Han K.,Northwest Research Institute Co. of C.R.E.C |
Ma H.-M.,China Academy of Railway Sciences |
Si X.-D.,Shandong Zhengyuan Construction Engineering Co.
Journal of Railway Engineering Society | Year: 2016
Research purposes: A large number of mountainous highways under constuction and that is already built involve cutting slope engineering problems. Through monitoring of deep horizontal displacement and surface displacement, the exact position of the slide surface was found, analyzing the whole deformation process scattered on the body and turn into landslide without retaining after slope excavation, to provide a basis for emergency design of landslide. Through analyzing the amount of deformation observation data of scattered insequent landslide, the landslide displacement characteristics before and after rock reinforcement were obtained. Research conclusions:(1) The deformation characteristics of the scattered insequent landslide are scattered in front, slip in after, the landslides are generally converted by scattered together. Landslide attaches scattered body and the slide zone part attaches to scattered zone. (2) Through monitoring data, the exact position of the slide surface was found, the whole displacement development and changes of scattered landslide were monitored and truly described. (3) The landslide retaining arrangement prestressed anchor can take the initiative to protect the slope and play a significant reinforcing effect to broken rock and landslide deformation. (4) The research result can provide a basis to landslide emergency design and win the time for the landslide protection, and provide reference and empirical criteria for the construction and design of this kind of slope. © 2016, Editorial Department of Journal of Railway Engineering Society. All right reserved.
Liu S.-Y.,Nanjing Southeast University |
Li H.-J.,Nanjing Southeast University |
Tong L.-Y.,Nanjing Southeast University |
Song W.-F.,Shandong Zhengyuan Construction Engineering Co.
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2016
With the speeding up of urbanization, the study on polluted erosive durability of urban underground structures has become the focus of the engineering researchers. Based on a lot of literatures, the worldwide research history and situations of polluted erosive durability of urban underground structures are summarized, and the corrosion mechanism, test methods and influence factors for concrete and reinforcement are discussed. The conclusions of the existing pollution diffusion models as well as some typical laboratory test results about degradation of underground structures are compared, while the life prediction theories of structural durability under coupling action from double corrosion of SO4 2- and Cl-, stress corrosion and corrosion fatigue and the polluted erosive durability characteristics of two kinds of typical urban underground projects are analyzed. Finally, the problems and insufficienly, research thinking and development direction are put forward after summarizing the existing research results so as to promote intensive study on polluted erosive durability of urban underground structures. © 2016, Editorial Office of Chinese Journal of Geotechnical Engineering. All right reserved.
Liu Y.,University of Jinan |
Liu Y.,Center for Monitoring Research |
Liu J.-Y.,University of Jinan |
Liu J.-Y.,Center for Monitoring Research |
And 2 more authors.
Yantu Lixue/Rock and Soil Mechanics | Year: 2016
Through the indoor model test, using the visual tracking technology, through observing the soil displacement field of anchor in the drawing process, and the soil particle porosity and particle trajectory tracking, and then the mechanism of anchor and soil nail is studied. The study found that the particles in the process of pulling anchor for the shear effect of the soil particles move to the soil nailing mobile, but because the boundary constraint of soil nail, the particles reverse, the final compaction zone is formed between the anchor and the soil nailing; the formation of compaction zone not only decreases the soil displacement, but also make the limit of soil nailing, and anchor pullout capacity is improved, which explains why the anchor composite soil nailing can decrease the soil displacement. The study results can provide a theoretical basis for the design of and construction of the anchor composite soil nailing. © 2016, Science Press. All right reserved.
Yang W.-D.,Shandong University |
Zhang Q.-Y.,Shandong University |
Zhang J.-G.,Shandong University |
Zhang J.-G.,Shandong Zhengyuan Construction Engineering Co. |
And 2 more authors.
Yantu Lixue/Rock and Soil Mechanics | Year: 2010
Time-dependent deformation behavior of rock has a significant impact on the stability of rock slopes or underground constructions, and more and more attention is paid to the rheology of rock. However, most rock rheological constitutive models supplied by FEM software have specific usage, and the requirement of engineering numerical analysis can not be satisfied. In this paper, the deterioration effect of the rock parameters is considered and an improved Burgers creep damage constitutive model with variable parameters is established. In this model, the creep parameters of the rock deteriorate with time gradually that makes up the defect of rheology models in FLAC3D. Based on the second development program interface of FLAC3D Version 2.1 software, the basic principle of the second development program for the creep damage is analyzed. The program flow diagram on the special execution of this rheological model and several case techniques that should be taken into account in the process of code compiling are given. Several degradation modes of this model are introduced; and visco-elasticity, plasticity and damage mechanical characters are got through a numerical example. The influence of damage parameters on creep curve is analyzed; and the approach to verify the right and credibility of the second development program compiling is proposed. The second development environment is more friendly and effective with the support of object-oriented approach. Therefore, proposed design mode can bring forward references for the second development of other rheological models.
Yin Q.,China Nuclear Power Engineering Co. |
Liu J.,China Nuclear Power Engineering Co. |
Shang W.,China Nuclear Power Engineering Co. |
Li L.,China Nuclear Power Engineering Co. |
Hou M.,Shandong Zhengyuan Construction Engineering Co.
Electronic Journal of Geotechnical Engineering | Year: 2016
To design a permafrost thaw cycle apparatus, based on the boundary of this undertaking different freeze thaw cycle test at a temperature of silty clay. The results showed that increased coefficient of thaw settlement with dry density tended to increase after the first decrease, there is a critical dry density, so that in this dry density conditions, coefficient of thaw settlement is minimized. Coefficient of thaw settlement with increasing moisture content increased gradually, there is critical water content greater than the water content of soil under conditions of heavy frost heave and thaw can occur. Coefficient of thaw settlement with the temperature gradient freeze showed an increasing trend, but the rate decreases. With the traditional unidirectional freezing-thawing compared to unidirectional, bidirectional freezing-thawing better reflect the way the soil freezing and thawing permafrost regions of the state, and the soil thaw settlement coefficient is small. © 2016 ejge.
Yan N.,Ocean University of China |
Yang J.,Ocean University of China |
Dong M.,Ocean University of China |
Song W.,Shandong Zhengyuan Construction Engineering Co.
Harbin Gongye Daxue Xuebao/Journal of Harbin Institute of Technology | Year: 2016
A series of model tests on friction piles in corrosive foundation model were conducted to investigate the settlement characteristics of friction piles (end-bearing friction pile and friction pile) under working load in corrosive foundation. The copper sulfate solution as the corrosive medium was adopted to make the foundation model, which could accelerate surface deterioration speed. Then the settlement law of friction piles with surface deterioration under working load was investigated. The results indicated that the deterioration degree around pile surface increases with time, and the settlements increase with the deterioration degree. The load-settlement curves of end-bearing friction pile and friction pile were different. After 17360 minutes under working load, the percentage of settlement on end-bearing friction pile reaches 28.5% of pile diameter. The settlement caused by skin deterioration is 10.6% which is larger than the settlement of friction pile with 7%. By the end of the test, the settlements of two types of piles reach the settlements corresponding to the ultimate bearing capacities respectively. Surface deterioration can cause significant incensement of friction pile settlement. This may affect the pile normal function. © 2016, Harbin Institute of Technology. All right reserved.
Zhang Y.,Nanjing University |
Wang H.-M.,Shandong Zhengyuan Construction Engineering Co. |
Yan L.-F.,Nanjing University
Yantu Lixue/Rock and Soil Mechanics | Year: 2013
In order to research the tensile properties of compacted clay, a conventional triaxial test apparatus was modified to a uniaxial tensile apparatus for clays, by which clay samples can be extended and the stress and corresponding strain of the samples can be measured directly. A series of laboratory tests were conducted to investigate the tensile properties of compacted clay. The tested clay samples have various moisture contents (from 16% to 24%) and various dry densities (from 1.29 g/cm3 to 1.65 g/cm3), which have impacts not only on the tensile strength of samples, but also on the pattern of tensile stress-strain curves. It is found that there are three patterns of stress-strain curves for the tension of clay soil, i.e. strain-softening, strain-hardening, and strain-strengthening, corresponding to the increasing tensile strength and failure strain. The tensile strength of compacted clay approximately increases with its dry density and decreases with its moisture content linearly. With the increasing dry density and decreasing moisture content, the pattern of stress-strain curves of the clay samples changes from strain-softening to strain-hardening, then to strain-strengthening pattern. The tensile rate has obvious effect on the measured tensile strength and the pattern of stress-strain curves. For the samples with identical dry density and moisture content, lower tensile rate results in smaller measured tensile strength and strain-softening stress-strain curves; and higher tensile rate causes greater measured tensile strength and strain-strengthening stress-strain curves.
Han K.,Northwest Research Institute Co. of C. R. E. C |
Si X.-D.,Shandong Zhengyuan Construction Engineering Co.
Journal of Railway Engineering Society | Year: 2015
Research purposes: Qingdao Hualoushan Road Metro Station is in slightly weathered rock, on the both ends the composite rock bolting and shotcrete and suspending pile supporting modes open excavation method is used, on the middle section three-bench seven-step excavation method and blasting construction are used. Taking the station project as the background, the deformation law of main station and the surrounding environment was studied by in-situ monitoring test, the construction deformation characteristics of large span metro station in hard rock area were analyzed, the deformation rules were summarized, to provide the reference for the similar engineering construction. Research conclusions: (1) The surface settlement of composite rock bolting and shotcreting section is smaller than suspending pile supporting, the surface subsidence of initial excavation increases fast, and tends to be stable with excavation to floor position. The maximum settlement of the open excavation section is smaller than the subsurface excavation section. (2) In the same depth position, the anchor force of composite rock bolting and shotcrete section is smaller than suspending pile supporting section. Deep horizontal displacement of suspending pile was "inverted trapezoidal" distribution. (3) In the subsurface tunnel, vault settlement and convergence mainly occur in three stages, namely the excavation stage of the upper bench and on the left and right of the middle bench, and begin to slow and steady with excavation of lower bench. (4) The research results can be applied to the construction field of hard rock and large span metro station. ©, 2015, Editorial Department of Journal of Railway Engineering Society. All right reserved.
Xiang W.,Shandong University |
Zhang Q.-Y.,Shandong University |
Zhang J.-G.,Shandong Zhengyuan Construction Engineering Co.
Yantu Lixue/Rock and Soil Mechanics | Year: 2015
The creep parameters of rockmass are essential data of geotechnical engineering design. To accurately determine the creep mechanical parameters of rockmass, considering the advantages of the analytical inversion method and intelligent inversion method, the analytical intelligence inversion method coupling the analytical inversion and the intelligent inversion is developed. The proposed method is applied to the Dagangshan hydropower station project to obtain the compressive creep parameters of rockmass in dam zone. The results show that analytical intelligence inversion creep curves are more coincident with experimental creep curves than the analytical inversion creep curves, proving that the creep parameters obtained through the analytical intelligence inversion method to be more accurate and reliable, and hence the validity and rationality of this inversion method are also verified. The method provides an important theoretical guidance for efficient rheological parameters inversion of rockmass in dam area. ©, 2015, Academia Sinica. All right reserved.
Li X.,Yantai University |
Han G.,Shandong Zhengyuan Construction Engineering Co. |
Qiao Y.,Yantai University
WIT Transactions on Ecology and the Environment | Year: 2014
Yantai is the core area of the Shandong Peninsula Blue Economic Zone. However, seawater invasion has impacted on the regional ecological environment and has caused a certain degree of harm to the agricultural production and the sustainable development of the regional economy. By analyzing the causes of seawater intrusion in Yantai, 2 first grade indexes of risk assessment of seawater intrusion and 7 second grade indexes are determined. And then, by using an analytic hierarchy process (AHP), each evaluation index weight is determined, and according to the factor of weight overlap, the risk index is determined. Finally the risk regionalization of Yantai coastal areas is made based on the GIS space analysis function. Results show that the high risk regions of seawater intrusion include Laizhou city, Longkou city, Zhifu district; medium risk regions include Haiyang city, Muping district, Penglai city, Laishan district; low risk regions include Zhaoyuan city, Fushan district, LaiYang city. © 2013 WIT Press.