Ground reinforcement structure and construction method thereof

A method of installing the ground reinforcement structure,

• wherein a ground reinforcement structure is installed on a ground (10) in which a sandy soil layer (11) having a weak surface layer is provided and thus large-caliber excavation is difficult to be performed, and
• the ground reinforcement structure comprising a ground reinforcement member (100) comprises:
• an expansion-type steel pipe (110) inserted to be installed in a small-caliber drilled portion (A), wherein the small-caliber drilled portion (A) having a diameter of 51 mm to 61 mm and expanded by hydraulic pressure;
• and a settlement member (120) coupled to a rear end of the expansion-type steel pipe (110),
• wherein the expansion-type steel pipe (110) is inserted into the sandy soil layer (11), and the settlement member (120) is inserted into a rock layer (12),
• wherein a grout injection pipe (210) is coupled along an outer circumferential surface of the ground reinforcement member (100) to fill grout (200) into a gap between the drilled portion (A) and the ground reinforcement member (100),
• wherein the ground reinforcement structure, further comprises a packing part (130) installed on an outer circumferential surface of the expansion-type steel pipe (110) to block an inlet of the drilled portion (A) to prevent the grout (200) from flowing to the outside of the drilled portion while the grout (200) is filled,
• wherein the packing part (130) comprises:
• a through-hole (131) through which the injection pipe (210) passes;
• and a grout discharge hole (132) for checking discharge of the grout (200) that is completely filled,
• wherein the settlement member (120) is made of a steel pipe, a grout introduction hole is defined in an outer circumferential surface of the settlement member (120), and the grout (200) injected through the grout injection pipe (210) installed along the outer circumferential surfaces of the expansion-type steel pipe (110) and the settlement member (120) is filled in the drilled portion (A) and an outside of the combined ground reinforcement member (100), and filled in an inside of the settlement member (120) through an introduction hole (121),
• the method comprising:
• a ground drilling process of defining the drilled portion (A) having a diameter of 51 mm to 61 mm up to the rock layer (12);
• a ground reinforcement member installation process of installing the ground reinforcement member (100) to insert the settlement member (120) into the rock layer (12);
• a grout filling process of filling the grout (200) into a gap between the drilled portion (A) and the ground reinforcement member (100) and the inside of the settlement member (120);
• and
• an expansion-type steel pipe expansion process of expanding the expansion-type steel pipe (110) by using hydraulic pressure.

A method of installing the ground reinforcement structure,

• wherein a ground reinforcement structure is installed on a ground (10) in which a sandy soil layer (11) having a weak surface layer is provided and thus large-caliber excavation is difficult to be performed, and
• the ground reinforcement structure comprising a ground reinforcement member (100) comprises:
• an expansion-type steel pipe (110) inserted to be installed in a small-caliber drilled portion (A), wherein the small-caliber drilled portion (A) having a diameter of 51 mm to 61 mm and expanded by hydraulic pressure;
• and a settlement member (120) coupled to a rear end of the expansion-type steel pipe (110),
• wherein the expansion-type steel pipe (110) is inserted into the sandy soil layer (11), and the settlement member (120) is inserted into a rock layer (12),
• wherein a grout injection pipe (210) is coupled along an outer circumferential surface of the ground reinforcement member (100) to fill grout (200) into a gap between the drilled portion (A) and the ground reinforcement member (100),
• wherein the ground reinforcement structure, further comprises a packing part (130) installed on an outer circumferential surface of the expansion-type steel pipe (110) to block an inlet of the drilled portion (A) to prevent the grout (200) from flowing to the outside of the drilled portion while the grout (200) is filled,
• wherein the packing part (130) comprises:
• a through-hole (131) through which the injection pipe (210) passes;
• and a grout discharge hole (132) for checking discharge of the grout (200) that is completely filled,
• wherein the settlement member (120) is made of a steel pipe, a grout introduction hole is defined in an outer circumferential surface of the settlement member (120), and the grout (200) injected through the grout injection pipe (210) installed along the outer circumferential surfaces of the expansion-type steel pipe (110) and the settlement member (120) is filled in the drilled portion (A) and an outside of the combined ground reinforcement member (100), and filled in an inside of the settlement member (120) through an introduction hole (121),
• wherein the settlement member (120) further comprises a pair of horseshoe-type shear reinforcement member (123) passing through the introduction hole (121) and coupled to each other to improve coupling force between the settlement member (120) and the grout (200),
• the method comprising:
• a ground drilling process of defining the drilled portion (A) having a diameter of 51 mm to 61 mm up to the rock layer (12);
• a ground reinforcement member installation process of installing the ground reinforcement member (100) to insert the settlement member (120) into the rock layer (12);
• a grout filling process of filling the grout (200) into a gap between the drilled portion (A) and the ground reinforcement member (100) and the inside of the settlement member (120);
• and
• an expansion-type steel pipe expansion process of expanding the expansion-type steel pipe (110) by using hydraulic pressure.