Barrier forming apparatus

A barrier forming apparatus for forming a barrier between an exposed tunnel face and a tunnel boring machine, the barrier being formed by the application to the tunnel face of a barrier mixture comprising two highly reactive first and second components, said barrier forming apparatus including:

• a first reservoir for storing the first component;
• a second reservoir for storing the second component;
• an applicator having an applicator outlet and an applicator inlet;
• a mixing chamber having a first port that is in fluid communication with said first reservoir, a second port that is in fluid communication with said second reservoir and a third port that is in fluid communication with said applicator inlet;
• clearing means that is adapted to expel residue barrier mixture contained in said applicator and said mixing chamber through said applicator, including a third reservoir for storing a clearing fluid that is in fluid communication with said first and said second ports via respective first and second paths, said third reservoir being also in fluid communication with said applicator via a third path and whereby said clearing means includes supply means for providing a regular supply of the clearing fluid to said applicator via said third path, and
• control means having monitoring means for monitoring the resistance to the flow of the clearing fluid through said applicator outlet, and actuation means for actuating the production of the barrier mixture in said mixing chamber and its subsequent disbursement by said applicator, whereby production of the barrier mixture may occur if there is no resistance to the flow of clearing fluid passing through said applicator outlet or the level of resistance does not exceed a predetermined limit.

A barrier forming apparatus for forming a barrier between an exposed tunnel face and a tunnel boring machine, the barrier being formed by the application to the tunnel face of a barrier mixture comprising two highly reactive first and second components, said barrier forming apparatus including:

• a first reservoir for storing the first component;
• a second reservoir for storing the second component;
• a plurality of applicators each having an applicator outlet and an applicator inlet;
• a plurality of mixing chambers each having a first port that is in fluid communication with said first reservoir, a second port that is in fluid communication with said second reservoir and a third port that is in fluid communication with a respective one of said applicator inlets;
• clearing means that is adapted to expel residue barrier mixture contained in said applicators and said mixing chambers through said applicators, including a third reservoir for storing a clearing fluid, said third reservoir being in fluid communication with each of said applicators, and supply means for supplying a regular flow of the clearing fluid to each of said applicators;
• control means having monitoring means for monitoring the resistance to the flow of the clearing fluid through said applicator outlets, and actuation means for actuating the production of the barrier mixture in said mixing chambers and its subsequent disbursement by said applicators, whereby the production of barrier mixture in any one of said mixing chambers may occur if there is no resistance to the flow of clearing fluid passing through said applicator in fluid communication with said mixing chamber, or the level of resistance does not exceed a predetermined limit.

A barrier forming apparatus for forming a barrier between an exposed tunnel face and a tunnel boring machine, the barrier being formed by the application to the surface

• of a barrier mixture comprising two highly reactive first and second components, said barrier forming apparatus including:
• a first reservoir for storing the first component;
• a second reservoir for storing the second component;
• a plurality of applicators each having an applicator outlet and an applicator inlet;
• a plurality of mixing chambers each having a first port that is in fluid communication with said first reservoir, a second port that is in fluid communication with said second reservoir and a third port that is in fluid communication with a respective one of said applicator inlets;
• clearing means that is adapted to expel residue barrier mixture contained in said applicators and said mixing chambers through said applicators, including a third reservoir for storing a clearing fluid, said third reservoir being in fluid communication with each of said applicators, and supply means for supplying a regular flow of the clearing fluid to each of said applicators;
• control means having monitoring means for the sequential monitoring of resistance to the flow of the clearing fluid through each of said applicator outlets, and actuation means for actuating the production of the barrier mixture in said mixing chambers in sequential order and its subsequent disbursement by said applicators and the clearing of barrier mixture from said mixing chambers and said applicators immediately the supply of reagents to a mixing chamber is terminated, and whereby the production of barrier mixture in any one of said mixing chambers may occur if there is no resistance to the flow of clearing fluid passing through said applicator in fluid communication with said mixing chamber, or the level of resistance does not exceed a predetermined limit.

A tunnel boring machine of the type having a forwardly located, rotating cutting wheel, followed by a main bearing, a thrust system and various trailing support mechanisms, said tunnel boring machine also having a barrier forming apparatus for forming a barrier between an exposed tunnel face and the tunnel boring machine adjacent the machine, the barrier being formed by the application to the surface of a barrier mixture comprising two highly reactive first and second components, said tunnel boring machine including:

• a first reservoir for storing the first component;
• a second reservoir for storing the second component;
• an applicator having an applicator outlet and an applicator inlet;
• a mixing chamber having a first port that is in fluid communication with said first reservoir, a second port that is in fluid communication with said second reservoir and a third port that is in fluid communication with said applicator inlet;
• clearing means that is adapted to expel residue barrier mixture contained in said applicator and said mixing chamber through said applicator, including a third reservoir for storing a clearing fluid, said third reservoir being in fluid communication with said applicator, and supply means for providing a regular flow of the clearing fluid to said applicator, and
• control means having monitoring means for monitoring the resistance to the flow of the clearing fluid through said applicator outlet, and actuation means for actuating the production of the barrier mixture in said mixing chamber and
• its subsequent disbursement by said applicator, whereby production of the barrier mixture may occur if there is no resistance to the flow of clearing fluid passing through said applicator outlet or the level of resistance does not exceed a predetermined limit.