Northwest Research Institute of Engineering Investigations and Design

Fengcheng, China

Northwest Research Institute of Engineering Investigations and Design

Fengcheng, China
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Li J.,Central South University | Li J.,Hunan Normal University | Tang J.-T.,Central South University | Xu Z.-M.,Central South University | And 2 more authors.
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2017

It is a very challenging task to carry out the high-precision signal-to-noise separation for magnetotelluric sounding data in ore concentration area. In order to avoid “over processing” of morphological filtering method in the strong interference separation, and further reserve the useful information of magnetotelluric sounding data in low frequency band, a new method of magnetotelluric noise suppression base on signal-to-noise identification is proposed in this paper. First of all, according to the different complexity of morphological characteristics between the strong interference types of ore concentration area and natural magnetotelluric signal, we combine mathematical morphology, fractal dimension and morphological spectrum, introducing the robust characteristic parameters-morphological fractal dimension and morphological spectrum entropy to quantitatively indentify magnetotelluric signal and strong interferences. Then, we combine morphological filtering technology with threshold method to suppress noise, which is not natural magnetotelluric signal but abnormal waveform by identification. Finally, we reconstruct the useful signal of magnetotelluric and evaluate algorithm performance. Simulation results show that the proposed method can be more finely reserve the slow change information in low frequency band, and the reconstructed time series of magnetotelluric are approach to the essence characteristics of natural magnetotelluric signal. When it suppresses the adjacent source interference in ore concentration area, the method can effectively avoid the “over processing” of the morphology filtering technology in the noise suppression, and the integral morphology of Cagniard resistivity-phase curve is more smooth and continuous. Moreover, the apparent resistivity values are relatively stable. The results are more truly reflect the inherent deep structure information of measured data itself, and the overall data quality of the low frequency band has been improved significantly. © 2017, Science Press. All right reserved.


Hu J.,Longdong University | Hu J.,Provincial Key Laboratory of Yellow Soil Engineering Properties and Applications | Wang J.,Northwest Research Institute of Engineering Investigations and Design | Zhang J.,Longdong University | Cheng Z.,Gansu Agricultural University
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2017

The influences of sand content on free infiltration characteristics of muddy water film hole irrigation and water content distribution in wetted soil are studied experimentally. Through indoor free infiltration of clean water film hole irrigation experiments with four different sand contents in muddy water, the relationships between free infiltrations of muddy water film hole infiltration parameters, wetting front transport parameters and wetted soil water content distribution parameters after the irrigation and the different sand contents are established. A cumulative infiltration model per unit film area, wetting front transport model, wetted soil water content distribution model and film infiltration declining feature due to the increasing sand content are put forward. It is demonstrated that with increasing muddy water sand content, the cumulative infiltration decreases and less than that of clean water under the same condition. The infiltration coefficient K decreases with increasing sand content, but the infiltration index α increases with the increasing content. In the same infiltration time, with increasing sand content, the vertical and horizontal wetting front transport distances are gradually reduced. With increasing distance from the center of film hole, the water mass content in wetted soil reduces gradually in the vertical and horizontal directions. The sand contents in muddy water can reduce film hole irrigation infiltration in comparison with clean water, particularly, the higher the sand content, the smaller the infiltration rate. © 2017, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.


Li J.,Central South University | Li J.,Hunan Normal University | Tang J.-T.,Central South University | Yan H.,Hunan Normal University | And 3 more authors.
Chinese Journal of Geophysics (Acta Geophysica Sinica) | Year: 2017

In order to analyze the essential characteristics of magnetotelluric (MT) sounding data and strong interferences, and further to separate weak useful MT signal, we propose a new method for identification and separation of MT signal and noise based on recurrence analysis and clustering. First, we use the recurrence analysis method to extend the dimension of MT time series and analyze the embedding dimension, delay time and determination threshold, and study the Recurrence Quantification Analysis (RQA) parameters for the sequence of different lengths. Then, we build a sample dataset for typical strong interferences and weak useful MT signal. According to the sample dataset, we discuss the RQA parameters between strong interferences and weak MT signal, and analyze the effects of signal and noise identification for the K-means clustering and fuzzy C-means clustering. Finally, the real MT data is processed through signal and noise identification, and only the time series containing strong interferences are suppressed by mathematical morphology filtering. Experimental results show that the recurrence analysis can qualitatively and quantitatively describe the nonlinear characteristics of the time series and the essential rule of the prime power system for MT. Combined with clustering algorithm permits to identify the measured MT data in ore concentration area. The Cagniard resistivity-phase curve is more smooth and continuous after using the proposed method. Moreover, the slow change information of low frequency for MT is more retained finely, and the quality of MT data for the overall low frequency band is improved significantly. © 2017, Science Press. All right reserved.


Li J.,Central South University | Hao K.,Northwest Research Institute of Engineering Investigations and Design | Peng F.,Tongji University
KSCE Journal of Civil Engineering | Year: 2017

Filter paper technique, humidity control technique and axis translation technique were used to study suction equilibrium time of unsaturated reticulate red clay. Test results show that: (a) suction equilibrium exists in both suction measurement or suction control using any technique in the tests; (b) suction equilibrium time of unsaturated reticulate red clay can be as short as several tens hour or several days for different suction measuring techniques, or long as several days or several tens day for different suction controlling techniques; (c) suction equilibrium time consumed in process of suction measurement is shorter than that of suction control using the same technique; (d) suction equilibrium time in measuring matric suction of unsaturated reticulate red clay using axis translation technique is shorter than that using filter paper technique; and (e) suction equilibrium time of drying process is much longer than that of wetting process, when suction is controlled using humidity control technique. © 2017 Korean Society of Civil Engineers and Springer-Verlag Berlin Heidelberg


Zhong Y.,Xi'an University of Technology | Fei L.,Xi'an University of Technology | Fu Y.,Xi'an University of Technology | Jin S.,Xi'an University of Technology | Wang J.,Northwest Research Institute of Engineering Investigations and Design
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2017

In order to reveal the difference of muddy water infiltration and clean water infiltration, through the test data of free infiltration of muddy water film hole irrigation, analyzing the influence of free water infiltration capacity of muddy water film hole irrigation, such as clay and sand grade, size of film hole, soil bulk density and initial soil water content were researched. The results show that various factors all have a significant impact on the film hole irrigation free infiltration capacity, putting forward the relationship between the influence factors and the infiltration capacity of muddy water film hole irrigation. The model of clay and sand grade, size of film hole, soil bulk density and cumulative infiltration volume per unit film hole area of free infiltration of muddy water film hole irrigation of initial soil water content and steady infiltration rate was established. Moreover its correlation coefficient is greater than 0.9600. Based on the model, the cumulative infiltration volume per unit film hole area and steady infiltration rate can be obtained, further judging the free infiltration capacity in soil under muddy water film hole irrigation. The results could provide a reference for further studies of muddy water film hole irrigation free infiltration law and technology. © 2017, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.


Wu J.,Xi'an University of Technology | Zhu D.,Xi'an University of Technology | Liu Y.,Jiangxi Provincial Research Institute of Water Resources | Tao W.,Xi'an University of Technology | Wang J.,Northwest Research Institute of Engineering Investigations and Design
Paiguan Jixie Gongcheng Xuebao/Journal of Drainage and Irrigation Machinery Engineering | Year: 2016

In order to judge the comprehensive application of irrigation district scientifically and achieve the benefit maximization, comprehensive evaluation of operational status of large-scale irrigation district is necessary. First, the Delphi and the fuzzy analysis method are combined; then the structure of entropy method is introduced based on the information entropy to evaluate the evaluation indexes; finally, the close value method is used to evaluate Luohuiqu irrigation operational status of the 2007-2012 years. The results show that the close value of the irrigation district in 2007-2012 is 2.7192, 2.2051, 1.3117, 0.4855, 0.1888, and 0, respectively, and its operational condition is getting better and better. The close value of adjacent years is 0.5142, 0.8933, 0.8263, 0.2967, and 0.1888, tending to a stable condition. The comprehensive evaluation of operational status of large-scale irrigation district based on modified close value method roughly agrees with the evaluation results with the method of grey correlation theory-TOPSOS. The operational condition is getting better and better with the passage of time and more accurate, which also accords with the actual development of Luohuiqu irrigation district. This method is simple in calculation and has high reliability. © 2016, Editorial Department of Journal of Drainage and Irrigation Machinery Engineering. All right reserved.


Fang X.,Chengdu University of Technology | Li T.,Chengdu University of Technology | Ma H.,Northwest Research Institute of Engineering Investigations and Design | Wang F.,Chengdu University of Technology
Geotechnical Special Publication | Year: 2013

The attenuation plateau formed during radiation of dynamic compaction shockwave has a severe impact on construction work in loess backfill site and safety of buildings nearby. With essential targets of finding out reasons for attenuation plateau formation and providing basis for safe distance determination, geophysical prospecting was adopted in the test for in-depth investigation on the attenuation plateau characteristics of shockwave so as to provide basic data for attenuation law study of shockwave. Appropriate cut-off frequency was selected according to the test results and energy composition characteristics of elastic wave in semi-infinite soil. The shockwave energy was divided into body wave energy and surface wave energy in order to analyze energy attenuation characteristics of different waves. It is confirmed that the main reasons for attenuation plateau formation in the area were proportion and radiation characteristics of body wave energy. On this basis, staircase method was used to fit the radiation attenuation characteristics of dynamic compaction shockwave through subsection regression and compare with traditional fitting methods. The results showed that in close-distance and high-density dynamic compaction work, staircase method can be more accurate to mark out safe distance. © 2013 American Society of Civil Engineers.


Yunjun L.,Northwest Research Institute of Engineering Investigations and Design | Qianli X.,Northwest Research Institute of Engineering Investigations and Design
Applied Mechanics and Materials | Year: 2013

Highway landslide disaster is the main type of geological hazard in China, which causes great economic loss and casualty. According to the engineering experience, discrimination and criterion of highway landslide disaster is put forward in this paper on the basis of laws and types of highway landslide disaster, which includes nine big macroscopic discriminant criterion and five big microscopic discriminant criterion. On the basis of development process and stage, the development of landslide disaster is divided into three stages according to the practical needs: early embryonic stage, medium potential stage, late induced phase. To regional discriminant criterion of highway landslide disaster as the foundation, this paper presents the discriminant criterion of development for highway landslide disaster. It is hoped that the findings herein will provide science direction for temporal discriminant of highway landslide disaster. © (2013) Trans Tech Publications, Switzerland.


Cui G.-Q.,Xi'an University of Architecture and Technology | Liu Z.-R.,Xi'an University of Architecture and Technology | Ma C.-G.,Northwest Research Institute of Engineering Investigations and Design
Applied Mechanics and Materials | Year: 2013

Structure and anisotropy are two fundamental aspects of natural clays. They can't be ignored because of their significant influences on soil's strength and stress-strain behavior, etc. Therefore, anisotropic tensor and structural parameters are introduced in Modified Cam Clay Model which is only suitable for isotropic remolded clays, and evolution laws of them are given in this paper. Thus, an elasto-plastic constitutive model considering the influences of natural soil structure and anisotropy is established. Most parameters involved in this model have explicit physical meaning and are easily determined through geotechnical tests, which makes this model more flexible, practical and applicable to practical engineering. © (2013) Trans Tech Publications, Switzerland.


Liu K.,Northwest Research Institute of Engineering Investigations and Design | Zhao H.,Northwest Research Institute of Engineering Investigations and Design
Xi'an Jianzhu Keji Daxue Xuebao/Journal of Xi'an University of Architecture and Technology | Year: 2014

In order to ensure safety of deep foundation pit nearby the subway station in the construction process, the deformation of pile-anchor retaining structure nearby the subway station in the construction process is analyzed by numerical simulation method, and its stability is also analyzed. The study showed that the maximum lateral displacement of pit-retaining structure occurs at about 7m away from the top of the pit, and maximum lateral displacement is 13.4mm And the maximum surface subsidence occurs at about 4m away from the pit, and the largest settlement is 8.81mm. the pile-anchor retaining structure has good stability, and can effectively control the deformation of the pit during excavation. This background engineering deep foundation excavation does not affect the safety of the subway station.

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