岩土工程技术

Lab Model Testing on Piping-filter Prevention in Broadly Graded Sandy Soil

Bai Yanfeng

2012, 26(1): 1-5. doi: 10.3969/j.issn.1007-2993.2012.01.001

[Abstract](51) [PDF 727KB](7)

Abstract:
By using visual tracing techniques, real-time digital process techniques and non-target measuring techniques,the lab model tests on base soil-filter of broadly graded sandy soil were carried out. The applicability of the filter-layer standard has been discussed; different filter layer thickness and compression rate on piping development influence has invested. The resuits proved that: the traditional Terzaghi filter guideline is improper for broadl graded sand, d₈₅ of moving particles can be used in the design guideline; Increasing filter layer thickness could improve that the system of the seepage failure, but the system penetration ability only improved a little; hydraulic gradient increases faster is not conducive to the stability of the system.

Evaluation of the Exploitation of Geothermal Resources in Beijing Region

Lin Ye

2012, 26(1): 6-8,13. doi: 10.3969/j.issn.1007-2993.2012.01.002

[Abstract](21) [PDF 651KB](5)

Abstract:
Geothermal is the heat resources from inner earth that can be exploited for our daily life usage. They are eco-frierdly energy sources that can be utilizable for industry and agriculture, with huge market potential. It is also a relatively clean alternative energy. Evaluation of the geothermal exploration will help the relevant regions to the effectively utilization. In this paper, taking a geothermal well in Beijing as an example, geothermal resources are evaluated by the hot temperature, mineral content, extraction, water quality and so on. In water quality evaluation, application types of geothermal resources are analyzed and evaluated by the medical evaluation, drinking mineral water evaluation, drinking water evaluation. In medical applications, medical effects on the human body are evaluated from the mechanical, temperature, chemical composition of geothermal water. This paper not only provides information on comprehensive utilization of geothermal resources for geothermal well, but also for the relevent areas as well.

The Monitoring and Analysis of the Baotong Temple Subway Station Foundation Pit Engineering in Wuhan

Xu Sheng, Xiao Mingzhao

2012, 26(1): 9-13. doi: 10.3969/j.issn.1007-2993.2012.01.003

[Abstract](63) [PDF 753KB](9)

Abstract:
This paper has introduced the foundation pit supporting design and monitoring program of the wuhan railtransit line 2 at a phase of the project section of 20, the Baotong temple subway station, And also made a preliminary analysis for the monitoring results of geotechnical engineering foundation pit lateral horizontal displacement and strut axial forces. The result indicated: soil layer and rock layer in the process of foundation pit excavation in the lateral deformation degree level is large, and the state of the different soil lateral level have different deformation degree. Due to the relative to the rock soil lateral deformation is bigger, the supporting shown by the inside of the strut axial forces are also relatively large. So, for different formation, carries on the soil foundation pit support scheme should choose reasonable design for optimization purpose according to their different deformation properties, soil and rock strata can take on different support form to get to both safe and economic purposes.

Normalized Stress-Strain Behavior of Dredged Clayey Soils in Triaxial Undrained Shear Test

Ni Junjun, Cui Jianjian

2012, 26(1): 14-17. doi: 10.3969/j.issn.1007-2993.2012.01.004

[Abstract](53) [PDF 732KB](6)

Abstract:
It does a great reference value to link the stress-strain relationship of Dredged Clayey Soils with water content for actual projects. Traditional researches on normalized stress-strain behavior of remolded soils is just for a specific kind of soils concerned,which obviously has some limitations. The normalized factor w/w_L is introduced to normalize the ultimate value of principle stress difference, which refer to the linear relationships between the ultimate value of principle stress difference and w/w_L in double logarithmic coordinates.On this basis, the research on normalized stress-strain behavior on three different kinds of Dredged Clayey Soils,which is based on the hyperbolic model proposed by Konder and aqopted the ultimate value of principle stress difference as the standard normalized factor.It shows a good normalized results by comparing with the experimental results.

Dynamic Consolidation of Soft Soil and Rubber Soil Treatment Technology

Yang Wenjing

2012, 26(1): 18-22. doi: 10.3969/j.issn.1007-2993.2012.01.005

[Abstract](52) [PDF 683KB](12)

Abstract:
The Analysis over soft soil foundation by dynamic compaction and dynamic compaction process before the local rubber soil genesis havebeen discussed in this paper. Using differential methods the conclude the various preventive measures and diffevent treatment methods Used, The relevant results can be usedas refevence parposes for similar projeets,

An Overview of the Deep Cover Exploration Techniques and Methods of the Dadu River Anning Hydropower

Li Zhiyuan, Huang Xiaojun, Zhang Yanqin

2012, 26(1): 23-27. doi: 10.3969/j.issn.1007-2993.2012.01.006

[Abstract](29) [PDF 782KB](7)

Abstract:
This paper indicated that the deep cover exploration techniques and methods used in Dadu River anninghydropower feasibilities: φ130 plant gum drilling technology, φ139 thick-walled tube with the tube drilling technology, multi- level drill with drill pipe into the processes; and also described the cover drill hole next to the pressure tests and the original sand sample taken technology. The exploration in deep cover on the application of technologies and methods had ensured the successful completion of exploration work. For detailed calculations, designs, reliable and comprehensive parameters, It also improved exploration technology to improve the level of exploratinn for future work

Mechanical Effect Analysis of Wholly Grouted Anchor in Layered Soil

Zhou Dan

2012, 26(1): 28-30,45. doi: 10.3969/j.issn.1007-2993.2012.01.007

[Abstract](41) [PDF 715KB](11)

Abstract:
Based on the shear displacement method and characteristics of soil distribution, the analytic solutions arepresented for anchor displacement, shear stress and axial force of wholly grouted anchor embedded in layered soil under pull force, the correctness is verified by engineering example compared with FLAC numerical calculation. It is discovered that the distribution curves of anchor shear stress have jump points, and the distribution curves of anchor axial force have turned the points in the layered soil interface, the amplitude of variation have some connection with physical and mechanical properties of layered soils, so, the installment measure of wholly grouted anchor embedded in layered soil is suggested.

Impact Analysis of Tunnel Construction in Steep Rock Slope

Zhang Jinpeng, Wu Honggang, Yu Yunyan

2012, 26(1): 31-35. doi: 10.3969/j.issn.1007-2993.2012.01.008

[Abstract](62) [PDF 1332KB](7)

Abstract:
Landslide is quite regular in steep rock slope due to the engineering geological condition, hydro-geologicalcircumstances, and some human activities, For the landslide formation feature, the geological condition and the hydro geological condition of Masangba tunnel of Wudu-Guanzigou Expressway, several kinds of working conditions of this land-slide is analyzed by using flac3d. Finally, the reinforcement scheme is proposed and proved to be effective.

Frost-Heaving Adaptability Research on Gabion Mat in Large Channel With High Ground Water Level in Seasonal Frozen Soil Region

Yuan Anli, Han Lei, Zhang Bin

2012, 26(1): 36-39. doi: 10.3969/j.issn.1007-2993.2012.01.009

[Abstract](31) [PDF 730KB](7)

Abstract:
It is freguenthy seen that the freeze-thaw of the foundation could damage the revetment in seasonal frozen soilregions. In high ground water level condition, the compositive indexes of the large channel panels are higher because of the high moisture content, strong frost heave and powerful ice thrust in foundation soil. Based on the lab experiments and the demonstration projects, Gabion structures can not only reduce the moisture content before freezing effectively and improve the adaptability to the freeze-thaw of the foundation, but also restore the environment. The conclusions can beused as references for consummating the anti-frozen theories and practical experiences.

Finite Element Simulation on Settlement of Soft Seawall

Jin Degang

2012, 26(1): 40-45. doi: 10.3969/j.issn.1007-2993.2012.01.010

[Abstract](45) [PDF 842KB](6)

Abstract:
Reclamation seawall project is located in the soft ground directly, which Caused the compaction of thefoundation soil, consolidation of drainage and resulting in a larger settlementindex Current calcuIations of the seawall settlement is largely based on the specification datas which mainly uses the sum of layer deposition methods, supplemented by soft soil correction factors. And also combined with comprehensive analysis of the settlement after the consolidation of computing and other similar engineering experience. Different designers tend to have different calculation results. How to determine marine soft soil in the seawall settlement deformation under load accurately is always the major key of the construction and land reclamation projects. In order to investoigate the deformation characteristics of marine soft soil, Basedon the laboratory tests and measured settlement, the author by used Plaxis finite element software to simulate the whole process of the actual projects construction. The author find that usling the elastic-plastic model to simulate plane strain deformation of clay dam settlements, simulation results are close to the measured settlement, and also could simulate the post-construction settlements for future purpose,It also can resolve the large errors resulting bv the exDerienee judgement.

Stability Analysis of Ningbo Beilun Nantian Shipyard Rock Slope

Jin Shujie, An Xiaorui, Ma Jun

2012, 26(1): 46-49. doi: 10.3969/j.issn.1007-2993.2012.01.011

[Abstract](32) [PDF 998KB](7)

Abstract:
The rock slope of Ningbo Beilun Nantian shipyard is formed by blasting the mountain. Without manualprocessing, the rock slope has the character of large angle, strong weathering and joint development, etc. It has already affected the plant's safety, so ws need to make the stability analysis to the rock slope. By the wild--site measures, this article used the Stereographic Projection theoryies to make the stability analysis of the rock slope. Basea on this, it has given the whole evaluation of stability to the rock slope and treatment suggestions.

The Grouting Reinforcement Technique of the Building Adjacent to the Foundation Pit

Tong Gangqiang, Li Hongtao, Guo Jing

2012, 26(1): 50-52. doi: 10.3969/j.issn.1007-2993.2012.01.012

[Abstract](33) [PDF 728KB](11)

Abstract:
Different settlement and large settlement occurred On the building adjacent to the foundation pit during theexcavation process of a metro station foundation pit. The sleeve value barrel grouting construction technologise was used to reinforcing the building. Byi investigating the form of the building foundation, we choose the grouting holes and selected the grouting parameter reasonably, made a good grouting effect, and controlled the building subsidence within permitted.

Theory and Practice of Pile Length Test With Parallel Seismic Method

Wu Shuaibin

2012, 26(1): 53-55. doi: 10.3969/j.issn.1007-2993.2012.01.013

[Abstract](46) [PDF 649KB](7)

Abstract:
The single-hole soniclogging method has been widely applied in Israel, China and other countries.Corresponding equipment and matching software has stepped into commercialization stages. However, the method is mentioned in minor literatures published at home, and relevant contents is slightly rough. The method is described by author in detail and hoping it could give a useful reference to technical personnel and other application in china.

2012 Vol. 26, No. 1