Yan Peng Zhu

Numerical Analysis of Composite Soil Nailing Retaining Wall under Earthquake

The seismic response of slope supported by composite soil nailing is analyzed by using finite element software ADNIA, in which the EL-Centro wave is selected as input earthquake wave.The analytical contents include the displacement and acceleration of supporting slope, as well as the time history responses of the axial forces of anchors. In the establishment of finite element model, the interaction between soil body and supporting structure is considered. The elastic-plastic M-C model with nonlinear static and dynamic behavior is used to simulate the soil body, and the dual linear strengthen model is adopted to simulate the supporting structure, then the interaction between soil body and supporting structure is simulated with contact element. The results show that the composite soil nailing slope supporting structure has better seismic performance than the general soil nailing slope supporting structure. The maximum horizontal displacement of the latter occurs at the slope top, but that of the former occurs at the slope upper. Especially after the imposition of the prestress, the slope displacement under earthquake reduces significantly, and the axial forces of anchors under earthquake enlarge significantly. Moreover, the axial forces of anchors reach maximum values near the slipping surface. The displacement and the acceleration of slope increase along the slope height. The conclusions obtained provide basis for the seismic design of permanent supporting slope and reference for similar projects.

Experimental Study on Dynamic Responses of a New Type of Debris Flow Dam under Solid Impact Load

Dams can effectively alleviate great debris flow hazards to downstream regions, so they has been widely applied to prevention and control engineering of debris flow disaster now. A kind of steel-concrete combined structure with steel braces was presented based on conventional gravity dams, and the superiority of the new structure in terms of impact resistance was verified contrastively by means of model experiments under solid impact. The results show that braces can restrain cracks and reduce their width, thus the extent of damage in impact areas is alleviated effectively. Compared with the conventional dam, the dynamic strains and acceleration peak values of the dam with braces both observably reduce, and the highest reduction ranges of them may be up to 69.2% and 47.8% respectively, so the deformation and vibration are limited by the braces. The dynamic displacement peak values of the new-type dam are significantly less than the conventional dam, and the average reduction range of this index can reach to about 46%, so the structural stiffness has been enhanced by a large margin.

Research of the Health Monitoring System Scheme for High Slope in Zhouqu

The target of this paper is to get proper information of deformation through monitor the health of a large-scale trial. The slope in the process of the governance and reinforced slope are designed in the test in Zhouqu County, Gansu Province. Through Health Monitoring Test to high slope, the teat is to master deformation and internal force changes of the supporting structure, meanwhile determine the trend of slope deformation. It is possible to send out the warning for slope stability. Through researching the program and analyzing the data of future monitoring, it provides a reliable basis of similar slope engineering for future.

Testing and Analysis of Bearing Capacity on Pile Foundation

The application of pile foundation is promoted by the rapid development of the high speed railway, highway, high-rise buildings and big volume weight of building. However, the static load test and low strain test play a very important role in pile foundation inspection and ensurement of the quality of pile foundation engineering. In this paper, combined with the engineering of the basis of a hospital in lanhou, the author analyzed the results of 7 test piles static load test and a large number of low strain test and summarised pile testing contents and methods. At the same time,the bearing capacity of anchor pile in static load test is discussed.

Study on Deformation Property of Coarse Particles (Sulfate) Saline Soil with Field Test

Salt expansion was the main diseases of the salty foundation. In order to study the deformation regularity and quantitative description of coarse particles saline soil ground in natural condition, a field test was conducted in Dunhuang area. The exploratory well with 7.5 m depth (deeper then annual temperature change layer) was excavated on site, and the data of salt content \water content \ground temperature \salt expansion rate were collected. From the test it was found that : salt expansion mainly decided by salt content, salt content and salt expansion rate have approximately a quadratic function relationship; the minimum salt content could cause soil expansion is 1.5‰; The salt expansion force was strong, and the gravitational stress could not suppress the deformation.

Influence of Seepage on Embedded Depth for Anchored Pile Supporting

In the present code, the embedded depth is determined on the multi-pivot support structure to consider the impact of seepage less, and it is verified by anti-seepage stability for single layer aquifer, while the embedded depth is determined not expressly provide for heterogeneity aquifer of the coefficient of permeability difference. However, in the northwest loess areas, the formation is complex, permeability coefficient is variations. To solve this problem, the arctic investigates change law that the impacts of embedded depth variation change on bending moment, the vertical displacement of bottom and maximum flow velocity under seepage, and made a qualitative research model. And the impact of seepage on the embedded depth cannot be ignored and a greater impact on the stability of the pit.

Study of Stability Assessment Method for Deep Surrounding Rock

According to the three characteristics of deep surrounding rock: high stress, high temperature and high seepage, the three field coupling control equation of temperature-stress-seepage are established, the finite element method is used for solution. Considering stress transference of surrounding rock after creep and deformation, the finite element incremental equations is deduced. Combining the finite element method and strength reduction method, The defect of deep surrounding rock stability that never quantitatively assess before was overcome. The proposed calculation method is applied to project, the analysis results show that the proposed method is feasible.

Study on Dynamic Calculation Method of Anti-Slide Pile

A dynamic calculation model of the pile supporting structure with single prestressed anchor for the slope is proposed in this paper. The motion equation of the pile-prestressed anchor is established and the analytical solutions are obtained. In addition the proposed method is applied to a project case to carry out the seismic analysis and design of the pile supporting structure with single prestressed anchor. The calculation model provides a new approach for earthquake analysis and seismic design of slope supported by pile supporting structure with pre-stress anchor.

Pipeline Support under the Loads of Comparative Analysis

This article mainly analyzed the load of fixed and movable pipe supports in the catalyst factory,then classified the load. A calculation was made using MIDAS/CIVIL software modeling. The results show that the bending moment and displacement are all the same in axial of movable and fixed pipe supports, and the axial displacement is influenced heavily by load. Fixed pipe supports are less affected by lateral load, but movable pipe supports are more affected by lateral load. The results can help us to design the pipe supports reasonably.

Concrete Crack Control in Monolithic Concrete Bed Construction of High-Speed Railway in Northwest Area of China

There were some reasons which cause the concrete cracks in monolithic concrete bed construction of high-speed railway. In this paper, combined with the specific situation of monolithic concrete bed construction of high-speed railway in northwest area of China, the states and causes of two kinds of cracks in monolithic concrete bed of high-speed railway were analyzed, the concrete cracking control measures were discussed from the concrete mixture ratio, construction technology and maintenance measures and other aspects, and the corresponding views were put forward. The study results had the important guiding significance on crack controls of concrete structure during the construction process of northwest area.