岩土工程技术

Search of Dangerous Slide Path of the Rock Slope Without Obvious Slide Surface

Xiong Chong, Duan Jian

2007, 21(4): 163-166.

[Abstract](27) [PDF 600KB](6)

Abstract:
The algorithm of searching dangerous slide path of the rock slope without obvious controlling discontinuities is improved, and the method of adopting dynamic planning method which is based on the criterion of minimum slide-resisted reserve density to confirm dangerous slide path is proposed. The safety coefficient of slope is verified by an example.

Exception Mining in the Dealing With Monitoring Data of Excavation Slope

Lu Jun, Wang Jing, Jin Jianxing

2007, 21(4): 167-169.

[Abstract](40) [PDF 512KB](7)

Abstract:
Based on the exception mining theory,a progran for the monitoring date processing is compiled. The exceptional date is picked out in the processing of dealing with the monitoring date by the program and the reliability of the monitoring date is improved. The program is tested by practice.

Comparision Experiment of Water Content Redution Methods of Engineering Soil

Zhang Linhong, Wu Huajin, Wang Da

2007, 21(4): 170-175.

[Abstract](41) [PDF 553KB](5)

Abstract:
The natural drainage, vacuum drainage and electro-osmotic drainage are all proved to be feasible in theory. In order to distinguish the feasibility, the drainage methods are experimentized. The drainage efficiencies are all high at the beginning and the effectivenesses of all the methods, the reduction of water content and the improvement of the soil density are verified. The effect of electro-osmotic drainage is proved to be the best of all.

View on Water Level for Prevention of Up-floating

Yang Cuizhu

2007, 21(4): 176-178.

[Abstract](58) [PDF 536KB](19)

Abstract:
Based on the Archimedean Principle, building basement floating accident occurs when the groundwater head pressure beyond the foundation pressure. In order to insure the safe of the building, the safe groundwater level height, referred as water level for prevention of up-floating in general, must be confirmed before the design stage. The current different viewpoints on the determination of water level for prevention of up-floating are verified by the examples,and suggestion which may be a reference to the determination of water level for prevention of up-floating is put forward.

Present Situation of Subway Engineering Exploration and Technology Research Topics

Peng Youjun

2007, 21(4): 179-183.

[Abstract](35) [PDF 437KB](8)

Abstract:
The characteristics of the subway exploration, one is the exploration that not bought the land for construction, the other is the exploration that underground system engineering. The subway exploration of our country experiences the three history development period witch explore,accumulate and standardization, each period carry on works according to four exploration stages that is possibility research exploration,the preliminary exploration, the detailed exploration and implemental exploration. According to the subway design requests and geology circumstance to adopt diversification text instrumentality, exploration contents completely, techniques gradually perfect, have obvious specialization features. Aftertime should be combining the construction's methods and design requirements of metro, research and concluded the test technology of special design indicators, solve the seismic design problem that subway structure at the fourth-saturated water-filled sand, strengthen research adaptability of new technologies and new methods of construction in different geological conditions, we must work hard in security and speedy construction and cost reduction etc.

In-situ Direct-shear Test on Rock-Soil Aggregate

Wu Minshuo, Li Xiao, He Jianming

2007, 21(4): 184-189.

[Abstract](32) [PDF 592KB](6)

Abstract:
There is a lot of loose Quaternary deposit originated from landslide deposits, weathering residues, slope wash and diluvial deposits etc, prevails in the Three Gorges Reservoir area. The mechanical properties of the material are widely different from homogeneous and continuous soil. To emphasize its component and structural characteristic, this special geological material is termed as "rock-soil aggregate"(RSA) in this dissertation. Based on the large number of geological investigations, the genesis types of RSA are generalized. In-situ direct-shear tests are conducted on the landslide. The deformation and failure mechanisms of RSA under shearing conditions are disclosed.

Uneven Settlement of a Building and Its Treatment

Li Mingying, Jin Renhe

2007, 21(4): 190-192,213.

[Abstract](47) [PDF 575KB](8)

Abstract:
Based on the investigation of cracks and uneven settlements of the building,it's recognized that the cause of the accident is the fluctuation of the ground water. And the treatment method, anti-float anchor, carbon fiber reinforcement and encased steel strengthening technology, is put forward. The reinforcement meets the requirement of construction safety.

Experimental Study on the Deep Overburden of Jiudianxia Dam Site Riverbed

Li Zhanghong, Liu Hongping

2007, 21(4): 193-195,201.

[Abstract](59) [PDF 187KB](5)

Abstract:
Based on the massive experiments, such as the pellet analysis, the penetration coefficient, the dry density, the relative density, the load, the distortion, side presses and so on, the river bed deep overburden layer physics mechanical properties, the hydrology geology characteristic, its physical mechanics parameter is proposed. And the reliable basis for determination of the dam style and the design proposal choice is provided.

Profiles of Matric Suction in Unsaturated Soils in Condition of One-dimensional Steady Infiltration

Wang Meichun, Wang Donglin

2007, 21(4): 196-198.

[Abstract](25) [PDF 320KB](5)

Abstract:
Infiltration and evaporation has great influence on matric suction distributions. Based on water phase continuity requirenent,generalized Darcy's law and Gardner's empirical equation on relationship between coefficient of hydraulic conductivity and matric suction, formulas are established and solved to calculate matric suction distribution in unsaturated soils in the condition of onedimensional steady-state infiltration and evaporation. In single unsaturated soil system, an analytical parametric study is carried out. Parameters,include α,infiltration rate q and q/k_s,are considered in the study.

Advertent Problems in the strength Checking Computation of Soft Substratum

Zhang Gaofeng

2007, 21(4): 199-201.

[Abstract](59) [PDF 342KB](8)

Abstract:
Based on the method of flare angle of pressure checking the strength of soft substratum, which is defined by Code for Design of Building Foundation (GB 50007--2002), some aspects, that can be easy ignored, are introduced. It is emphasized that the conception of flare angle and the key problems that need attention in flare angle sampling on application.

Ground Subsidence and Water Level for Prevention of Up-floating of Beijing Shahe Area

Ma Bo

2007, 21(4): 202-203,217.

[Abstract](44) [PDF 426KB](13)

Abstract:
The ground subsidence and water level for prevention of up-floating of Beijing Shahe Higher Education Park is elaborated. And the corresponding measures are proposed.

Prevention and Anti-frozen Technical Mehtods of the Channels in Alpine Region

Nei Wenjie, Yuan Anli

2007, 21(4): 204-206.

[Abstract](37) [PDF 172KB](6)

Abstract:
The prevention and anti-frozen technical methods of the channels in high cold regions is presented. The methods are all based on the research of the hydraulic structures of Heilongjiang Provincial Hydraulic Research Institute which are from the research result in the recent twenty years. The research includes the determination method of the anti-frozen design parameters, the outlines of the prevention and anti-frozen technical methods of the channel lining projects, etc. It offers some references for the similar engineering.

Engineering Geological Characteristics of Soft Soil in Wenzhou Area

Yang Decai, Wang Huaibo, Xu Jun

2007, 21(4): 207-208.

[Abstract](33) [PDF 216KB](7)

Abstract:
The physical and mechanical indexes, the regional distribution regulary and the relationship between these indexes are systematically analyzed. The technical characteristics of soft soil clay in Wenzhou is researched.

Sediment Influence on the Bearing Capacity of Swivel-driven Pile in the Sandy Soil Strata

Dai Hongjun, Guo Jizhong, Wei Hua

2007, 21(4): 209-213.

[Abstract](32) [PDF 734KB](6)

Abstract:
There are many factors relate to the bearing capacity of piles because of the complex bearing-deformation mechanism, in which sediments have evident influence on the bearing capacity. Comparing with other cast-in-place piles, although the swivel-driven pile possesses special advantage in controlling sediments, the method of adopting the slurry to clean bore usually decrease the bearing capacity of pile in the sandy strata with large thickness. Based on the result of trial piles, the applied effect of swivel-driven pile in the sandy soil and the influence of the bearing capacity due to sediments are objectively analyzed. Useful experience for the application of the swivel-driven pile in the project is offered.

Grouting Treatment of Sedimentary Dregs of Cast-in-place Bored Pile Bottom

Zhao Peisheng, Yu Liang, Wang Wei

2007, 21(4): 214-217.

[Abstract](54) [PDF 498KB](7)

Abstract:
The reasons for sediment,sediment's effect on the bearing capacity of cast-in-place bored pile and treatment with sediment are analyzed,and the effecting mechanism of grouting at the piles bottom is discussed. The technique is emphasized by means of practical work. The test indicates that grouting at the piles bottom is an effective method to deal with sediment and it improves the bearing capacity of piles.

2007 Vol. 21, No. 4