Anti-ice pushing/pulling device installed on slope of earth-rock dam and ice thrust calculation method

An anti-ice pushing/pulling device installed on a dam slope of an earth-rock dam, is arranged in a groove formed on a surface of an upstream dam slope of the earth-rock dam in an area whose water level varies between a maximum level and a minimum level during winter;

• the anti-ice pushing/pulling device comprises an upper concrete slab and a lower concrete slab hinged by means of a rotating shaft structure, wherein the rotating shaft structure is located at an end of the groove on the dam slope, and the end of the groove is more distant from a dam crest than another end of the groove opposite to the end of the groove;
• a jack is arranged between the upper concrete slab and the lower concrete slab to adjust a flip angle of the upper concrete slab;
• a plurality of rectangular grooves are formed on a surface of the upper concrete slab, and a combined structure formed by splicing concrete blocks is arranged in the rectangular grooves;
• and holes are formed on the concrete blocks;
• a maximum flip angle of the upper concrete slab is 90° to a horizontal plane, and a minimum flip angle of the upper concrete slab is an angle of the dam slope;
• each of the concrete blocks is in a form of an isosceles right triangle, a hypotenuse of each of the concrete blocks is provided with an isosceles trapezoidal hole symmetric about a symmetry axis, and occlusal parts are formed on both sides of the isosceles trapezoidal hole;
• and the occlusal parts are used for occlusal splicing between the concrete blocks;
• a water-stop material is arranged on an edge of the lower concrete slab away from the rotating shaft structure to prevent water from flowing into an interlayer between the upper concrete slab and the lower concrete slab;
• wherein the anti-ice pushing/pulling device is configured to resist an ice thrust F on the dam slop of the earth-rock dam, and the ice thrust F is calculated by an equation as follows,
• F
• =
• 2
• ⁢
• 8
• ⁢
• 5
• ⁢
• α
• ⁢
• 1
• +
• m
• 2
• ⁢
• (
• h
• -
• 0
• .
• 3
• ⁢
• 5
• )
• 1
• 6
• ⁢
• (
• ∇
• t
• T
• )
• 0
• .
• 1
• [
• (
• 2
• ⁢
• 0
• ⁢
• 0
• ⁢
• 0
• ⁢
• h
• v
• 3
• ⁢
• H
• 0
• .
• 1
• -
• 3
• ⁢
• 6
• ⁢
• 0
• )
• 1
• 1
• ⁢
• 2
• -
• 0
• .
• 7
• ⁢
• 2
• ]
• wherein F is the ice thrust, kN/m;
• a is a material coefficient of the upper concrete slab, a=a1*a2*a3, a1 is a surface roughness, a2 is a shape coefficient, a3 is a contact condition coefficient, a1 is 1.2, a2 is 1.5, and a3 is 0.5;
• m is a slope of the upper concrete slab;
• h is a maximum ice thickness of a day, m;
• (∇t/T) is a temperature rise rate, ∇t is an absolute value of a difference between an average temperature and a maximum or minimum temperature of the day, ° C.;
• T is a temperature rise time, h;
• v is an average wind speed, m/s;
• and H is a water depth in front of the earth-rock dam, m;
• wherein the anti-ice pushing/pulling device is configured to reduce a maximum ice thickness which is calculated as follows,
• h
• 0
• =
• (
• 1
• -
• K
• 1
• ⁢
• C
• 1
• ⁢
• d
• S
• -
• K
• 2
• ⁢
• θ
• 1
• θ
• )
• ⁢
• h
• wherein h0 is the maximum ice thickness after reduction, m;
• K1 and K2 are coefficients, and K1 and K2 are 0.1 and 0.15, respectively;
• C1 is a perimeter of a vertical projected area of all unfilled parts of the rectangular grooves of the upper concrete slab on the dam slope, m;
• d is a thickness of each of the concrete blocks, m;
• S is a projected area of the upper concrete slab on the dam slope, m2;
• θ1 is an angle between the upper concrete slab and the horizontal plane after flipping and unfolding, rad;
• θ is an angle between the upstream dam slope and the horizontal plane, rad;
• and
• the maximum ice thickness h0 after reduction is substituted into the equation for the ice thrust to calculate the ice thrust after reduction.