Abstract Excavation gaps around the front shield can be generated during construction, resulting in significant ground settlement. Traditional synchronous grouting slurries are unsuitable for filling these tunneling under existing subway lines. To address this issue, experiments conducted on mix characteristics and hardening properties of with variations fineness contents fly ash. The experimental computed tomography scan results yield following findings: (1) ash high effectively reduce...

Climate warming leads to permafrost degradation and melting phase transition, resulting in an increasing number of landslides. This study uses the road segments area at intersection between Bei'an-Heihe Highway northwest section Lesser Khingan Range north China as area. By means geological survey combined with meteorological data, we analyzed impact climate change on landslide movement zone. Over a 60 year period, average annual temperature has increased by 3.2 °C, is severe. Loose soil...

Background: Adjusting thickening agent proportions in nanoemulsion gel (NG) balances its transdermal and topical delivery properties, making it more effective for dermatophytosis treatment.Methods: Carbomer 940 α-pinene were used as model antifungal, respectively.A series of NGs (αNG1, αNG2, αNG3) containing 0.5%, 0.75% 1% (w/w) developed evaluated stability, rheological skin irritation; assessed ex vivo permeation, deposition, fluorescent imaging drug distribution within layers; tested...

Abstract Ni-base superalloy IN713LC (Inconel 713LC) alloy is used to cast large-scale integral turbine impellers for marine use. Due the large cooling temperature gradient and stress concentration, cracks are prone occur at tip or root of blade. In this paper, structural characteristics microstructure characterized analyzed by OM (Optical Microscope), SEM (Scanning Electron etc. At same time, from composition design master alloy, target distribution ratio each strengthening element adjusted...

Abstract One of the significant challenges faced in shield tunnel construction is risk collapse resulting from abrupt changes soil conditions advance working face, particularly within sandy cobble stratum. This study aims to effectively manage these sudden variations and further investigate failure mechanisms associated with tunneling. The limit support pressure, instability patterns, arch ranges at excavation face under varying burial depths were analyzed using PFC 3D discrete element...

Surface settlement prediction is crucial to assess the safety of subway station construction. To overcome challenges such as missing on-site data and a limited number monitoring points, this study proposes composite model that integrates finite element analysis, time-series interval GA-BP neural network, variational mode decomposition (VMD) techniques. Using Dongba-zhongjie Station in Beijing Subway Line 3 case study, surface predictions were made for both typical points randomly selected...

Abstract To elucidate the wear mechanisms of scraper in shield tunneling through sandy pebble strata, this study aims to achieve high efficiency and low during process. We evaluate operational parameters tool characteristics a 9-m diameter spoke-type machine used on Beijing Daxing Airport Line. The analysis focuses values scrapers rippers, different forms, relative position rippers obtained from field. yielded following conclusions. spokes vary significantly owing ripper protection. can be...

Abstract The operation of a shield tunnel boring machine (TBM) in high-strength hard rock stratum results significant cutter damage, adversely affecting the thrust and torque head. Therefore, it is very important to carry out research on stress characteristics optimize parameters cutters break rock. In this paper, rock-breaking performance an andesite Qingdao Metro Line No. 8 was investigated using discrete element method theoretical analysis. processes disc wedge tooth were simulated by...

Abstract Tool wear is a noteworthy problem in the process of shield tunneling, and degree varies with stratum. The sand‐pebble strata Beijing are typically mechanically unstable. However, many subways buried wholly or partially strata. Taking New Airport line tunneling project as research background, this study evaluated characteristics multiconfiguration rippers 9‐m‐diameter spoke‐type machine values five ripper teeth flanks were analyzed based on field‐measured data from project. As...

Abstract The shallow tunnelling method (STM) often uses temporary supports to divide large section tunnels into several closed or semiclosed sections so as share the upper load. complex support system composed of primary and can ensure safety during tunnel construction. Based on Beijing Subway Line 12, mechanical characteristics by double‐side‐drift (DSDM) excavation demolition were analyzed through numerical simulation monitoring. study showed that middle cave was most critical stage DSDM,...

본 연구의 목적은 다문화가정 청소년의 문화적응스트레스와 심리적 부적응의 관계에서 적응유연성의 조절효과를 살펴보는 것이다. 이를 위하여 광주 · 전남 지역 거주에 거주하는 9-20세의 청소년 216명을 대상으로 설문조사를 실시하였다. 위계적 회귀분석 등을 활용하여 분석한 결과는 다음과 같다. 첫째, 청소년은 종교가 없는 경우, 한국어능력을 낮게 인식할수록, 문화적응스트레스가 많을수록, 적응유연성 수준이 낮을수록 부적응 높은 것으로 나타났다. 둘째, 간의 살펴본 결과, 적응유연성이 집단에서는 많을 때 부적응이 완만하게 높아지는 양상을 보이지만, 낮은 차이의 변화가 상대적으로 크게 셋째, 문화적응스트레스의 하위영역인 적응과정상의 스트레스와 차별스트레스가 부적응에 미치는 영향과 다문화가정청소년의 영향을 변수가 조절하는 이와 같은 연구결과를 토대로 최소화하고, 적응유연성을 강화할 수 있는 정책적 실천적 방안을 제언하고자 하였다.

Bei'an to Heihe highway is being widen expressway at present in Heilongjiang province, some sections are located ancient landslide bodies, influenced by the landform, rainfall, freeze thawing and anthropogenic factors, unstable states, bring great difficulties construction. Took expansion project K177 as research object, employed field investigation, geological drilling, monitoring, indoor experiment numerical simulation methods carry an integrated study on formation mechanism of landslide....

Mechanical properties of sand-pebble layer is very unstable, it unfavourable for TBM excavation. For the reasons poor soil conditioning and low plastic flow muck, EPB tunnel construction in Beijing metro has exposed variety issues: continuous dynamic earth pressure balance hard to established, mud cake formed frequently chamber, key parameters such as thrust, torque, advance speed can not be controlled reasonable scopes, which lead efficiency construction. Taking“Xi-Liu”of line 10 lot 11 an...

In order to effectively control the ground deformation and subsidence during subway construction, three-dimensional numerical simulation of soil shield tunnel construction is proposed. Based on a project, this essay firstly divides process into several stages analyzes vertical displacement in each stage. FLAC 3D was used for finite difference simulation. By comparing results with field measured data, settlement caused by excavation studied deeply. The show that maximum value monitoring data...

The impoundment of the Three Gorges Project (TGP) may influence natural reproduction Chinese sturgeon. From 2009 to 2011, a five-method investigation was conducted analyse this influence. sturgeon reproduced in late November which about two weeks later than 2003 2006. water discharge and temperature did not exhibit any evident difference from 2011. showed that spawning sites transferred near Gezhouba dam 2010 estimated parent greatly increased suggested stopping catching fish number....