Stability Analysis of Surrounding Rock of Large Section Ultradeep Shaft Wall

In order to study the stability of deep surrounding rock during the excavation of new main shaft in Xincheng gold mine, a construction method suitable for large section ultradeep shaft is proposed. A series of analyses were carried out in this study, including the in situ stress test, stress response of surrounding rock disturbance, deformation and failure characteristics, and numerical simulation. Based on the above analysis, the stability control method of surrounding rock in the process of deep excavation of the new main shaft is proposed. The results show that (1) the maximum principal stress of deep surrounding rock of new main shaft is horizontal stress, and the surrounding rock of the shaft has strong rock burst tendency after excavation; (2) the influence range of the deep shaft excavation disturbance is 6.4 times the shaft radius, in which the temporary support should be strengthened to avoid the influence of excavation disturbance on the stability of shaft wall rock; (3) the failure shape of surrounding rock of the deep shaft excavation was “ear” failure, and the failure depth was not more than 2.5 m; (4) after replacing the original “one-excavation and one-masonry” construction with “three-excavation and one-masonry” construction, the temporary support span of the main shaft was adjusted to 12 m, which can make the subsequent concrete shaft wall in the state of “no pressure bearing or slow low pressure bearing,” and the lining compressive safety coefficient was increased to 1.98, which meets the safety requirements.

On preventing the dripping effect of overhang constraints in topology optimization for additive manufacturing

This article falls within the scope of topology optimization for Additive Manufacturing processes and proposes an alternative strategy to prevent the phenomenon known as the Dripping Effect. The Dripping Effect is when an overhang constraint is imposed on topology optimization processes for Additive Manufacturing and is defined as the formation of oscillatory contour trends within the prescribed threshold angle. Although these drop-like formations constitute local minimizers of the constraint function, they do not provide a printable feature, and, therefore, they neither eliminate the need to form temporary support structures. So far, there has been no general agreement on how to prevent the Dripping Effect, so this work aims to introduce a strategy that effectively prevents it, and that at the same time may be easy to extrapolate to other types of geometric overhang restrictions. This paper provides a study of the origin of the Dripping Effect and gives detailed instructions on how the proposed prevention strategy is applied. In addition, several benchmark examples where the Dripping Effect is prevented are shown.

Development of plastic abilities of children-autistics by means of modern-dance in the conditions of modern cultural and artistic practices

The purpose of the article is to determine the methods of developing the creative abilities of autistic children by modern choreography. Methodology: in our work, we used systematic and comparative methods, as well as problem and analytical analysis of the literature to study methods of developing autistic children through art therapy and choreography, to improve their plastic capabilities and study the latest trends in art and psychology. Scientific novelty. The question of the development of creative abilities of autistic children by art therapy has already been studied in modern literature, but the novelty of the research it’s the first attempt to determine methods of developing plastic abilities of children with autism by means of modern dance. Due to the research, we have identified methods for developing the creative abilities of autistic children by means of modern choreography, in particular - modern dance. On the one hand, the focus of modern pedagogy is on people with special needs who receive additional permanent or temporary support in the educational process in order to ensure their right to education. On the other hand, much less importance is given to meeting the needs of children with autism by involving them in modern cultural and artistic practices. Although, in our opinion, it provides much more opportunities for adaptation of people with special needs, the development of their desire for beauty. Our research art and cultural attention have focused on the development of plastic abilities of autistic children by means of modern dance in modern cultural and artistic practices. Conclusions: we determined that it is important to develop the plastic abilities of such children, although it is very difficult to teach such child to dance professionally, it is possible to develop the choreographic grace of movements. In the course of our research, we analyzed the available scientific materials on autism and identified the behavior of autistic children, and explored the possibilities of using modern dance in the development of autistic children as one of the means of developing their creative abilities.

Narrative interviews to assess quality of life in Peritoneal Dialysis

It has been found that people undergoing dialysis have a lower quality of life than the rest of the population. The aim of dialysis is to improve physical health, but also well-being. We were interested in the perception of the quality of life of patients undergoing Peritoneal Dialysis. We used the narrative interview method to collect their feelings, their daily experience, and their impressions about their care. We conducted four in-depth interviews, following the principle of theoretical data saturation, with adults treated at the Hospital of Nice. These interviews indicated that Peritoneal Dialysis rapidly improves physical and emotional health. Patients are satisfied with the technique, which allows them to return to a social, familial, and professional life. However, they regret that it does not relieve them of dietary restrictions, especially on salt. Patients appreciate the temporary support of a private nurse, which is systematically offered by our center at the beginning of treatment. They wish the involvement of peers to benefit from their experience, explanations and practical demonstrations. Quality of life is important to assess when choosing a renal replacement technique. Caregivers have to understand patients’ expectations and wishes in order to guide them towards the dialysis modality that suits their lifestyle and preferences best. This will improve treatment outcomes.

Analysis on the structural type of large-span steel truss bridge specially designed for cables

When the installation of cables and pipelines needs to go across rivers, bridges are usually adopted to support the cables and pipelines for crossing the rivers. The measure can make full use of the space resources and have no effect on the flow pattern of rivers. For this reason, analysis on the structural-type design of a large-span steel truss bridge specially used for cables has been performed. The numerical results indicate that the stayed-cable bridge with steel truss beam and concrete main tower has better performance and improved structural type caparisoned with that of the beam and arch bridges, and the construction of the major beam can be without the temporary support.

The Technique of Thyroid Cartilage Scaffold Support Formation for Extrusion-Based Bioprinting

During biofabrication, a tissue scaffold may require temporary support. The aim of this study was to develop an approach of human thyroid cartilage scaffold temporal support formation. The scaffold 3D-model was based on DICOM images. XY plane projections were used to form scaffold supporting part. To verify the technique, collagen hydrogel was chosen as the main scaffold component. Gelatin was applied for the supporting part. To test the applicability of the approach, a model of thyroid cartilage scaffold with the support was printed. The scaffold corresponded to a given model, although some discrepancy in geometry was observed during verification by computed tomography.

Numerical Analyses on Deformation and Failure Characteristics of Surrounding Rock of Gob-Side Entry Retention by Roof Cutting

Universal distinct element code (UDEC) is a simulation software based on the discrete element method, widely used in geotechnical mining. However, in the UDEC, when simulating large-scale excavation, the subsidence of the fractured zone is almost equal to the mining height, which makes the deformation value calculated in the study of gob-side entry retention too large. To solve this problem, in this paper, the double-yield constitutive model is applied to the whole caving zone to analyze the deformation and failure characteristics of surrounding rock along gob-side entry retaining by roof cutting. The results of the simulation are in good agreement with the result of drilling peeking (drilling observation by borehole televiewer) and field condition (observation and measurement in the field). Finally, by using this numerical method, the effects of roadway width, temporary support, and coal side support on the failure of the roof and the arc coal side are studied.

Numerical Investigation of Innovative Support Frame of Openings in the Segmental Tunnel Lining

Introduction: To supply safety in the tunnels, it is necessary to construct escape routes and emergency exits that are performed by locating cross passages. Methods: These passages connect two tunnels transversely and apply escape routes. Using temporary steel structures to supply the ring stability in practice and reinforced concrete frame to stabilize the ring permanently can be appropriate to form a solid frame that transfers the opened ring's load to the opening surroundings. In this paper, a 3D finite element simulation was performed to analyze the influence of opening construction in the segmental concrete lining and a temporary support system. Using the simulation, stress and deformation distribution of the steel frame, bolts, and segmental lining were obtained. Results: The results show that by increasing the number of bolts from 18 to 30, the induced stress in the steel frame and bolts decreased to 76 and 59 percent, respectively. In addition, the maximum displacement in the segmental lining and the maximum opening value of the joints decline to 62.7 and 75 percent, respectively. Conclusion: Finally, it can be concluded that the steel frame can be used as a temporary support system.