Process for treating keratin fibres, especially the hair, preferably for shaping and/or conditioning the hair, which comprises the application of a composition (A) comprising: (a) one or more alkoxysilanes bearing solubilizing function(s) of formula (I) below, and/or hydrolysis products thereof and/or oligomers thereof: R 1 S 1 (OR 2 ) z (R 3 ) x (OH) y (I) in which: R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH2 or NHR, R being: ∘ a C 1 -C 20 and preferably C 1 -C 6 alkyl group optionally substituted with a group comprising a silicon atom, better still a group (R 2 O) 3 Si-, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group, R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, (b) one or more alkylalkoxysilanes of formula (III) below, and/or hydrolysis products thereof and/or oligomers thereof: (R 4 ) m Si(OR 5 ) n (III) in which: R 4 and R 5 each represent, independently of each other, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4, and (c) water in an amount of greater than 30% by weight relative to the total weight of the composition. (a) one or more alkoxysilanes bearing solubilizing function(s) of formula (I) below, and/or hydrolysis products thereof and/or oligomers thereof: R 1 S 1 (OR 2 ) z (R 3 ) x (OH) y (I) in which: R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH2 or NHR, R being: ∘ a C 1 -C 20 and preferably C 1 -C 6 alkyl group optionally substituted with a group comprising a silicon atom, better still a group (R 2 O) 3 Si-, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group, R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, R 1 is a linear or branched, saturated or unsaturated C 1 -C 6 hydrocarbon-based chain, substituted with an amine group NH2 or NHR, R being: ∘ a C 1 -C 20 and preferably C 1 -C 6 alkyl group optionally substituted with a group comprising a silicon atom, better still a group (R 2 O) 3 Si-, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group, ∘ a C 1 -C 20 and preferably C 1 -C 6 alkyl group optionally substituted with a group comprising a silicon atom, better still a group (R 2 O) 3 Si-, ∘ a C 3 -C 40 cycloalkyl or ∘ a C 6 -C 30 aromatic group, R 2 and R 3 , which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms, y denotes an integer ranging from 0 to 3, z denotes an integer ranging from 0 to 3, and x denotes an integer ranging from 0 to 2, with z + x + y = 3, (b) one or more alkylalkoxysilanes of formula (III) below, and/or hydrolysis products thereof and/or oligomers thereof: (R 4 ) m Si(OR 5 ) n (III) in which: R 4 and R 5 each represent, independently of each other, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4, and R 4 and R 5 each represent, independently of each other, a C 1-6 , better still C 1-4 , alkyl group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl, n ranges from 1 to 3, m ranges from 1 to 3, on condition that m+n=4, (c) water in an amount of greater than 30% by weight relative to the total weight of the composition. <EOS>