Applied Mechanics and Materials Vols. 256-259

Abstract: It is well known that the slope stability analysis is the core of the slope engineering study .The key of the study slope safety stability is optimize the slop coefficient。And the reasonable coefficient decides the design of slope type structure.This paper used the simplified Bishop method which according to the limit equilibrium theory as the foundation and the finite element numerical simulation to solve the south-to-north water transfer engineering slope instability problem.So it can provide the theory basis and design opinion for the slop construction engineering in the future.

Abstract: Group excavation engineering is a typical engineering roadblock in the process of urban underground space development . The concept of group excavation engineering was put forward and its features was described combined with practical engineerings. On the base of analysising the sections relevant group excavation engineering in Chinese codes, suggestions were given in the aspects of engineering investigation,design,construction and monitoring. At last,we point out that the theory is far behind the practice application in group excavation engineering.

Abstract: Concerning the stress and displacement of the partner under lateral load, reference on full-scale model tests on behavior of cast-in-place concrete pipe piles, two cases are analyzed by means of 3D finite element method, calculations show that in condition I, pile and cap rigid joint (pile foundation) plus partner, partner block the punching stress from pile top to cap continue to spread; and in condition II, the distance between pile top and pile cap is 200 mm, partner is in normal bending shear state; As the flexural rigidity of partner is much larger than the pile, if under earthquake or other rare action, partner may sacrifice firstly to keep pile perform well.

Abstract: Based on field survey sampling and indoor test of four big quarry rock in Wulumuqi, rock's engineering geological properties is system analyzed. Investigation and test results show that there is mainly sedimentary sandstone in the area, the composition of the substance is mainly debris, feldspar and quartz.Debris content of 60% or more, feldspar and quartz content of about 30%, cementing material is mainly made up of argillaceous and carbonate class whose ratio is about 10%. The compressive strength is higher in the natural state, the general in between 30 MPa-90MPa. In different moisture content state the compression strength are very different.Compared saturated state to dry state, the compressive strength reduced by about 40%. Tensile strength, flexural strength, shear strength and elastic modulus increase with increase of compressive strength. The same kind of rock in the same moisture content which tensile strength is only the 1/15-1/25 of the compressive strength, the flexural strength is the 1/4-1/7 of the compressive strength. Sandstone frost resistance is better, after 25 times the freeze-thaw cycle test, its strength is lower slightly and quality is not damaged.

Abstract: Using FLAC3D Software for Analysis of Foundation Pit, the Stress that Caused by Sidewall Displacement of Foundation Pit Has Been Analyzed. the Influence Scope and its Rules of Foundation Pit Three-dimensional Effects Were Obtained.

Abstract: Deep foundation pit engineering is a comprehensive geotechnical problems, has distinct regional. In recent years, it has become the hotspot in geotechnical engineering. The key technology of deep foundation pit engineering rapid development in recent years such as soil test, the design and construction of retaining and protecting, monitoring, dewater. The use of computers in the calculation theory and monitoring technology of deep foundation pit engineering makes two parts have changed in essential. This article discusses the soil test, retaining and protecting technology and principle, the monitoring and dewater of deep foundation pit engineering. The development of deep foundation pit engineering situation and the problems exist of the development of deep foundation pit engineering, which have important meaning to guide the engineering practice and discipline new fields of explore.

Abstract: Through indoor the compaction test and unconfined compressive strength of compacted soil samples and CBR strength test, analyzes compaction characteristics of wetland fine grained soil and the change rule of compacted strength with compaction work and moisture content.The results show that under the same compaction work effect, when the soil moisture content is less than optimum moisture content,along with the increase of moisture content, dry density increases, when the soil moisture content is greater than the optimum moisture content, along with the increase of moisture content, dry density decreases and to a larger extent.When the compaction work is bigger, the soil dry density is bigger, the compaction strength is higher and the optimum moisture content is smaller.Strength decreases when under high moisture content condition, CBR value is relatively stable in the wet side of optimum moisture content.

Abstract: Aiming at frost heave problem existing in tunnel construction with artificial horizontal ground freezing in coastal areas, this paper puts forward an equivalent load method for frost heave simulation and a nonlinear deformation simulation method for soil around frost wall. Employing the numerical test method, the designing parameters’ influence on ground frost heave is studied systematically. These parameters include depth of tunnel, frozen wall thickness, excavation radius of tunnel and frost heaving ratio. Furthermore, some measures are proposed to reduce ground frost heave.

Abstract: Large-jointed rock mass is the main geological condition of transmission lines of Qingyuan Regions in Guangdong Province. The bolt foundations haven’t be studied and applied in this geological condition. Static load tests of 15 single-bolt foundations and 8 group-bolt foundations were carried out. Experiment study shows that the mechanical characteristics of bolt foundation are suitable for transmission lines in large-jointed rock mass. The design parameters of anchor bar in large-jointed rock mass are derived from the measured data:τa>2359kPa, τb>618kPa, τc>42kPa.

Abstract: The rise and fall of water level has great effect on the slope stability. Based on the saturated-unsaturated seepage theory, the article has an intensive study of the seepage flow field and the change law of the stability safety factor of the slope stability under the condition of fluctuation of water level. The slope stability safety factor is changing in the process of water level’s rise and fall. with the carrying out of the impoundment, slope stability safety factor decreased. The water level rises in the water lever’s rising process. Due to the penetration of water penetration, the reduce of the shear strength of rock and soil, as a result, the slope stability safety factor reduced. as the water level increased gradually, slope stability safety factor increased. After two or three days later, the slope stability safety factor tends to a stable value.