine the load shared by piles and soils. In derivation, the soil arch height in the embankment was calculated instead of being assumed in existing methods. A flow chart was developed to solve equations of the proposed method and two case histories from literatures were used to compose the rationality verification. Compared with the field measurement and numerical calculation, this study can be more effective in calculating loads shared by piles and soils in the BRE for the working condition with better pile end bearing stratum.

Research on Milk Conductivity Real-time Online Monitoring System

Weizheng Shen,Wenxiao Yu,Qingming Kong,Yu Zhang,Guanting Liu,Qi Wang 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.5

Bovine mastitis is one of the common diseases in the dairy industry, and is also caused by the loss in the dairy industry. Timely and effective detection of bovine mastitis has important significance. By monitoring the milk conductivity values and other parameters, is to automate the monitoring cow health, is the basis of the prevention of bovine mastitis infection. This design is based single-chip microcomputer processing core control sensor measurement unit, data transmission unit, display and control unit, online monitoring system to achieve real-time data collection, transmission, display and other control functions. For monitoring the conductivity values were piecewise linear model of the relationship between the conductivity and the feedback voltage power function curve model comparison with simulation experiment. Simulation results show that the conductivity measurement piecewise linear model is a better, fitter factor, the average relative error is 2.31% lower, measuring range is 0.7 ms / cm-11.7ms / cm. The error of measuring the overall system is of relative low ratio, but the accuracy is higher, and better meets the needs of real-time monitoring, for cow health management and prevention of bovine mastitis or other diseases provide effective technical means.

Design and Implementation of Livestock House Environmental Perception System Based on Wireless Sensor Networks

Weizheng Shen,Guanting Liu,Zhongbin Su,Rongyu Su,Yu Zhang 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.5

In order to monitor the six factors which is the most crucial influence on livestock production in livestock house, this paper designs a set of livestock house(LH) environmental perception system based on wireless sensor networks. This system is composed by a number of data acquisition nodes(DAN) connected by using Wireless Sensor Networks. Inside of DAN is equipped with six type of sensor which in charge of collecting Real-time environmental data in LH, including carbon dioxide sensor, ammonia gas sensor, illumination sensor, relative humidity sensor and so on. The communication mode between upper-computer and central node is GPRS, to research on remotely control environmental parameters in LH in the future. The upper-computer could treat data which is uploaded by several central nodes through some way, for example, data analysis based on established protocol, threshold judgment, etc. Then, the real-time data is stored by database. The stability and veracity of the system was verified by field tests which set technical grade monitors as control groups. Comparing with industrial-grade high precision monitoring instruments, the error of collecting data and wireless communication network is within normal error range, By SPSS, the result shows that there is no significant difference of P-Value(P>0.05) in different groups at same time.

Research on Analysis Model of Soybean Straw Component

Weizheng Shen,Jianbo Wang,Qingming Kong,Jing Guan,Jin Cui,Ziqing Liu 보안공학연구지원센터 2015 International Journal of Multimedia and Ubiquitous Vol.10 No.6

To achieve the rapid detection of soybean straw component, the key lies in establishing a quantitative analysis model with higher prediction accuracy which is rapid, stable and reliable. In order to establish the optimal Near-infrared (NIR) analysis model of cellulose and hemicellulose content in soybean straw, this paper uses NIR transmission technology by applying interval Partial Least Squares (iPLS) on the optimization of characteristic spectrum range of cellulose and hemicellulose spectrum. During the optimized characteristic spectrum range, prediction models of Partial Least Squares Regression (PLSR) and the Back Propagation Neural Network (BPNN) are built in the cellulose and hemicellulose contents respectively. The results show that the best modeling band of the Cellulose content is 5615-5731cm-1, and the optimal coefficient of determination of prediction model, PredictionR2(P-R2) reaches 0.9179266; And the best modeling band of the hemicellulose content is 5615-5731cm-1 ,the P-R2 is 0.920407. After the selection of iPLS optimal band, the quantitative analysis model of cellulose and hemicelluloses established by adopting the PLSR and BP Neural Network is more concise and has higher prediction accuracy and faster data computing speed. It also provides a theoretical basis for the optimization of characteristic spectrum range for the design of small dedicated NIR analytical instruments.

A Secure Scan Design based on Scan Scrambling by Pseudorandom Values and Circuit Itself

Weizheng Wang,Yan Peng,Zuoting Ning,Peng Liu,Shuo Cai 대한전자공학회 2021 Journal of semiconductor technology and science Vol.21 No.6

Scan-based Design-for-Testability (DfT) methodology has been employed extensively in intellectual property (IP) design to guarantee the testing efficiency. Nevertheless, it also becomes a liability for IP core security because the adversary can steal sensitive information such as secret keys by scan-based attacks. Many protection strategies have been proposed to oppose the scan-based noninvasive attacks by obfuscating the test data. Regrettably, most of these strategies incur the IP performance degradation or put forward the unacceptable resource requirement. In this paper, we propose a new secure scan design scheme, which scramble the test patterns with pseudo-random values and the test responses with selected internal nodes of the circuit. Without the knowledge of circuit design, the adversary cannot apply desired test patterns and cannot recover factual test responses. Thus, it can be prevented to deduce the sensitive information by scan attacks. Through simulation experiments and theoretical analyses, the proposed approach can guarantee the chip security with very low overhead and no impact on the testability.

A SERIES ACTIVE POWER FILTER ADOPTING CONTROL APPROACH OF DETECTING LOAD VOLTAGE

Yao Weizheng,Wang Qun,Liu Jinjun,Wang Zhaoan,Senior Member 전력전자학회 1998 ICPE(ISPE)논문집 Vol.- No.-

In this paper a new control approach of detecting load voltage is proposed. It can directly detect the ac side harmonic voltage of a voltage source load for the series APF to do dynamic compensation for harmonic voltages. In addition, the control methods of PWM inverter and its dc side voltage are discussed. According to these, a prototype of the series APF is manufactured and corresponding experiment studies are done.<br/>