Analysis of the Tunnel Disease Considering the Unsaturated Loess Matric Suction Effects

2013 ◽  
Vol 859 ◽  
pp. 182-185 ◽  
Author(s):  
Xiao Hui Xue ◽  
Zhong Ming Su ◽  
Zhi Jie Sun ◽  
Fei Song
Keyword(s):  
Plastic Zone ◽  
Shear Test ◽  
Drainage System ◽  
Matric Suction ◽  
Water Infiltration ◽  
Disease Treatment ◽  
Tunnel Support ◽  
Internal Relation ◽  
Unsaturated Loess ◽  
Supporting Force

In order to analysis the internal relation between the matric suction change and the tunnel disease, the paper combines the Dayoushan tunnel as an engineering example, uses the mathematical, field monitoring and model shear test and to analysis the the change rule of the martic suction and the influence of martic suction on the tunnle supporting force and plastic zone. The results show that when the water content is increasing, the unsaturated loess matric suction is reduction, the force of tunnel support is increasing and the radius of plastic zone is increasing. Due to the influence of surface water infiltration, the matric suction of the around soil in Dayoushan tunnel is reduction and cause the crown settlement, landslides and lining cracks. The disease treatment mainly lies in keeping the drainage system is smooth and secure for waterproof. For the similar unsaturated loess tunnel, the research results have reference significance.

scholarly journals Study on Water Characteristic Curve and Shear Characteristics of Typical Unsaturated Silty Clay in Shaoxing

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Ruiqian Wu ◽  
Youzhi Tang ◽  
Shaohe Li ◽  
Wei Wang ◽  
Ping Jiang ◽  
...  
Keyword(s):  
Shear Strength ◽  
Internal Friction ◽  
Unsaturated Soil ◽  
Direct Shear Test ◽  
Shear Test ◽  
Characteristic Curve ◽  
Friction Angle ◽  
Matric Suction ◽  
Silty Clay ◽  
Direct Shear

In order to probe into one simplified method to predict the shear strength of Shaoxing unsaturated silty clay, the test method combining unsaturated soil consolidation instrument and conventional direct shear instrument is used to study the shear strength, and the method is compared and verified with the results of equal suction direct shear test. The research results show that the soil water characteristic curve fitted by the measured data points and VG model has obvious stage characteristics in the range of 0~38 kPa, 38~910 kPa, and 910~10000 kPa. The shear strength of unsaturated soil measured by consolidation meter combined with conventional direct shear test is in good agreement with that measured by equal suction direct shear test in the range of 0~500 kPa. The results show that the shear strength, total cohesion, and effective internal friction angle of soil increase slightly with the increase of matric suction in the range of 0~38 kPa. When the matric suction increases from 38 kPa to 500 kPa, the shear strength and total cohesion force of the soil have similar stage characteristics with the SWCC, which first increases and then tends to be stable, while the effective internal friction angle changes slightly. Finally, taking the air-entry value as the demarcation point, an improved model of unsaturated shear strength is proposed by analyzing the error value. Compared with the measured value, the absolute value of relative error is basically kept in the range of 5%~10%, which is close to the measured value.

On the Stability of Unsaturated Loess Slope under Tunneling Condition

2011 ◽  
Vol 233-235 ◽  
pp. 2678-2681 ◽  
Author(s):  
Xi An Li ◽  
Rong Jian Li ◽  
Gao Feng Che ◽  
Wen Zheng ◽  
Liang Li
Keyword(s):  
Critical Factor ◽  
Matric Suction ◽  
Strength Reduction ◽  
Sliding Surface ◽  
Negative Effects ◽  
Loess Slope ◽  
Stability Of Slope ◽  
The Stability ◽  
Unsaturated Loess ◽  
Work Done

As a unique mode of soil erosion, loess cavities often act as the critical factor to the stability of the highway slopes of unsaturated loess. In this paper, the unsaturated loess slope stabilities are comparatively studied in different cases through the developed program of the strength reduction FEM, such as loess cavities in different position, single- & twin cavities, occurrence and loss of matric suction etc. The work done in this paper revealed the mechanism how the tunneling and the matric suction have effect on the stability of unsaturated loess slope to some extent. The results not only indicate that the loess cavities favor to maintain the stability of slope with the cavities located near the slope's crest, while the loess cavities reduce the stability of slope with the cavities located near the slope's toe, but also disclose that the safety factor of the unsaturated loess slope increases and the potential sliding surface move downward with considering the matric suction and vice versa. In addition, the twin cavities near the slope's toe have the obvious negative effects on slope's stability.

Field experimental cells to assess hydrogeological behaviour of store-and-release covers made with phosphate mine waste

2015 ◽  
Vol 52 (9) ◽  
pp. 1255-1269 ◽  
Author(s):  
Bruno Bossé ◽  
Bruno Bussière ◽  
Rachid Hakkou ◽  
Abdelkabir Maqsoud ◽  
Mostafa Benzaazoua
Keyword(s):  
Acid Rock Drainage ◽  
Mine Waste ◽  
Matric Suction ◽  
Water Infiltration ◽  
Mine Wastes ◽  
Acid Rock ◽  
Release Capacity ◽  
Cover Systems ◽  
Phosphate Mine ◽  
Hydrogeological Behaviour

A field investigation was conducted to evaluate the effectiveness of store-and-release (SR) covers made with different phosphate mine wastes in reducing water infiltration (system inclination and surface runoff were neglected) and controlling acid rock drainage (ARD) generation. Four instrumented experimental cells were constructed with different SR layer configurations (two thicknesses and three materials) placed over a capillary break layer. To assess the hydrogeological behaviour of these cover systems, volumetric water content, matric suction, and meteorological monitoring time trends were studied for a period of 1.5 years under actual and extreme conditions typical of an arid climate. Under natural climatic conditions, all net infiltration was released to the atmosphere by the physical process of evaporation (regardless of SR layer thickness and type). Although high surface matric suction (>3000 kPa) decreased the evaporation rate (or release capacity) during the drying period, field tests showed that the studied scenarios limited deep water infiltration even under extreme rainfall events. The release capacity of the SR layer was slightly lower for cover systems made with the finer-grained mine waste (phosphate limestone tailings). This study showed that, for a one-dimensional (1D) condition, the tested phosphate mine wastes have the appropriate hydrogeological properties to be used as components of SR covers under conditions at the Kettara mine site, located near Marrakech, Morocco.

IDENTIFIKASI BENCANA BANJIR KELURAHAN TLOGOSARI KECAMATAN PEDURUNGAN KOTA SEMARANG

Pondasi ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 94
Author(s):  
Andika Duwi Prasetyo ◽  
Agus Sarwo Edy Sudrajat
Keyword(s):  
Land Surface ◽  
Flood Control ◽  
Drainage System ◽  
Flood Disaster ◽  
Water Infiltration ◽  
Drainage Channel ◽  
Eastern Area ◽  
The People ◽  
The Impact ◽  
The City

ABSTRAK Bencana banjir di Kota Semarang sudah tak asing lagi bagi masyarakat Semarang, khususnya pada wilayah timur Kota Semarang, bencana banjir di Kota Semarang disebabkan beberapa faktor antara lain curah hujan yang tinggi, permukaan tanah yang lebih rendah dibandingkan permukaan air laut, dan banyaknya sampah yang tersumbat pada saluran drainase. Bencana banjir yang disebabkan oleh beberapa faktor tersebut berdampak buruk bagi Kota Semarang khususnya pada Kelurahan Tlogosari, Kecamatan Pedurungan, dampak dari bencana banjir tersebut mengakibatkan kerusakan pada jalan, kemacetan, dan dapat menyebabkan penyakit pada lingkungan di wilayah deliniasi di Kelurahan Tlogosari, Kecamatan Pedurungan. Perlu adanya penanganan untuk mengatasi bencana banjir di wilayah deliniasi Kelurahan Tlogosari, Kecamatan Pedurungan, seperti upaya melakukan pembangunan sistem pengendali banjir dan pada sistem drainase, dan pembangunan sumur resapan air pada setiap permukiman, serta melakukan konservasi secara berkala untuk sungai maupun sistem drainase di wilayah deliniasi Kelurahan Tlogosari, Kecamatan Pedurungan. Kata Kunci : Identifikasi; Banjir; Tlogosari ABSTRACT The flood disaster in Semarang City is familiar to the people of Semarang, especially in the eastern area of Semarang City, the flood disaster in Semarang City is caused by several factors, including high rainfall, lower land surface than sea level, and the amount of clogged garbage. on the drainage channel. The flood disaster caused by several of these factors had a bad impact on the city of Semarang, especially in Tlogosari Village, Pedurungan District, the impact of the flood disaster caused damage to roads, congestion, and could cause disease in the environment in the delineation area in Tlogosari Village, Pedurungan District. There is a need for handling to overcome flood disasters in the delineation area of Tlogosari Village, Pedurungan District, such as efforts to build a flood control system and drainage system, and build water infiltration wells in each settlement, as well as carry out periodic conservation of rivers and drainage systems in the delineation area. Tlogosari Village, Pedurungan District.Keyword: Identification;Flood; Tlogosari

Computation for Water Infiltration of Unsaturated Loess

2012 ◽  
Vol 170-173 ◽  
pp. 1915-1919
Author(s):  
Xiao Qiang Wang ◽  
Li Guo
Keyword(s):  
Theoretical Analysis ◽  
Loess Soil ◽  
Calculation Model ◽  
Water Infiltration ◽  
Two Dimensional ◽  
Loess Slope ◽  
Water Leak ◽  
Content Change ◽  
Unsaturated Loess ◽  
Water Content Change

Rainfall and the water leak frequently causes the unsaturated loess slope landslide and the foundation destruction. The theoretical analysis was accomplished, then a two dimensional water seepage calculation model for loess foundation was established. It realized the forecast for the water content change of loess soil. Combined with an example, the calculating program was compiled by Matlab. The result confirmed the effectiveness and rationality of the method and model.

scholarly journals Research on Influence of Road Tunnels with Different Lanes on Surrounding Rock Characteristic Curve

2020 ◽  
Vol 198 ◽  
pp. 02009
Author(s):  
Sun Yang ◽  
Zhang Chengke ◽  
Yu Junping ◽  
Wu Jiangpeng ◽  
Zhu Liqing
Keyword(s):  
Plastic Zone ◽  
Characteristic Curve ◽  
Simulation Method ◽  
Support Design ◽  
Tunnel Support ◽  
Maximum Deformation ◽  
Road Tunnels ◽  
Reaction Curve ◽  
Ground Reaction Curve ◽  
Tunnel Size

Convergence confinement method is an important guidance method for tunnel construction and support design. Numerical simulation method was used to comparatively analyze the ground reaction curve and the plastic zone under different rock grade and roadway tunnel size. The results show that the change of tunnel size has different effects on the maximum deformation of the tunnel arch crown, the ground reaction curve and the plastic zone range. Finally, some suggestions were put forward for the construction and optimization of the large span arch tunnel support structure. The research results may provide some guidance for related engineering

scholarly journals Analysis of Plastic Zone and Pressure Variance Features of Surrounding Rock of High-Altitude Macker Tunnel: A Case Study in Jiangluling Macker Tunnel in Qinghai

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xiaojun Ma ◽  
Hongyan Guo ◽  
Juyi Hu ◽  
Shuang Cai ◽  
Liang Cheng ◽  
...  
Keyword(s):  
Plastic Zone ◽  
Structural Design ◽  
Measurement Data ◽  
Surrounding Rock ◽  
Analysis Method ◽  
Support Structure ◽  
Tunnel Support ◽  
Influence Radius ◽  
Design Of Tunnel Support

Due to the special mechanical properties of macker rock, problems may be caused easily if the pressure of the surrounding rock calculated from the standard empirical equation is used in the structural design of tunnel support, such as obviously insufficient bearing capacity of the support structure, large deformation, and collapse. Taking the Jiangluling Macker Tunnel in Gonghe-Yushu Highway as an example, the distribution pattern of plastic zone of the surrounding rock and the calculation method and reasonable values of pressure of the surrounding rock are studied in this paper, by means of theoretical analysis, numerical computation, and field measurement data. The results show that the elastic-plastic analysis method is suitable for the pressure of the surrounding rock of macker tunnel. The influence radius of the plastic zone of the surrounding rock can be 32 m, and the lateral pressure of the surrounding rock of the tunnel is equivalent to the vertical pressure. In the absence of test conditions and measured data, the pressure of the surrounding rock can be approximately 0.83 MPa for the purpose of design of tunnel support structure. This conclusion provides technical support for projects in similar conditions.

scholarly journals Analysis and numerical calculation of a coupled creep and strain-softening model for soft rock tunnels

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256243
Author(s):  
Jianjun Zhang ◽  
Baicong Yao ◽  
Yunhe Ao ◽  
Chunzhe Jin ◽  
Chuang Sun
Keyword(s):  
Numerical Calculation ◽  
Stability Analysis ◽  
Plastic Zone ◽  
Creep Behavior ◽  
Strain Softening ◽  
Soft Rock ◽  
Support Design ◽  
Tunnel Support ◽  
Accelerated Creep ◽  
Rock Tunnels

Proper mechanical model selection is critical in tunnel support design and stability analysis, especially to reflect the creep and strain-softening behavior of soft rock. We present a coupled nonlinear Burgers strain-softening (NBSS) model and numerical calculation method to investigate the coupled effects of creep and strain-softening of soft rock tunnels. The nonlinear elastic-viscous model is used to simulate the steady creep behavior of mudstone, and the nonlinear viscoplastic strain-softening model is used to simulate the accelerated creep behavior and post-peak strength attenuation behavior. The experimental results show that the viscoplastic parameters and post-peak softening parameters of mudstone are highly sensitive to confining pressure and exhibit nonlinear characteristics. The accelerated creep curve obtained by the numerical calculation is consistent with the experiments, which verifies the model reliability. We use the NBSS and nonlinear Burgers Mohr-Coulomb (NBMC) models to calculate the plastic zone distribution characteristics and deformation law. The distribution of the plastic zone calculated by the NBSS model is larger with more localized fractures. The NBSS model is useful for studying the evolution of stress and displacement fields of complex surrounding rock mass, which provides important theoretical guidelines for the support design and stability analysis of soft rock tunnel engineering.

Iptek Bagi Masyarakat: Sumur Resapan Desa Tanjung Gusta untuk Pengendali Banjir

2017 ◽  
Vol 1 (2) ◽  
pp. 44
Author(s):  
Fahrizal Zulkarnain
Keyword(s):  
Ground Water ◽  
Water Surface ◽  
Soil Layer ◽  
Drainage System ◽  
Water Infiltration ◽  
Water Volume ◽  
Residential Areas ◽  
Deep Soil ◽  
Short Time ◽  
The Impact

The use of infiltration well as a flood controller can also be useful in anticipation of the decrease in the watertable in the dry season. Infiltration well also serves to maintain the ground water level, decrease groundwatercontamination, reduce groundwater degradation, help to overcome the lack of clean water, maintain water balance in thesoil, reduce the stagnant residential areas due to poorly functioning drainage system, and reduce soil erosion in someplaces due to lack of water infiltration into the soil. The water from the infiltration well will lead to a deep soil layer sothat the decrease of the ground water surface will not occur in a short time due to its existence. Community participationin implementing infiltration wells is very functional and will significantly reduce the impact of floods. In general, infiltration wells that can help reduce surface water are those that have a well dimension of 2 x 2 x 2 meters, thusaccommodating the water volume of  8 m3 expected to be impregnated into the ground as soon as possible to cope with flooding

Sign in / Sign up

Export Citation Format

Share Document