Sand-gravel mixtures are special engineering geological materials between soils and fractured rocks. This study performs a series of bending element tests to systematically investigate the shear wave velocity ( V s ) sand-gravel mixtures, establish an effective evaluation method, assess influence relative density confining pressure on with wide range gravel contents. The results showed that increases then decreases increase in content rise pressure. Furthermore, prediction model is proposed...

In this study we investigated the electrochemical corrosion behaviors of X80 pipeline steel welded joints fabricated by ultrasound-assisted submerged arc (UASAW) in CO2-saturated solution. The microstructures UASAW were analyzed using metallographic microscopy. Corrosion behavior was immersion test, polarization, and impedance spectroscopy (EIS). morphologies products characterized scanning electron microscopy (SEM), energy dispersive spectroscope (EDS) X-ray diffraction. Metallographic...

This paper presents a method for evaluating the lubrication characteristics between piston and cylinder in swash-plate type axial pump-motor under mixed conditions. A numerical analysis is carried out order to obtain metal contact force cylinder, ratio λ shown represent condition both pump motor strokes. The ratio, λ, also obtained experimentally by detecting electric resistance practical machine. experimental result expressed relationship SO (the of dynamic pressure supply pressure) as...

Implant-related infections are one of the major challenges faced by orthopedic surgeries. Developing implants with inherent antibacterial properties is an effective strategy to address this issue. Biodegradable magnesium and alloys have become a research hotspot due their good bioactivity, mechanical properties, biocompatibility, excellent ability. However, its rapid corrosion, difficulty in expelling harmful ions hydrogen gas produced degradation from body. This review summarizes mainstream...

In this paper, the longitudinal seismic response characteristics of utility tunnel subjected to strong earthquake was investigated based on a practical project and numerical method. Firstly, generalized displacement method (GRDM) that used conduct study reviewed briefly. Secondly, information referenced engineering finite element model introduced in detail, where novel joints between segments presented. Thirdly, series were provided, including inner force intersegment opening width. The...

In the past 500 years, many moderate to strong earthquakes have occurred in or near Beijing metropolitan area, which is underlain by thick Quaternary and Tertiary sediments. Therefore, area susceptible damage associated with ground-motion site effect, particularly for large number of high-rise buildings. order understand earthquake effect potential, context buildings, we are undertaking an effort construct a 3-D shear-velocity model sediments area. this paper, present integrated method...

The shear-wave velocity of rock and soil masses is the quantitative basis for understanding dynamic parameters site evaluating its performance.The field test laboratory are two major methods it necessary to study difference results obtained by methods, especially conventional soils like silt silty clay.This selected typical sites conduct tests measured velocities undisturbed samples clay in laboratory.The suggest that: (1) almost all were faster than those test; (2) main reason causing...

Lubrication condition between a piston and cylinder produces large influence on the performance of swashplate-type axial pistons pump motors. It is desirable to have fluid lubrication for these sliding parts so as decrease friction abrasion. Understanding extreme importance efficient larger operating ranges. Therefore, we advocate necessity observing evaluating degree metal contact separation based film under mixed condition. In this report, attempted measure spinning, observed evaluated...

Lubrication between the piston and cylinder of a swashplate type axial pump or motor affects performance greatly. It is desirable to make fluid lubrication condition in this sliding parts so that decrease friction abrasion. Understanding very important optimal wide operating ranges.In report, degree metal contact separation based on film observed by measuring voltage (contact electric resistance) under constant applied across cylinder. Further, effects each radial clearance examined...

Sand-gravel mixtures are typical binary materials, exhibiting highly heterogeneous, discontinuous, and significant structural effects. The contact state between sand gravel particles has a influence on the mechanical properties of mixtures. This article focused complex internal structure its mesostructural behavior mixtures, systematic statistical analysis was carried out to study shape, size, angularity coarse particles. three-dimensional (3D) shapes aggregates were approximated be...

The effects of marine and continental sedimentary environments geological ages on the dynamic shear modulus ratio damping Quaternary soils in offshore areas Yellow Sea were analyzed by using a resonant column device (GCTS, USA). results show following: (1) <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1"> <msub> <mrow> <mi>G</mi> </mrow> <mi mathvariant="normal">max</mi> </msub> </math> various increases with depth shows typical linear relationship. (2) transgression has...

Most of the coastal beach zone in world is rich wind energy reserves and has great potential for offshore power development. However, sedimentary environment area complex changeable, nature foundation soil platforms weak complex, which quite different from that land areas. In order to systematically study mechanical properties marine soils, a series geotechnical tests are carried out on representative undisturbed seabed such as basic laboratory tests, bender element undrained triaxial shear...

Numerical analysis is carried out in order to express the mixed lubrication characteristics between piston and cylinder swash-plate type pump motor. The distributions of fluid film pressure contact force are calculated, λ(the ratio)is obtained for both motor strokes. characteristic expressed by relationship λ S0(the ratio dynamic static pressure). validity numerical discussed through comparison with experimental results reported so far present authors. It shown that λ-S0 curve independent...