Random road profile into ode45

clc,clear all

k_s = 26400;
m = 483; %Mass
f_n = sqrt(k_s/m)/(2*pi); %Natural frequency in Hz

%% Road profile

% spatial frequency (n0) cycles per meter
Omega0 = 0.1; %%%%conventional value of spatial frequency(n0)?
% psd ISO (used for formula 8)
Gd_0 =  32 * (10^-6);
% waveviness
w = 2; 
% road length
L = 250;

%delta n 
N = 1000; 
Omega_L = 0.004;
Omega_U = 4;

delta_n =  1/L; % delta_n = (Omega_U - Omega_L)/(N-1);

% spatial frequency band
Omega = Omega_L:delta_n:Omega_U;
 
%PSD of road
Gd = Gd_0.*(Omega./Omega0).^(-w);

% calculate amplitude using formula(8) in the article
%Amp = sqrt(2*Gd*delta_n); %%%from Eq. 7?

%calculate amplitude using simplified formula(9) in the article
k = 3; %%%upper limit A and lower limit B k=3?
%Amp = sqrt(delta_n) * (2^k) * (10^-3) * (Omega0./Omega);
Amp = sqrt(delta_n) * (2^k) * (10^-3) * (Omega0./Omega);

%random phases 
Psi = 2*pi*rand(size(Omega)); 

% x abicsa from 0 to L
x1 = 0:0.25:250;
% road sinal
h= zeros(size(x1));
plot(x1, h*1000);

%% ode45
T = 110;
x0 = [0,0];
 
for iv=1:length(x1)
    h(iv) = sum( Amp.*cos(2*pi*Omega*x1(iv) + Psi) );
    
        f = @(t,x) [ x(2); -( k_s*(x(1)-1000*h(iv))/ m ) ];
        
        [t, x] = ode45(f,[100,T],x0);
    
end

plot(t,x(:,1));

Hi, I generated a random road profile (h) and it gives such a figure as below,

As you can see, there are quite lots of elevation in this road profile. However, if I apply this into my ode45, it gives a graph as below,

this seems to be a sinosoidal graph, but I think this graph should not be like this because the road has lots of elevation during the journey.

Can any one tell me what is wrong with my code please?