A turbine ring assembly comprising a plurality of ring sectors (10a, 10b) forming a turbine ring and a ring support structure, each ring sector (10a, 10b) having, in a section plane defined by an axial direction (D A) and a radial direction (D R) of the ring and orthogonal to a circumferential direction (D C) of the turbine ring, a part forming an annular base with, in the radial direction (D R) of the turbine ring, an internal face defining the internal face of the turbine ring and an external face from which extend as projections a first and a second attachment tabs (14, 16), the ring support structure including a central shell ring from which extend as projections a first and a second radial flanges (32, 36) to retain each ring sector, and an annular ring-flange having a free first end seated against the first attachment tab and a second end opposite to the first end and cooperating with the first radial flange, each ring sector (10a, 10b) extending between a first circumferential end and a second circumferential end each intended to face another adjacent ring sector (10b, 10a) in the circumferential direction (D C), and comprising a first rectilinear seating surface positioned on an upstream face of the first attachment tab in contact with the annular ring-flange and a second rectilinear seating surface positioned on a downstream face of the second attachment tab in contact with the second radial flange, each of the first and second rectilinear seating surfaces extending along a tangent to the circumferential direction (D C) between the first and second circumferential ends (102, 104) of the ring sector (10a, 10b), characterized in that the rectilinear seating surfaces of each ring sector (10a, 10b) have, along said tangent to the circumferential direction (D C), a variable thickness in the axial direction (D A) with a minimum thickness at the first and second circumferential ends (102, 104) of the ring sector (10a, 10b) and a maximum thickness in a median portion of the rectilinear seating surface. the ring support structure including a central shell ring from which extend as projections a first and a second radial flanges (32, 36) to retain each ring sector, and an annular ring-flange having a free first end seated against the first attachment tab and a second end opposite to the first end and cooperating with the first radial flange, each ring sector (10a, 10b) extending between a first circumferential end and a second circumferential end each intended to face another adjacent ring sector (10b, 10a) in the circumferential direction (D C), and comprising a first rectilinear seating surface positioned on an upstream face of the first attachment tab in contact with the annular ring-flange and a second rectilinear seating surface positioned on a downstream face of the second attachment tab in contact with the second radial flange, each of the first and second rectilinear seating surfaces extending along a tangent to the circumferential direction (D C) between the first and second circumferential ends (102, 104) of the ring sector (10a, 10b), characterized in that the rectilinear seating surfaces of each ring sector (10a, 10b) have, along said tangent to the circumferential direction (D C), a variable thickness in the axial direction (D A) with a minimum thickness at the first and second circumferential ends (102, 104) of the ring sector (10a, 10b) and a maximum thickness in a median portion of the rectilinear seating surface.