Large Deformation Characteristics of Surrounding Rock and Support Technology of Shallow-Buried Soft Rock Roadway: A Case Study

The coal resources in the coal-rich area of western China are mostly located in the late diagenetic Cretaceous and Jurassic strata. In this paper, a study on the support of soft rock roadways was carried out in the background of the soft rock track roadway in the Jiebangou coal mine. The field investigation showed that the surrounding rocks of the roadway were weak, soft, and broken, and the surrounding rocks were cemented, with the roadway local deformation exceeding 1 m. The borehole television results showed that the surrounding rocks were mainly weak sandy mudstone and yellow mudstone. The average uniaxial compressive strength of the surrounding rock was 15.49 MPa. The roadway is a shallow buried soft rock roadway; site investigation revealed that the original U-shaped steel shed had an extremely low resistance to slip, the filling body behind the U-shaped steel shed fell off, the interaction between the U-shaped steel shed and the surrounding rock was poor, the U-shaped steel shed could not provide sufficient timely support resistance, and the bearing capacity of the U-shaped steel shed was far from consideration. The floor was not effectively supported. The floor had different degrees of the bottom drum, and frequent undercover caused new stress disturbances, which loosened the bottom corners of both rock types and made the shed legs move continuously inward, reducing the bearing capacity and actual support resistance of the bracket. Numerical calculations were performed to study the deformation characteristics of the surrounding rock of the tunnel and the yielding damage characteristics of the brace. The results showed that the current U-shack support strength was insufficient, the two sides were deformed by 950 mm, the bottom of the roadway bulged by 540 mm, and the surrounding rock was mainly shear damaged. The fall of the filler behind the shed caused damage to the U-shaped steel shed spire. Through site investigation results and numerical calculations, the deformation and damage characteristics of the soft rock roadway and its damage causes were analyzed, and the support technology system of ‘strengthening support for weak structural parts’ was proposed. This improved the mechanical properties of the weak structural support body, the stress state of the local surrounding rock, and the bearing capacity of the support structure, and effectively controlled the deformation, damage, and instability of the surrounding rock of the roadway, and deformation, damage, and destabilization of the roadway, thereby achieving overall stability for the surrounding rock of the roadway.

Surrounding Rock Control Technology When the Longwall Face Crosses Abandoned Roadways: A Case Study

When a working face is crossing the abandoned roadways, problems such as roof subsidence, rock fracture, and instability will occur, resulting in widespread roof fall and rib spalling, which seriously affect safe and efficient mining on the working face. In this paper, the no. 23 coal pillar working face of Juji coal mine is taken as the engineering background, a mechanical model of crossing the abandoned roadways is constructed aimed at the problem of the working face crossing the abandoned roadway group, the collapse of the abandoned roadway roof is analyzed, a scheme of crossing the abandoned roadways is designed, and the development law of the stress and plastic zone after the reinforcement scheme is stimulated and analyzed. The results show that when the working face advances to the abandoned roadway, key block B crosses the abandoned roadway and the solid coal to form a “cross-roadway long key block.” It is calculated that the minimum support resistance required for the abandoned roadway is 6700 kN. Based on the results of numerical comparison, it is concluded that filling wood pile when the working face passes through the roof abandoned roadway and adding anchor cables for reinforcement support when the working face crosses the coal seam abandoned roadway effectively reduce the stress concentration of surrounding rocks, decrease the development of the plastic zone, and achieve safe and efficient mining when the working face crosses the abandoned roadways.

Application of the Ultimate Hanging Arch Length of the Layered Roof with Anchors and the Gob-Side Entry Retaining

The gob-side entry retaining plays an important role in improving working face ventilation, alleviating working face connection, and increasing mining revenue. According to the characteristics of the crossheading roof at the 2103 working face of a mine in Shanxi, a structural mechanics model of the roof was established to derive the theoretical formulae for the ultimate hanging arch length of the layered roof with anchors and the initial support resistance of the entry-side support. The influence factors of the ultimate hanging arch length were evaluated using local sensitivity analysis. Based on the theoretical study, the work proposed the collaborative support technology of the crossheading, collaborative support at the 2103 working face. The results showed that the ultimate hanging arch length was most influenced by the width of the plastic zone, followed by the width of the roadway, supporting strength, anchoring strength, layered thickness, and mining depth, while the ultimate tensile strength had little influence. The initial support resistance of the entry-side supports was closely related to the ultimate hanging arch length and the process of gob-side entry retaining. The improved entry-retaining supporting process could control the sharp surface convergence of the surrounding rocks of the entry retaining, the sinkage of the roof of the entry-retaining section was controlled below 100 mm, and that of the advanced section was controlled below 50 mm. The stability of the supports next to the entry is improved, and the needs of the site project are met.

TECHNICAL ANALYSIS OF FOOD AND BEVERAGE SECTOR STOCKS IN JII

ABSTRAK Investasi merupakan upaya menanamkan dana untuk dikembangkan dalam jangka waktu yang telah ditentukan untuk mendapatkan keuntungan. Investasi bisa dilakukan melalui sektor rill, maupun non rill. Pada penelitian ini akan membahas investasi sektor non rill terutama di pasar modal yang sudah jelas return dan kemanannya, yang akan berfokus pada saham. JII (Jakata Islmaic Index) adalah 30 saham syariah yang paling liquid di BEI. Terdapat empat saham sektor food and beverage, seperti ICBP, INDF, JPFA, dan UNVR. analisis teknikal menggunakan historis harga dari suatu perusahaan atau saham itu sendiri, yang berasumsi bahwa itu dapat merefleksikan harga dimasa depan, biasanya yang menggunakan analisis teknikal adalah investor jangka pendek, jangka pendek disini adalah mereka para tradder yang aktif berdagang saham. Grafik adalah indikator utama untuk analisis teknikal, terutama grafik candlestick karena grafik ini mampu menampilkan pergerakan harga secara menyeluruh. Resistance adalah keadaan dimana harga sulit bergerak lebih tinggi, sedangkan support adalah kebalikannya yaitu harga sudah sulit untuk lebih rendah, kedua garis batas ini digunakan sebagai pengambil keputusan dalam analisis teknikal. Pendekatan yang biasa dilakukan adalah menggunakan pendekatan fibonacci dan umunya dibantu lagi oleh stochastic oscillator untuk menunjukan posisi closing relatif pada suatu periode. Saham ICBP dilihat dari hasil fibonacci dan indikator stochastic oscillator yang menunjukan saham ICBP mendekati resistance dan stochastic oscillator berada pada titik 70 normal zone tetapi mulai mendekati zona overbought yaitu melewati titik 80. Kata kunci : : Investasi, Analisis Teknikal, Fibonnaci, Support, Resistance, Stochastic Oscillato

EXPRESS: Identity Management as a Coping Strategy for Stigmatization: The Case of Indian Sex Workers in a Libidinal Market

Poor women can face stigmas about indolence, moral turpitude, and substance abuse. This stigmatized condition includes female sex workers, who live and work in situations that exacerbate impoverishment and bring societal exclusion and shame. We situate our arguments at the nexus of poverty and stigma and examine the value of identity formation and reformation in the context of female sex workers in India. These women face restrictions to meet basic needs and remain in the profession despite significant challenges. Our study reveals five identity pathways in their collective consciousness: protector, sacred, commoditized, provider, and eudaimonic/self-acceptance. They come together as themes that reflect these women's lived experiences who were forced to endure systemic violence in relative silence. We use and advance arguments provided by Hill, Ozanne, and Viswanathan and their various colleagues to frame our current understanding of their plight. We contribute to theory by revealing that these identities have positive consequences for personal reconfiguration under conditions of vulnerability. Finally, our results indicate that public policy should recognize the value of self-identities that support resistance in a marginalized marketplace. Sensitizing stakeholders, including policy makers, to destigmatization may also help sex workers gain the courage of their convictions to leave the profession.

Immuno-Boosters as Health Accelerants to Tackle Viral Infections

The immune framework is one of nature's most entrancing creations. It is an astonishing assurance system intended to protect us against many microorganisms, infections, organisms, poisons and parasites. The immune framework is intricate. It is comprised of a few sorts of cells and proteins that have various tasks to take care of in battling against unfamiliar trespassers. On the off chance that the immune framework is working appropriately, we are shielded from perils brought about by organisms. If not, we endure disorder and illness. It is conceivable to intercede in this cycle and make our immune framework more grounded utilizing immune sponsors. Immune supporters work from various perspectives. They increment the number of white platelets in the immune framework armed force, train them to battle against microorganisms causing illnesses. This audit article gives a general view about some significant way of life and food propensities that support resistance.

Roof structure of shallow coal seam group mining in Western China

In order to realize roof control of shallow coal seam group mining in Western China, combining with engineering statistics, physical simulation and theoretical analysis, the roof weighting characteristics during lower coal seam mining were revealed, and the classification of shallow coal seam group was proposed. Based on this, mechanical models of roof structure were set up, and the calculation method of support resistance was determined. The results show that the roof weighting is closely related to the interburden thickness and the mining height of lower coal seam, considering the ratio of interburden thickness to the mining height, as well as the key stratum structure, the classification of shallow coal seam group was put forward. The first type is shallow coal seam group with no key stratum (SCSG-No), its roof pressure is mainly affected by caving roof of upper coal seam, and the interburden roof forms slanting pillar-beam structure. The second type is shallow coal seam group with single key stratum (SCSG-S), interburden roof represents step voussoir beam structure. The third type is shallow coal seam group with double key strata (SCSG-D), interburden roof can form double key strata structure, the lower key stratum forms slanting step voussoir beam structure, while the upper key stratum forms voussoir beam structure, besides, longwall face represents large—small periodic weighting. Through establishing the roof structure models, the calculation formulas of support resistance were determined, it can provide basis for roof control and promote safe mining in Western China.

Stability Analysis and Control Technology of Gob-Side Entry Retaining with Double Roadways by Filling with High-Water Material in Gently inclined Coal Seam

Roadside filling body in traditional gob-side entry retaining (GER) has several shortcomings such as the insufficient support resistance, the inability to adapt to the deformation of surrounding rock and isolate the goaf effectively. Taking the GER with double roadways by filling with 1.8-m-wide high-water material in gently inclined coal seam of Zuozegou mine as a project case, the mechanical model of GER with double roadways in the gently inclined coal seam is constructed, and the reasonable width of the filling body of GER is verified by combining with the peak strength of high-water material. The FLAC3D numerical simulation method is used to study the distribution characteristics of stress and plastic zone of GER after being affected by the mining disturbance, and the failure range of surrounding rock of GER with double roadways is obtained. Based on this, a coupling control technology named anchor cables and bolts in the roof and solid coal + single props in entry-in support and goaf side of the outer roadway + anchor bolts in roadside high-water material + short anchor cables below the filling body is proposed and conducted in industrial test. Through the coupling methods of arranging borehole peeping and observing the convergences of surrounding rock, the stability of GER with double roadways is analyzed. The results show that GER with double roadways by filling with 1.8-m-wide high-water material has good control effect. The above research has played an active role in promoting the application of high-water material in roadside filling of GER.

Three-Dimensional Physical Simulation and Control Technology of Roof Movement Characteristics in Non-Pillar Gob-Side Entry Retaining by Roof Cutting

An overlying rock structure plays a key role in controlling the roof deformation of nonpillar gob-side entry retaining by roof cutting. On the bases of the actual geological conditions of II 632 Haulage Roadway at the Hengyuan coal mine, a similar three-dimensional simulation experiment of roof precutting is conducted. Thereafter, the caving characteristics and migration law of the roof strata in the strike and dip directions are obtained. Moreover, the roof of the retained roadway and key strata of the goaf can form a hinge structure of the key blocks. By monitoring the deformation of the surrounding rock and stress distribution of the roof, the skew deformation characteristics of roadway roof are obtained. By observing the borehole peeping technology, the roof subsidence near the goaf is determined to be greater than that of the solid coal side, and the roof subsidence of the gob-side entry retained by roof cutting is greater than that of the floor heave and two sides approaching. Results of the three-dimensional similar simulation experiment indicate that the mechanical structure model of the key block of the retained roadway roof is constructed, and the mechanical analytical solution of the required support resistance of the retained roadway roof is obtained. This study proposes the constant resistance and large deformation anchor cable reinforcement support method to control the roof deformation of the retaining roadway. Through engineering application, the maximum value of the roof and floor movement of the retained roadway is stable at approximately 650 mm. The retained roadway can meet the demand of the next mining face.

Study on Surrounding Rock Structure Evolution Characteristics and Roof Control Techniques of the Retained Roadway Formed by Roof Cutting in Inclined Coal Seams

To control the roof during gob-side entry retaining by roof cutting in inclined coal seams, the retained gob-side roadway is zoned based on the mechanical principle and technological process of no-pillar mining with gob-entry retention. A simplified mechanical model for surrounding rocks in different subzones was established by using theoretical analysis and numerical simulation to attain the demand for the support resistance and deformation of the roof in different subzones. According to load and deformation characteristics of the roof and mechanical characteristics of NPR cables, single props, and a sliding-type gangue-retaining structure formed by U-shaped steel inserts, the supporting systems for roadways in different subzones and the constitutive model thereof were established. On this basis, the action of the supporting system was analysed and a field test was performed. The results show that the supporting system undergoes three stages of behaviour, i.e., pressure growth, yielding under constant pressure, and stabilisation during whole entry retention. It can guarantee the collaborative deformation of the supporting systems with the roof on the premise of constant support resistance, thus satisfying the requirement for roadway protection. The roadway 150 m back from the working face is stable, and the final convergence between the roof and floor of the retained entry is 257 mm, showing a favourable entry-retention effect.