http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Bentian Yu (검색결과 3 건)
- 무료
- 기관 내 무료
- 유료
-
Bentian Yu,Haoqi Zhou,Junying Xia,Xiaolin Liu,Chao Xie,Kai Zhang 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.9
To research the performance of low-temperature sulfate corrosion resistance of concrete mixed with stone-powder in saline soil area of Qinghai-Tibet Plateau. In this work, the influence of the water-to-binder ratio and stone powder types on the low-temperature sulfate erosion behavior of cement-based materials was studied, and in order to predict its erosion life, a Wiener stochastic process model was established. The results show the following: 1) The samples of limestone powder cement-based materials (LCBM) with different water-to-binder ratios showed the same law in sulfate erosion; the greater the water-to-binder ratio is, the more serious the sample is eroded, and the difference is the rate of erosion reaction. The greater the water-to-binder ratio is, the earlier the characteristic peak of thaumasite appears. The electric pulse accelerated erosion lifetimes of the cement-based limestone powder with water binder ratios of 0.3, 0.4 and 0.5 were 185 days, 136 days and 110 days, respectively. 2) Quartz stone powder cement-based materials (QCBM) showed different erosion laws compared with LCBM. When soaked in sulfate, the macroscopic and microscopic changes of QCBM were basically in a mineral additives state, However, when the electric pulse accelerated the erosion, the QCBM was more severely attacked than the LCBM. The final erosion products of the cement-based limestone powder with water binder ratios of 0.4 are not only gypsum and ettringite but also thaumasite, while the quartz powder cement-based materials with water-binder ratios of 0.4 are only gypsum and ettringite.
-
Method to Estimate Lateral Earth Pressure on High-Filled Cut-and-Cover Tunnels
Li Ma,Sheng Li,I-Hsuan Ho,Qicai Wang,Bentian Yu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.3
High-filled cut-and-cover tunnels (HFCCTs) can be used in northwestern China to reclaim usable land. Because of the ultra-high backfill used in HFCCTs, the stress on the cut-and-cover tunnel (CCT) will change. However, The calculation method adopted at present for earth pressure usually result in either overestimation or underestimation. Different from vertical earth pressure, lateral earth pressure (LEP) can help stabilize the structure of HFCCTs. The current methods for estimating LEP rely mainly on Rankine’s theory or empirical formulas. Using conventional methods has led to errors between actual values and estimated values, and such deviation increases with an increase in the backfill height over the CCT. Due to the complex soil-arching effect, the current methods used for calculating LEP for HFCCTs need to be modified. These modifications need to consider characteristics of the CCT, mechanical properties of the backfill soil, and the geometry of the landform. In this work, several influential factors were identified through numerical analysis using the finite element method and propose four corresponding coefficients of modification: k0, the cross-sectional shape of the CCT; k1, the mechanical properties of the backfill; k2, the width of the CCT; and k3, the coupled effect of the slope angle and ratio of the width of the valley floor to the width of the CCT. Because current methods and specifications may overestimate the LEP for HFCCTs in valleys, a general equation was formulated for modifying the LEP coefficient. Also, this general modification equation was verified that agrees well with the numerical analysis results for different cases.
-
Sheng Li,Yuchi Jianie,I-Hsuan Ho,Li Ma,Qicai Wang,Bentian Yu 대한토목학회 2020 KSCE JOURNAL OF CIVIL ENGINEERING Vol.24 No.6
The use of high-filled cut-and-cover tunnels (HFCCTs) provides an ideal solution for reclaiming usable land in northwestern China because of the unique landforms of the Loess Plateau. Different from traditional tunnel boring methods, the HFCCT is first constructed and then backfilled in layers in the trench. Due to the backfill above the cut-and-cover tunnel (CCT) is required in quantity, currently, the existed estimating methods of the earth pressure may not suit the high-filled constructions. The ability to estimate the load on such tunnels and high backfill projects is extremely important. Conceptually, the Marston-Spangler (M-S) theory for buried culverts may be used to estimate earth pressure on HFCCTs. However, the earth pressure would be quite different from that of buried culverts in terms of the backfill volume, cross-sectional shape of structure, and foundation conditions. This paper presents physical experiments and numerical investigations to verify the influence of cross-sectional shape (arch and rectangle) of CCTs, foundation settlement, and load reduction using expanded polystyrene (EPS) for the vertical earth pressure (VEP) distribution and vertical displacement around a CCT. The experimental results agree well with the numerical analysis results. Moreover, further comparisons were also made to analytical analysis based on M-S theory. The comparison results indicate that analytical solutions for buried culverts cannot be applied to HFCCTs directly. In order to obtain the earth pressure accurately, designers must consider many influential factors.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
