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Obudowa stosowana w wyrobiskach przygotowawczych w zagłębiu Cam Pha w Wietnamie

Van Hoang Do

Przegląd Górniczy

2020

T. 76, nr 7

18--25

Zagłębie Cam Pha to największe zagłębie węglowe w Wietnamie, zlokalizowane w prowincji Quang Ninh, z sześcioma dużymi kopalniami podziemnymi: Khe Cham, Mong Duong, Thong Nhat, Duong Huy, Ha Long i Quang Hanh. Obecnie, złoże antracytu eksploatowane jest przeważnie metodą podziemną w Quang Ninh. Wydobycie węgla z podziemnych kopalń w rejonie Quang Ninh stopniowo wzrasta i według przewidywań będzie stanowić około 75 % całkowitej produkcji węgla w 2030 roku. Dotychczas, długość drążonych rocznie wyrobisk przygotowawczych w kopalniach podziemnych w zagłębiu Cam Pha wynosi około 90÷150 km, z czego 84% jest zabezpieczonych stalową obudową odrzwiową podatną wykonaną głównie z kształtownika typu SWP. Jednocześnie w ostatnich latach średnia długość wyrobisk przebudowanych w kopalniach w zagłębiu Cam Pha stanowi około 30% długości wyrobisk drążonych. Głównie spowodowane to jest utratą stateczności obudowy. Pociąga to za sobą znaczne koszty materiałowe oraz koszty robocizny wymiany uszkodzonych elementów, a także zakłóca ciągłość prac górniczych. Prowadzone są prace w kierunku zidentyfikowania przyczyny utraty stateczności wyrobisk korytarzowych oraz oceny możliwości zastosowania innych typów obudów odrzwiowych, dostosowanych do warunków geologiczno-górniczych zagłębia Cam Pha. W artykule przedstawiono także obecnie stosowaną obudowę wyrobisk przygotowawczych w kopalniach w Wietnamie.

Cam Pha is the largest coal basin of Vietnam, located in the Quang Ninh province, with 6 underground mines: Khe Cham, Mong Duong, Thong Nhat, Duong Huy, Ha Long and Quang Hanh. Curently, coal is exploited mainly by underground method w Quang Ninh. Coal production from the underground mines is gradually increasing and it is expected to constitute about 75% of the country’s total coal production in 2030. This involves an increase in the number and length of underground workings. So far, the yearly length of underground workings driven in underground mines in the Cam Pha basin is roughly 90÷150 km. About 84 % of these underground workings are supported by the steel arch support made of SWP profile. In addition, the average length of repaired underground workings in the Cam Pha basin constitutes approximately 30% of the total length driven. The main cause was reported is loss of underground workings stability. This requires significant material and labour costs as well as the cost of replacing damaged elements. Additionally, it disturbs the continuity of the mining operations. Studies have been carried out to identify the failures in the underground workings and assess possibility of application of different types of steel arch support for geo-mining conditions in the Cam Pha coal basin. This paper also presents actual support that applied in the underground workings in Vietnamese coal mines.

Analysis of behaviour of the steel arch support in the geological and mining conditions of the Cam Pha coal basin, Vietnam

Nguyen Phu Minh Vuong, Rotkegel Marek, Van Hoang Do

Archives of Mining Sciences

2020

Vol. 65, no. 3

551--567

In recent years, the Vietnamese coal mining industry has observed a dynamic increase in both its production and efficiency. In Vietnam, the most precious type of coal is anthracite, which is found in the Quang Ninh province. Industrial anthracite deposits are estimated to be over 2 billion Mg. At present, coal deposits are extracted mostly by the underground method. Coal production is gradually increasing in the underground mines in the Quang Ninh area and it is expected to constitute about 75% of the country’s total coal production in 2030. This involves an increase in the number and length of underground workings. Cam Pha is the largest coal basin of Vietnam, located in the Quang Ninh province. So far, the yearly length of underground workings driven in underground mines in the Cam Pha basin is roughly 90÷150 km. About 84 % of these underground workings are supported by the steel arch support made of SWP profile. A similar situation can be observed in Russia, Ukraine, China, India and Turkey. In addition, the average length of repaired underground workings in the Cam Pha basin constitutes approximately 30% of the total length driven . The main cause was reported is loss of underground workings stability. This requires significant material and labour costs as well as the cost of replacing damaged elements. Addi-tionally, it disturbs the continuity of the mining operations.This article presents the results of the numerical modelling of the rock mass around underground wor-kings driven in typical geo-mining conditions for underground coal mines in the Cam Pha basin, supported by the steel arch support made of SWP and V profiles. As a result of the conducted analyses, the range of failure zone of the rock mass around underground workings and the distribution of reduced stress in the steel arch support elements were determined. The effort states of the steel arch support made of SWP22 profile and V21 profile were compared. The simulations considered different inclinations angle of coal seam, following the structure of the rock mass in the Cam Pha basin. The analysis was carried out using the based-finite difference method code, FLAC2D. Based on the obtained results, actions for improving the stability of underground workings driven in the underground mines of the Cam Pha basin were proposed.