scholarly journals Research on the Reuse of Discharged Soil from EBP Shield Tunnels in Synchronous Grouting Material

2022 ◽  
Vol 2022 ◽  
pp. 1-15
Author(s):  
Guijun Luo ◽  
Chao Xiao ◽  
Yuan Liu ◽  
Kejun Feng ◽  
Qingguo Ren
Keyword(s):  
Engineering Application ◽  
Fine Sand ◽  
Surface Settlement ◽  
Practical Significance ◽  
Filling Rate ◽  
Performance Requirements ◽  
Grouting Pressure ◽  
Grouting Material ◽  
Grouting Materials ◽  
Epb Shield

Great practical significance and engineering application value can be achieved when the large amount of discharged soil produced by EPB shield tunnels is recycled and comprehensively utilized. As one of the key processes of shield construction, synchronous grouting needs a large amount of bentonite, cement, fly ash, sand, and other materials. The research on the reuse of shield muck as synchronous grouting material is carried out based on Zhengzhou subway project. The physical properties and phase of the discharged soil from EPB shield tunnels are studied by using laboratory tests and XRD. The statistics show that the shield muck meets the performance requirements of bentonite and fine sand in synchronous grouting materials. The optimal grout ratio of the reused muck is obtained based on the optimization idea of multiobjective programming by MATLAB. Considering the combined effect of seepage field, stress field, and the timeliness of the grout, the influences of grouting pressure and the filling rate of synchronous grouting on surface settlement, plastic zone of strata, and segment deformation are analyzed by using finite difference method. The results prove that the surface settlement and segment deformation can be better controlled when the grouting pressure is at 0.18 MPa and the grouting rate is at 120%–150%.

scholarly journals Polyurethane/Red Mud Composites with Flexibility, Stretchability, and Flame Retardancy for Grouting

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 906 ◽  
Author(s):  
Chunjing Zhang ◽  
Bo Shuai ◽  
Xuefeng Zhang ◽  
Xinxin Hu ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Polyethylene Glycol ◽  
Flame Retardancy ◽  
Red Mud ◽  
Three Dimensional ◽  
Engineering Application ◽  
Synergistic Interactions ◽  
Grouting Material ◽  
Dimensional Network ◽  
Grouting Materials ◽  
Inorganic Composite

Flexibility, stretchability, and flame retardancy are of ever increasing importance in constructing grouting materials. Herein, a simple and effective strategy to make organic-inorganic composite grouting material in a “flexible, stretchable, and flame retardant” way was based on the excellent synergistic interactions among polyurethane prepolymer, red mud, polyethylene glycol, and trimethylolpropane. The resultant polyurethane/red mud composite grouting material with three-dimensional network structure presented a favorable flexibility, desirable compressive strength of 29.2 MPa at 50% compression state, and a good elongation at 15.1%. The grouting material was mainly composed of amorphous polyurethane and crystalline red mud, and its probable formation mechanism was reaction of prepolymer with H2O, polyethylene glycol and trimethylolpropane under vigorous stirring in the presence of catalyst. Furthermore, the grouting material possessed favorable thermal stability, flame retardancy and repairment performance for roadway cracks. This work may open a simple and convenient avenue for the massive engineering application of red mud and preparation of flexible organic-inorganic hybrid grouting material.

Study on Microfine Cement Grouting Material for Silty Fine Sand Stratum

2013 ◽  
Vol 838-841 ◽  
pp. 1457-1462
Author(s):  
Chun Lei Xia ◽  
Ying Ye ◽  
Guan Ming Wang ◽  
Li Cui
Keyword(s):  
Portland Cement ◽  
Particle Diameter ◽  
Fine Sand ◽  
Cement Grouting ◽  
Grouting Material ◽  
Soluble Glass ◽  
Microfine Cement ◽  
Sand Flow ◽  
Sand Stratum ◽  
Grouting Materials

Silty fine sand is the second smallest sand with a particle diameter ranging from 0.0625 to 0.120 mm.This kind of sand exists in a large amount in Beijing subway excavation project. Due to the poor self-stabilization of this stratum,seeping , sand flow and collapse take place frequently. Grouting materials such as Portland cement and soluble glass (also called sodium silicate) are employed in most of excavation projects to reinforce this sand stratum. However, the reinforcement is not effective, leading to a large amount of accidents in the process of construction. The reason may be attributed to the fact that Portland cement is unable to penetrate into the stratum and the strength of soluble glass (0.6MPa) is too weak to resist the stratum pressure. To solve this problem, a modified microfine cement grouting material able to penetrate into silty fine sand stratum is developed in this paper. A combination of suspension and diluent is used to increase the penetration extension of the grouts,and the experimental results reveal that the addition of the mixture of suspension and diluent in microfine cement grouting materials improves the penetration property substantially.

scholarly journals Experimental Study on the Influence of PVA Content on the Performance of Grouting Material in Deep Stope

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Bin Liu ◽  
Liming Yin ◽  
Juntao Chen ◽  
Ming Li ◽  
Daozeng Tang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Setting Time ◽  
Practical Significance ◽  
Peak Period ◽  
Grouting Material ◽  
Coupling Characteristics ◽  
Grouting Materials ◽  
And Control ◽  
Water Hazards

Based on laboratory experiments, the paper researches the effect of polyvinyl alcohol (PVA) content on the performance of fly ash-based cement grouting materials. The test results show that the addition of PVA has limited effect on the initial and final setting time and brings a certain but minor delay on the appearance of the hydration peak period. It enhances cement hydration during the hydration slow down period. The impermeability of PVA to the grouting material is obviously improved, and it increases with the growing amount of PVA content. PVA improves the flexural strength and compressive strength of the sample block to varying degrees, and the improvement on flexural strength is more obvious than that on the compressive strength. It has a significant effect on the mechanical properties of the grouting material and can effectively improve the rock mass’s hydraulic coupling characteristics. It also has great application value and practical significance for the prevention and control of water hazards in deep coal stopes.

Research on Ground Settlement due to EPB Shield

2011 ◽  
Vol 105-107 ◽  
pp. 1276-1279
Author(s):  
Zhi Gang Yan
Keyword(s):  
Numerical Experiments ◽  
Three Dimensional ◽  
Surface Displacement ◽  
Surface Settlement ◽  
Ground Settlement ◽  
Balance Condition ◽  
Grouting Pressure ◽  
Working Face ◽  
Epb Shield

The surface settlement is affected by many factors due to EPB shield. This paper takes the shield construction of Guangzhou Metro Line 5 as an example, carries out three dimensional numerical experiments on the ground settlement rule. The result indicates that soil warehouse pressure and the efficiency of grouting is important factors of the surface displacement. To increase grouting pressure and shorten the grouting time can reduced the ground settlement in effective. With the increase the soil warehouse pressure, the settlement behind the working face is reduced and the front working face is increased. When the soil warehouse pressure is at the over balance condition, the raising ground is increased and the settlement is reduced. The value of settlement is much larger than the value of raising. So to increase the soil warehouse pressure is another effective method to reduced the ground settlement on the premise that the front soil body of shield does not be destroy.

scholarly journals Development of Modified Grouting Material and Its Application in Roadway Repair Engineering

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Yang Yu ◽  
Zhengyuan Qin ◽  
Xiangyu Wang ◽  
Lianying Zhang ◽  
Dingchao Chen ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Surrounding Rock ◽  
Engineering Practice ◽  
Mass Ratio ◽  
Control Effect ◽  
Grouting Pressure ◽  
Grouting Material ◽  
Wide Range ◽  
Grouting Reinforcement ◽  
Grouting Materials

It is very extraordinary for the success of coal mine roadway grouting with the following factors of high early strength, good fluidity, and convenient pumping, but the existing grouting materials make it difficult to achieve the above characteristics at the same time. Therefore, a modified grouting material is developed, which is composed of two kinds of dry materials A and B, which are mixed with water and in equal amounts. The physical and mechanical properties of modified grouting materials under different ratios were tested by laboratory orthogonal test, and the optimal ratio of grouting materials and additives was obtained: (1) the water-cement ratio is 0.8 : 1; (2) base material: the mass ratio of cement, fly ash, bentonite, and water is 1 : 0.3 : 0.1 : 1.44; (3) admixture: the mass ratio of water reducer C, accelerator D, and retarder E is 1.5% : 0.05% : 0.3%. The basic properties of the modified grouting materials were studied from the aspects of slurry flow state, diffusion range, and grouting parameters by using the numerical simulation method, and the reinforcement mechanism of slurry to the broken surrounding rock properties of the roadway was revealed: (1) the grouting pressure is the main factor affecting the slurry diffusion radius; (2) the mechanical properties of the roadway surrounding rock are improved, the plastic zone and deformation of surrounding rock are reduced, and the active support function of the anchor and cable is enhanced through grouting reinforcement; (3) the control effect of the roadway is improved, and the balanced bearing with anchorage structure of the roadway surrounding rock is realized through grouting reinforcement. On this basis, the modified grouting material is applied to roadway repair and reinforcement engineering practice. The field monitoring data show that the production practices were guided by roadway repair and reinforcement technology with the modified grouting material, as the core of the roadway surrounding rock control effect is good, and the modified grouting material has a wide range of application prospects.

Researching on a New Grouting Material and its Engineering Application

2015 ◽  
Vol 1088 ◽  
pp. 544-548 ◽  
Author(s):  
Jing Lei Dou ◽  
Jing Feng Dou ◽  
Yu Juan Guo
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Coal Mine ◽  
Engineering Application ◽  
The Body ◽  
Gas Explosion ◽  
Cement Material ◽  
Grouting Material ◽  
Grouting Materials

Water-irruption is the second to gas explosion of major security problems in coal mine. The grouting material is composed of fly ash and montmorillonite separately according to a certain proportion with pure cement material. On the site grouting test and compare the compressive strength of the stones of the body and the size of the diffusion radius, and compare the grouting materials with pure cement materials. Through the comparative and analysis, the reasonable grouting materials are choosen.

The Regression Prediction Analysis of Grouting Concretion Stone’s Strength Based on SVR

2013 ◽  
Vol 859 ◽  
pp. 171-176 ◽  
Author(s):  
Jin Sheng Lei ◽  
Jian Fei Chen ◽  
Xue Ting Cao ◽  
Qian Feng Wang
Keyword(s):  
Support Vector Machines ◽  
Support Vector ◽  
Grouting Pressure ◽  
Grouting Material ◽  
Strength Based ◽  
Vector Machines ◽  
Gravel Soil ◽  
Strength Tests ◽  
Grouting Materials ◽  
The Relationship

Cement-based grouting material is used for the grouting of gravel soil, and do compressive strength tests for the grouting concretion stones. Use the method of support vector machines for regression (SVR) to deal with the test data and predict the grouting concretion stones strength. Specific methods are as follows: randomly select 20 groups of the specimens for training, the remaining specimens for predicting, and then establish the relationship between the performance of soil body medium, grouting materials, grouting pressure and strength of concretion stones strength. The research results show that the support vector machines method can judge the sensitivity to impact indicators of grouting stones strength, and predict and analysis the grouting stones strength under multiple factors.

Study of Rheological Properties of Carbon Nanotube-Reinforced Ultrafine Cement Grouting Materials

2021 ◽  
pp. 1-44
Author(s):  
Yunxiao Liu ◽  
Jiahang Zhang ◽  
Yinyin Chi
Keyword(s):  
Carbon Nanotubes ◽  
Rheological Properties ◽  
Polyvinyl Pyrrolidone ◽  
Cement Grouting ◽  
Grouting Material ◽  
Multi Walled Carbon Nanotubes ◽  
Different Diameters ◽  
Grouting Materials ◽  
Walled Carbon Nanotubes ◽  
Ultrafine Cement

In this study, three different diameters of multi-walled carbon nanotubes (MWCNTs) dispersed by polyvinyl pyrrolidone (PVP) were used to reinforce superfine cement grouting materials. The effect of MWCNTs and polyvinyl pyrrolidone (PVP) on the rheological properties of grouting material were accordingly studied. It was found that the yield stress (τ0) and plastic viscosity (η) were slightly decreased when PVP content was low and increased when the PVP content increased. The effect of MWCNT diameter on τ0 was not found to be clear but was more significant on η. The smaller MWCNT diameter was, the more quickly η increase. It was also found that the thixotropic ring area was increased as the MWCNTs content increased. The addition of PVP and MWCNTs caused an increase in the number of entanglement points in different scales, which was the main reason for the viscosity and thixotropy increase. Therefore, the rheological properties of superfine cement grouting material should be adjusted when MWCNTs were added as a reinforcing component. Due to the wrapping of PVP on cement particles which isolates the contacting part between the water and the cement particles, it slows down the cement's hydration rate thus slows down the fluidity loss of the slurry.

scholarly journals Manycore Performance-Portability: Kokkos Multidimensional Array Library

2012 ◽  
Vol 20 (2) ◽  
pp. 89-114 ◽  
Author(s):  
H. Carter Edwards ◽  
Daniel Sunderland ◽  
Vicki Porter ◽  
Chris Amsler ◽  
Sam Mish
Keyword(s):  
Programming Model ◽  
Engineering Application ◽  
Data Access ◽  
Memory Space ◽  
Performance Requirements ◽  
Application Programming ◽  
Multidimensional Array ◽  
And Performance ◽  
Data Access Patterns ◽  
Access Patterns

Large, complex scientific and engineering application code have a significant investment in computational kernels to implement their mathematical models. Porting these computational kernels to the collection of modern manycore accelerator devices is a major challenge in that these devices have diverse programming models, application programming interfaces (APIs), and performance requirements. The Kokkos Array programming model provides library-based approach to implement computational kernels that are performance-portable to CPU-multicore and GPGPU accelerator devices. This programming model is based upon three fundamental concepts: (1) manycore compute devices each with its own memory space, (2) data parallel kernels and (3) multidimensional arrays. Kernel execution performance is, especially for NVIDIA® devices, extremely dependent on data access patterns. Optimal data access pattern can be different for different manycore devices – potentially leading to different implementations of computational kernels specialized for different devices. The Kokkos Array programming model supports performance-portable kernels by (1) separating data access patterns from computational kernels through a multidimensional array API and (2) introduce device-specific data access mappings when a kernel is compiled. An implementation of Kokkos Array is available through Trilinos [Trilinos website, http://trilinos.sandia.gov/, August 2011].

scholarly journals The Analysis, Discussion and Suggestions for the Mesh Reinforcement Technique of Polymer Mortar Wire Rope

2012 ◽  
Vol 5 ◽  
pp. 271-276
Author(s):  
Shu Ren Zhang ◽  
Zhong Long Li
Keyword(s):  
Engineering Application ◽  
Wire Rope ◽  
Practical Significance ◽  
Strengthening Effect ◽  
Technical Standards ◽  
Healthy Development ◽  
Mesh Reinforcement ◽  
Polymer Mortar ◽  
The Difference ◽  
Correct Understanding

The mesh reinforcement technique of polymer mortar wire rope is a new reinforcement technique used more in the domestic fittest reinforcement project recent years. Recently, there is no unified technical standards, the detailed practice is not same in practical work. There are big differences among the reinforcement effects. The key issue of wire rope is whether add prestressed or not. If add, how much should be prestressed? The difference of the actual practice and reinforcement effect reflects the understanding gap polymer mortar wire rope of mesh reinforcement technique action principle of the designer. A correct understanding of polymer mortar wire rope of mesh reinforcement technique the mechanism and the objective analysis strengthening effect and actively explore research in engineering application problems have a practical significance to promote the healthy development of the structure strengthening technology.

Sign in / Sign up

Export Citation Format

Share Document